Drought stress-mediated differences in phyllosphere microbiome and associated pathogen resistance between male and female poplars.

Phyllosphere-associated microbes play a crucial role in plant-pathogen interactions while their composition and diversity are strongly influenced by drought stress. As dioecious plant species exhibited secondary dimorphism between the two sexes in response to drought stress, whether such difference will lead to sex-specific differences in phyllosphere microbiome and associated pathogen resistance between male and female conspecifics is still unknown. In this study, we subjected female and male full siblings of a dioecious poplar species to a short period of drought treatment followed by artificial infection of a leaf pathogenic fungus. Our results showed that male plants grew better than females with or without drought stress. Female control plants had more leaf lesion area than males after pathogen infection, whereas drought stress reversed such a difference. Further correlation and in vitro toxicity tests suggested that drought-mediated sexual differences in pathogen resistance between the two plant sexes could be attributed to the shifts in structure and function of phyllosphere-associated microbiome rather than the amount of leaf main defensive chemicals contained in plant leaves. Supportively, the microbiome analysis through high-throughput sequencing indicated that female phyllosphere enriched a higher abundance of ecologically beneficial microbes that serve as biological plant protectants, while males harbored abundant phytopathogens under drought-stressed conditions. The results could provide potential implications for the selection of suitable poplar sex to plants in drought or semi-drought habitats.

Expression of a thermostable glucose-stimulated ß-glucosidase from a hot-spring metagenome and its promising application to produce gardenia blue.

This study reports a thermostable glucose-stimulated ß-glucosidase, BglY442, from hot-spring metagenomic data that was cloned and expressed in Escherichia coli BL21 (DE3). The molecular mass of recombinant BglY442 was 69.9 kDa and was used in the production of gardenia blue. The recombinant BglY442 showed its maximum activity at pH 6.0 and 75 °C, maintained 50 % activity at 70 °C for 36 h, presented over 90 % activity in a broad pH range and a wide range of pH stability. Moreover, BglY442 exhibited excellent tolerance toward methanol and ethanol. The specific activity of BglY442 was 235 U/mg at pH 6.0 and 75 °C with 10 mM pNPG as substrate. BglY442 activity increased by over fourfold with 2 M glucose or xylose. Specifically, the enzyme kinetics of BglY442 seem to be non-Michaelis-Menten kinetics or atypical kinetics because the Michaelis-Menten saturation kinetics were not observed with pNPG, oNPG or geniposide as substrates. Under optimum conditions, geniposide was dehydrated by BglY442 and reacted with nine amino acids respectively by the one-pot method. Only the Arg or Met derived pigments showed bright blue, and these two pigments had similar ultraviolet absorption spectra. The OD590 nm of GB was detected to be 1.06 after 24 h with the addition of Arg and 1.61 after 36 h with the addition of Met. The intermediate was elucidated and identified as ginipin. Molecular docking analysis indicated that the enzyme had a similar catalytic mechanism to the reported GH1 Bgls. BglY442 exhibited potential for gardenia blue production by the one-pot method. With outstanding thermostability and glucose tolerance, BglY442 should be considered a potential ß-glucosidase in biotechnology applications.

Soil cadmium stress affects the phyllosphere microbiome and associated pathogen resistance differently in male and female poplars.

Microorganisms associated with the phyllosphere play a crucial role in protecting plants from diseases, and their composition and diversity are strongly influenced by heavy metal contaminants. Dioecious plants are known to exhibit sexual dimorphism in metal accumulation and tolerance between male and female individuals. Hence, in this study we used male and female full-siblings of Populus deltoides to investigate whether the two sexes present differences in their phyllosphere microbiome structures and in their associated resistance to the leaf pathogenic fungus Pestalotiopsis microspora after exposure to excess soil cadmium (Cd). We found that Cd-treated male plants grew better and accumulated more leaf Cd than females. Cd stress reduced the lesion areas on leaves of both sexes after pathogen infection, but male plants exhibited better resistance than females. More importantly, Cd exposure differentially altered the structure and function of the phyllosphere microbiomes between the male and female plants, with more abundant ecologically beneficial microbes and decreased pathogenic fungal taxa harbored by male plants. In vitro toxicity tests suggested that the sexual difference in pathogen resistance could be attribute to both direct Cd toxicity and indirect shifts in the phyllosphere microbiome. This study provides new information relevant for understanding the underlying mechanisms of the effects of heavy metals involved in plant-pathogen interactions.

Leaf spot disease on Juglans regia caused by Ragnhildiana diffusa in China.

Juglans regia L. is commercially important for its edible nuts, which is a major species of walnut trees in Sichuan Province (Luo et al. 2020). In September 2021, brown leaf spot symptoms were observed on roughly 75% of 60 J. regia trees surveyed in an orchard of Chongzhou city (30°40'6''N, 103°40'18''E). Initially, the lesions measuring 2-10 mm were reddish to brown with a yellowish halo, then increased in size and coalesced to cover the whole leaf, eventually resulting in severe defoliation. Six symptomatic leaves from different trees were collected, and a single fungal isolate was obtained from each of the sampled leaves using single-spore isolation (Chomnunti et al. 2014). The isolates were incubated on potato dextrose agar (PDA) with a 12h photoperiod at 25 ℃, and deposited at the Culture Collection of Sichuan Agricultural University. Colonies were identical with black center and reddish-brown periphery, and the diameter reached 2 cm after 7 days. On the host, conidiophores were mostly reduced to conidiogenous cells, with prominent and thickened conidiogenous loci. Conidia were light green to light brown, and curved with a thickened and darked hilum at the base, 0-17 septate, tapering toward the distal end, and measuring 20-120 × 3-5 µm ((x ) ̅= 56 × 4, n = 30). Morphological characteristics fit the description of Ragnhildiana diffusa (Heald & F.A. Wolf) Videira & Crous (Synonym: Sirosporium diffusum (Heald & F. A. Wolf) Deighton) (Poletto et al. 2017). The internal transcribed spacer (ITS) region, the large subunit of the nrDNA (LSU), and RNA polymerase II second largest subunit (rpb2) were amplified by polymerase chain reaction and sequenced with primers ITS5/ITS4 (White et al. 1990), LR0R/LR5 (Vilgalys & Hester 1990), fRPB2-5F/Rpb2-R3 (Liu et al. 1999, Videira et al. 2017), respectively. The nucleotide blast of the two isolates (SICAUCC 22-0077, SICAUCC 22-0078) showed 99.7% and 99.5% (ITS, 472/473 bp, 471/473 bp), 100% (LSU, 725/725 bp, 725/725 bp), 99.8% (rpb2, 866/867 bp, 866/867 bp) identities with the ex-type strain of Ragnhildiana diffusa (CBS 106.14). The phylogenetic tree combined with ITS, LSU, and rpb2 genes and morphological characteristics confirmed the identification as R. diffusa. These sequences of the three gene regions of two isolates were deposited in GenBank with accession numbers ON409525 and ON409526 (ITS), ON409559 and ON409560 (LSU), ON417473 and ON417474 (rpb2), respectively. The isolate SICAUCC 22-0077 was used for pathogenicity test to fulfill Koch's postulates. Three leaves of each walnut seedlings (2-year-old seedlings) were inoculated by placing a mycelium plug onto fresh wounds on the upper leaf surface punctured via a fine needle (0.7 mm in diameter), and three replicate seedlings were inoculated. For the control, a sterile PDA plug was placed on the same number of replicate leaves on the plants. The inoculated and control plants were placed in a growth chamber at 25°C with relative humidity >80% and a 12-h photoperiod. Irregular light to dark brown spots developed on inoculated leaves after twenty days, and no symptoms were observed on controls. The re-isolation and examination of the fungus showed it to be morphologically and phylogenetically identical to the originally isolated pathogen. R. diffusa has been described on J. regia in Mexico (Farr & Rossman 2022). To our knowledge, this is the first report of R. diffusa causing brown leaf spot on J. regia in China. The identification of the pathogen will provide a basis for disease management in walnut planting areas.

Trunk rot of Juglans regia caused by Myrmaecium fulvopruinatum in China.

Walnut (Juglans regia) is a deciduous tree of the Juglandaceae family, widely cultivated in China, and provides value in a variety of ways, including the usage of the wood and nuts, and offers substantial economic, social, and environmental advantages (Wang et al, 2017). Nevertheless, a fungal disease of causing walnut trunk rot was observed in approximately 30% of 50 counted ten-year-old J. regia in Chongzhou City (30°33'34″N, 103°38'35″E, 513 m), Sichuan Province, China, and this disease has greatly delete healthy growth of walnut. The infected bark exhibited purple necrotic lesions, and the sick parts were surrounded by water-soaked plaques. From 10 trunks of the 10 diseased trees, 20 isolated fungal colonies were the same. The ascospores placed in 60 mm plates were almost entirely covered with mycelium within 8 days, colonies on the PDA changed from initial pale to white, ad then turned yellowish to light orange or rosy to yellow-brown (25℃, 90% relative humidity, 12-h photoperiod). On the host, Ectostromata were immersed to erumpent, globose to subglobose, purple and brown, and measured 0.6 - 4.5 × 0.3 - 2.8 mm (x̄ = 2.6 × 1.6 mm, n = 40); Ascomata were flask-shaped to subglobose, dark brown, and measured 0.1 - 0.6 × 0.1 - 0.4 mm (x̄ = 0.35 × 0.25 mm, n = 40); Asci were numerous, cylindrical to subclavate, contained 8 uniseriate ascospores, and measured 80 - 150 × 10 - 20 µm (x̄ = 115 × 15 µm, n = 40), and Ascospores were ellipsoid, 2-celled, dark brown to black, plump or attenuated towards, apices with 1 large drop per cell, and measured 14 - 20 × 6.5 - 9 µm (x̄ = 17 × 7.8 µm, n = 40). These morphological characteristics are consistent with the species Myrmaecium fulvopruinatum (Berk.) Jaklitsch & Voglmayr (Jaklitsch et al. 2015). The genomic DNA of a representative isolate SICAUCC 22-0148 was extracted. The ITS, LSU region, tef1-α, rpb2 genes region were amplified using the primer pairs ITS1/ITS4 primers (White et al. 1990), LR0R/LR5 (Moncalvo et al. 1995), EF1-688F/986R (Alves et al. 2008), fRPB2-5f/fRPB2-7cr (Liu et al. 1999), respectively. The sequences were deposited in NCBI with accession numbers ON287043 (ITS), ON287044 (LSU), ON315870 (tef1-α), and ON315871 (rpb2), rspectively, which showed 99.8, 99.8, 98.1, and 98.5% identities with M. fulvopruinatum CBS 139057 holotype (accession numbers KP687858, KP687858, KP688027, and KP687933 respectively). Based on the analyses of phylogenies and morphologies, the isolates were identified as M. fulvopruinatum. The pathogenicity of SICAUCC 22-0148 was tested by inoculating surface-sterilized trunk wounds of four-year-old trees of J. regia with a mycelial plug (Desai et al. 2019). Sterile PDA plugs were used as controls. Wounds were covered with a film, to ensure humidity and prevent contamination. Each inoculation was repeated twice and included two plants, control and inoculated. A month later, the symptoms observed on inoculated trunks were similar to those in the wild, and M. fulvopruinatum was re-isolated from the inoculated trunk, confirming Koch's postulates. Previous research has reported M. fulvopruinatum as an important fungal species that cause canker delete symptoms on Chinese sweet chestnut in China (Jiang et al. 2018). We carried the taxonomy work of the fungi that caused trunk rot on walnut, and this is the first time that M. fulvopruinatum has been linked to walnut trunk rot on J. regia. Trunk rot of walnut will not only cause weakening of trees, but also affect the yield and quality of walnuts, bringing huge economic losses. This study was supported by the Sichuan Science and Technology Program under Grant 2022NSFSC1011. References: Alves, A., et al. 2008. Fungal Diversity 28:1-13. Desai, D.D., et al. 2019. International Journal of Economic Plants 6:147-149. Jaklitsch., W.M., et al. 2015. Fungal Diversity 73(1):159-202. Jiang, N., et al. 2018. Mycosphere 9(6):1268-1289. Liu, Y.L., et al. 1999. Mol Biol Evol 16:1799-1808. Moncalvo, J.M., et al. 1995. Mycologia 87:223-238. Wang, Q.H., et al. 2017. Australasian Plant Pathology 46:585-595. White, T.J., et al. 1990. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA.

Colletotrichum fructicola Causal agent of Shot-Hole Symptoms on Leaves of Prunus sibirica in China.

Prunus sibirica L. (Siberian apricot) is a member of the Rosaceae family and an ecologically important tree species in China (Buer et al., 2022). Shot hole symptoms on the leaves were observed in five Siberian apricot groves in Chengdu (103.81 E, 30.97 N), Sichuan province in July 2020. The symptoms first appeared as small purplish-brown spots with yellow rings around them. As the disease progressed, the damaged area (diameter 1.5-3.0 cm) became necrotic and fell off. The disease incidence was about 60% and the disease index was 28.6 of leaves in the grove. in most severe cases. Fifteen symptomatic leaves were collected from 5 different trees in an orchard. Pathogen isolation was performed from symptomatic leaf tissue (5 × 5 mm) though surface disinfection (in 70% ethanol and 2% NaClO) and incubation on Potato Dextrose Agar (PDA) at 28℃ for 3 days. Overall 10 isolates with similar colony morphology were obtained from the 15 infected tissue pieces, and three representative isolates (XCK 2-4) were selected for further study. Colonies of the isolates on PDA were initially cottony, pale white to grayish-green with abundant aerial hyphae and produced conidial masses after 7 days. Conidiogenous cells were clavate and aggregated in acervuli. Conidia were smooth-walled, single-celled, straight, and slightly obtusely rounded at both ends, 12.8 to 18.7 × 4.3 to 5.7 µm in size (Fig. 1). The morphological characteristics of the three isolates were consistent with the description of species in the Colletotrichum gloeosporioides complex. DNA was amplified using the following primers pairs for the internal transcribed spacer (ITS) region of rDNA and partial sequences of beta-tubulin (TUB2), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), chitin synthase (CHS-1), and translation elongation factor (TEF-1), respectively: ITS1/ITS4, T1/Bt2b, GDF/GDR, CHS-F/CHS-R, and EF-F/EF-R (Vieira et al., 2014). Accession numbers (MW228049, MW284974, MW284976, MW284975 and MW284977, respectively) were obtained afterepositing all the resulting sequences in GenBank. Nucleotide blast showed 99 to 100% identities with Colletotrichum fructicola (GenBank accessions nos. MZ961683, MW284974, MN525881, MN525860, MF627961). Phylogenetic analysis of combined ITS-TUB-GAPDH genes using the Mrbayes inference method showed that the three isolates clustered with three reference isolates of C. fructicola as a distinct clade (Fig. 2). To verify Koch's postulates, ten 3-year-old healthy potted plants of P. sibirica were inoculated by spraying a conidial suspension (6 × 105 conidia/mL) of isolate XCK2 on both sides of leaves, and the control leaves were sprayed with sterile water. Then, all treatments were placed in a moist environment (25±2°C, 80% relative humidity, natural light). The inoculated plants showed typical symptoms of plants with natural infections, while the controls remained asymptomatic after 14 days. The pathogen C. fructicola was re-isolated from all inoculated plants, and the culture and fungus characteristics were the same as those of the original isolate. Colletotrichum fructicola was not isolated from the control plants. The results indicated that C. fructicola is the causal agent of the disease. Colletotrichum fructicola was reported as a leaf pathogen on Camellia chrysantha in China (Zhao et al., 2021). This is the first report of C. fructicola causing P. sibirica leaf shot-hole in the world. The identification of C. fructicola could provide relevant information for applying management strategies and research on the Siberian apricot disease.

Nigrospora musae Causing Taxus chinensis var. mairei stem blight in Sichuan, China.

Taxus chinensis var. mairei is the endemic, endangered, and first-class protected tree species in China. This species is considered as an important resource plant because it can produce Taxol which is an effective medicinal compound against various cancers (Zhang et al., 2010). Stem blight was observed in two plant nurseries in Ya'an (102°44'E,30°42'N), Sichuan province in April 2021. The symptoms first appeared as round brown spots on the stem. As the disease progressed, the damaged area gradually expanded into an oval or irregular shape, which was dark brown. About 800 square meters of planting area were investigated and the disease incidence was up to approximately 64.8%. Twenty obviously symptomatic stems which exhibited the same symptoms as above were collected from 5 different trees in the nursery. To isolate the pathogen, the symptom margin was cut into small blocks (5 x 5 mm), and the blocks were surface sterilized in 75% ethanol for 90 s and 3% NaClO solution for 60 s . Finally incubated on Potato Dextrose Agar (PDA) at 28℃ for 5 days. Ten pure cultures were isolated by transferring hyphal and the three strains (HDS06, HDS07 and HDS08) were selected as representative isolates for further study. Initially, colonies on the PDA of three isolates were white and cotton-like, and then gradually turned gray-black from the center. After 21 days, conidia were produced and were smooth-walled, single-celled, black, oblate, or spherical, measuring 9.3 to 13.6 × 10.1 to 14.5 µm in size (n = 50). Conidia were present at the tip of conidiophores on hyaline vesicles. These morphological features were generally consistent with those of N. musae (Wang et al., 2017). To validate the identification, DNA were extracted from the three isolates, followed by the amplification of transcribed spacer region of rDNA (ITS), the translation elongation factor EF-1 (TEF-1), and the Beta-tubulin (TUB2) sequences with the respective primer pairs ITS1/ITS4 (White et al., 1990), EF-728F/EF-986R (Vieira et al., 2014) and Bt2a/Bt2b (O'Donnell et al., 1997) .The sequences were deposited in GenBank with the accession numbers ON965533, OP028064, OP028068, OP060349, OP060353, OP060354, OP060350, OP060351 and OP060352, respectively. Phylogenetic analysis of combined ITS, TUB2, and TEF genes using the Mrbayes inference method showed that the three isolates clustered with Nigrospora musae as a distinct clade (Fig. 2). Combine with morphological characteristics and phylogenetic analysis, three isolates were identified as N. musae. 30 2-year-old healthy potted plants of T. chinensis were used for pathogenicity test. 25 of these plants were inoculated by injecting 10 µL of the conidia suspension (1 × 106 conidia/mL) into stems and then wrap around the seal to moisturize. The remaining 5 plants were injected with the same amount of sterilized distilled water as a control. Finally, all potted plants were placed in a greenhouse at 25°C and 80% relative humidity. After 2 weeks, the inoculated stems developed lesions similar to those observed in the field, whereas controls were asymptomatic. N. musae was re-isolated from the infected stem and identified by both morphological characteristics and DNA sequence analysis. The experiments repeated three times showed similar results. As far as we know, this is the first report of N. musae causing T. chinensis stem blight in the world. The identification of N. musae could provide a certain theoretical basis for field management and further research of T. chinensis.

Molecular and Functional Characterization of Pheromone Binding Protein 2 from Cyrtotrachelus buqueti (Coleoptera: Curculionidae).

Pheromone-binding proteins (PBPs) play important roles in binding and transporting sex pheromones. However, the PBP genes identified in coleopteran insects and their information sensing mechanism are largely unknown. Cyrtotrachelus buqueti (Coleoptera: Curculionidae) is a major insect pest of bamboo plantations. In this study, a novel PBP gene, CbuqPBP2, from C. buqueti was functionally characterized. CbuqPBP2 was more abundantly expressed in the antennae of both sexes than other body parts, and its expression level was significantly male-biased. Fluorescence competitive binding assays showed that CbuqPBP2 exhibited the strongest binding affinity to dibutyl phthalate (Ki = 6.32 µM), followed by styrene (Ki = 11.37 µM), among twelve C. buqueti volatiles. CbuqPBP2, on the other hand, showed high binding affinity to linalool (Ki = 10.55), the main volatile of host plant Neosinocalamus affinis. Furthermore, molecular docking also demonstrated the strong binding ability of CbuqPBP2 to dibutyl phthalate, styrene, and linalool, with binding energy values of -5.7, -6.6, and -6.0 kcal/mol, respectively, and hydrophobic interactions were the prevailing forces. The knockdown of CbuqPBP2 expression via RNA interference significantly reduced the electroantennography (EAG) responses of male adults to dibutyl phthalate and styrene. In conclusion, these results will be conducive to understanding the olfactory mechanisms of C. buqueti and promoting the development of novel strategies for controlling this insect pest.

Diabetes mellitus aggravates humoral immune response in myasthenia gravis by promoting differentiation and activation of circulating Tfh cells.

Myasthenia gravis (MG) is a T-cell-dependent, antibody-mediated autoimmune disease. Diabetes mellitus (DM) is a chronic metabolic disease characterized by hyperglycemia and emerging evidence indicates its profound impacts on the immune homeostasis. Previous studies and our data showed DM might serve as an independent risk factor of MG, yet the underlying immune and molecular mechanisms remain to be addressed. Our study observed that circulating Tfh (cTfh) cells were increased in MG patients with DM and expressed a high level of ICOS. Besides, positive correlations between activated cTfh cells and plasmablasts were documented. Further studies demonstrated hyperglycemia promoted the differentiation and activation of Tfh cells which, in turn, caused abnormal plasmablasts differentiation and antibody secretion through the mTOR signaling pathway. These results indicated DM might aggravate the aberrant humoral immunity in MG patients by augmenting Tfh cells differentiation and function and tight glycemic control might be beneficial for MG patients with DM.

Percolation transitions in interdependent networks with reinforced dependency links.

Dependence can highly increase the vulnerability of interdependent networks under cascading failure. Recent studies have shown that a constant density of reinforced nodes can prevent catastrophic network collapses. However, the effect of reinforcing dependency links in interdependent networks has rarely been addressed. Here, we develop a percolation model for studying interdependent networks by introducing a fraction of reinforced dependency links. We find that there is a minimum fraction of dependency links that need to be reinforced to prevent the network from abrupt transition, and it can serve as the boundary value to distinguish between the first- and second-order phase transitions of the network. We give both analytical and numerical solutions to the minimum fraction of reinforced dependency links for random and scale-free networks. Interestingly, it is found that the upper bound of this fraction is a constant 0.088 01 for two interdependent random networks regardless of the average degree. In particular, we find that the proposed method has higher reinforcement efficiency compared to the node-reinforced method, and its superiority in scale-free networks becomes more obvious as the coupling strength increases. Moreover, the heterogeneity of the network structure profoundly affects the reinforcement efficiency. These findings may provide several useful suggestions for designing more resilient interdependent networks.

Culm blight on Phyllostachys aureosulcata 'Spectabilis' caused by Apiospora locuta-pollinis in China.

Phyllostachys aureosulcata McClure 'Spectabilis' C.D. Chu. et C.S. Chao is predominantly native to subtropical to warm temperate areas and is widely cultivated for landscaping in China (Neményi et al. 2015). In November 2020 (10 - 16 ℃), culm blight symptoms were observed on P. aureosulcata 'Spectabilis' in Wangjiang Tower Park (all kinds of plant areas are about 9.8 ha), Chengdu City (104°09'30.42″ E, 30°63'18.89″ N). Fifty plants were surveyed, and disease incidence was recorded as approximately 30%. Initially, chlorotic necrotic patches appeared on the culms, and gradually the patches became white, expanded to both ends, and encircled the whole culm with black edge and conidiomata, which eventually led to wilt and death. Five samples from different bamboos were collected and one of them were used for morphological observation. Five single conidia isolates were carried out on potato dextrose agar (PDA) at 25±1℃ (Chomnunti et al. 2014). Colonies were initially white and then yellowish in the center with abundant aerial mycelia. On the culm, conidiomata were dry, black, and filamentous. Conidiophores were reduced to conidiogenous cells. Conidiogenous cells were smooth, hyaline, ampulliform to doliiform. Conidia were ellipsoid to globose, dark brown, smooth and aseptate, measuring 5.2 to 9.4 × 4.4 to 7.3 µm, (=8.2 × 6.5µm, n=50). On the PDA medium, conidia were globose to subglobose, olive green to pale brown, and smooth, larger than those from the host in size, measuring 9.0 to 18 × 7.5 to 9.5 µm ( =36.6 × 18.8 µm, n=50). These asexual structures were extremely similar to Apiospora locuta-pollinis (F. Liu & L. Cai) X.G. Tian & Tibpromma (Zhao et al. 2018). DNA was extracted from the representative strain (SICAUCC 22-0036), and the internal transcribed spacer (ITS), translation elongation factor 1-alpha (tef1-α), beta-tubulin (tub2), 28S large subunit rDNA (LSU) were amplified and sequenced with primers ITS1/ITS4 (White et al. 1990), EF1-728F (Carbone & Kohn 1999)/EF2 (O'Donnell et al. 1998), T1 (O'Donnell & Cigelnik 1997)/Bt2b (Glass & Donaldson 1995) and LR0R/LR5 (Rehner & Samuels 1994). The newly generated sequences were deposited in GenBank with accession nos. ON228609 (ITS), ON324018 (tef1-α), ON237657 (tub2), and ON228665 (LSU). Nucleotide blast showed 98.97%, 100% and 99.46% identities with A. locuta-pollinis (LC11683, ex-holotype) (accession nos. MF939595, MF939622, MF939616), and LSU data missing. Phylogenetic analyses using maximum likelihood showed a 92% bootstrap support value in a clade with A. locuta-pollinis (Fig 2). Eight healthy plants (2-year-old) were used for the pathogenicity test. Culms of four healthy bamboos were wounded via sterile double-edged blade and sprayed with conidial suspension (105 conidia/ml) prepared from 4-week-old cultures that were incubated on PDA at 25℃. The other four bamboos were sprayed with sterile distilled water as controls. Inoculated plants were placed in a growth chamber (25℃, 90% relative humidity, 12-h photoperiod). About 60 days later, necrotic patches similar to those observed in the field were found on the inoculated culms, and no symptoms were observed on the controls. The pathogen was reisolated from the diseased culms with identical morphology as previously described. To our knowledge, this is the first report of culm blight on P. aureosulcata 'Spectabilis' caused by A. locuta-pollinis. The risk of this pathogen needs further evaluation, and effective control measures should be taken.

Fusarium proliferatum Associated with Basal Rot Disease of Bambusa pervariabilis × Dendrocalamopsis grandis in China.

Bambusa pervariabilis × Dendrocalamopsis grandis is the main cultivated bamboo species used for ecological construction in the Yangtze River basin. This species has the advantages of easy reproduction, wide adaptability and strong resistance and has high economic, ecological and social benefits (Peng et al. 2020). One area of B. pervariabilis × D. grandis with basal rot disease was discovered in Renshou County, Sichuan Province, China (29°41'N, 104°11'E) in June 2020. The disease occurrence area was 68 hm2 in Renshou County, with an incidence rate of 34.8%, and 5% of the B. pervariabilis × D. grandis with basal rot disease died. The pathogen initially invaded from the first section of the base of the bamboo stalk, appearing as black to yellowish brown strips or lumps of disease spots, and rapidly developed horizontally and vertically, which caused the whole plant to wither in severe cases. Diseased tissues were collected from the base of a 4-year-old bamboo stalk with a sterile blade. 100 pieces (5 × 5 × 2 mm) of diseased tissues were sterilized with 3% NaClO for 30 s and in 75% ethanol for 90 s, rinsed three times with sterile distilled water, dried with sterile surface water on sterile filter paper, plated onto potato dextrose agar amended with streptomycin sulfate (Solarbio, 50 µg/ml), and incubated at 25 °C for 7 days with light. A total of five isolates were obtained, of which four isolates were similar in morphology. Using the method of monospore isolation (Leslie and Summerell 2006) and culturing it on PDA, the fungus produced round colonies with a diameter of approximately 8.4 mm and a surface color ranging from white to purple within 7 days at 25 °C. For identification by typical spores, the fungus was cultured on carnation leaf agar (CLA) medium at 25 °C for 7 days. The microconidia by the isolates BD2002, BD2004, BD2008 and BD2010 cultured on CLA medium were elliptical, ovoid, without septum, and measured 4.56 to 15.53 µm long × 1.36 to 6.98 µm wide (n=100). The macroconidia were rod-shaped or slightly curved, tapering apically with three to five septa, and measured 18.86 to 52.99 × 1.56 to 6.42 µm in size (n=100). According to the morphological characteristics of macroconidia and microconidia, the isolates were identified as Fusarium sp. (Leslie and Summerell 2006). For molecular identification, fungal DNA of isolates BD2002, BD2004, BD2008 and BD2010 was extracted by a fungal genomic DNA extraction kit. Polymerase chain reactions (PCRs) were performed with primers ITS1/ITS4 for the internal transcribed spacer (ITS) rDNA region (White et al. 1990), primers Bt2a/Bt2b for the ß-tubulin (TUB) region (Glass and Donaldson 1995), primers EF1F/EF2R for the translation elongation factor 1α (TEF) region (Carbone et al. 1999), primers 5f2/7cr for the RNA polymerase II genes (RPB2) region (O'Donnell et al. 2010), primers H3-1a/H3-1b for the histone H3 (HIS) region (Jacobs et al. 2010), and primers NMS1/NMS2 for the mitochondrial small subunit (mtSSU) rDNA region (Stenglein et al. 2010). Using BLASTn to search GenBank for ITS, TUB, TEF, RPB2, HIS and mtSSU sequences, all isolates showed the highest similarity with Fusarium proliferatum (Matsushima) Nirenberg. The representative isolate BD2010 showed that ITS had 99.61% similarity to F. proliferatum Z23-28 (FJ648201.1); HIS had 99.57% similarity to F. proliferatum M06A_4G_4 (KX681532.1); and the TUB, TEF, RPB2, and mtSSU sequences showed 99.67%, 99.10%, 99.06%, and 99.57% similarity, respectively, to F. proliferatum ITEM2287 (accession numbers LT841243.1, LT841245.1, LT841252.1, and LT841247.1 in GenBank). The GenBank numbers of the representative isolate BD2010 were ITS, OK325614; TUB, OK377026; TEF, OK377027; RPB2, OK377028; HIS, OK377029; and mtSSU, OK338638. To confirm the pathogenicity, thirty 4-year-old healthy bamboo plants were grown in 30 pots. Each five plants were inoculated with one isolate, and a total of twenty-five plants were inoculated with five isolates. A conidia suspension (1 × 106 conidia/ml) of the fungus was inoculated (100 µl each) into plants that had been acupunctured at the base by a sterile syringe. Five control plants were inoculated only with the same amount of sterile distilled water. The inoculation site was wrapped with wet gauze to maintain moisture. All bamboo plants were watered every seven days. The illumination conditions were 12 h light and 12 h dark. All plants were cultured in a greenhouse at 25-28 °C and 70-80% relative humidity. One month later, twenty plants inoculated with conidial suspensions of BD2002, BD2004, BD2008 and BD2010 showed the same symptoms as those observed in the field, whereas plants inoculated with the other fungus and the control treatment remained asymptomatic. The pathogenicity test was conducted three times, and the experimental results were consistent. Furthermore, the fungi were reisolated from the diseased part and were identified as F. proliferatum by morphological and molecular comparison. To our knowledge, this is the first report of basal rot disease caused by F. proliferatum on B. pervariabilis × D. grandis in China. This research is conducive to laying the foundation for the development of effective control strategies for basal rot disease in this species.

Branch blight of Juglans regia caused by Palmiascoma qujingense in China.

Juglans regia L. is one of the major cultivated walnut species in China for nuts and wood (Pollegioni et al. 2012). In June 2020, branches with blight symptoms were observed in an orchard at Chongzhou City (30°33'34″N, 103°38'35″E). In an orchard of 30 hectares, disease incidence was around 50%. A total of 15 plants were sampled and 40% of their branches were affected by this disease. Firstly, brown and irregular spots appeared, then the spots gradually expanded and encircled the branch, which eventually killed the branch. Five samples of diseased branches from different trees were collected and a single fungal isolate was obtained from each of the five samples using the single ascospore isolation (Chomnunti et al. 2014). Colonies of the five isolates on potato dextrose agar (PDA) were identical that initially appeared white on the top, becoming light to dark brown with age. On the host, ascostroma were black, globose to subglobose, short-papillate, ostiolate, 260 - 410 × 210 - 320 µm (x = 335 × 265 µm, n = 20). Asci were 8-spored, bitunicate, cylindrical, short pedicellate, 55 - 78 × 8 - 12 µm (x = 67.5 × 10 µm, n = 40). Ascospores were 1-septate, fusiform to ellipsoidal, slightly curved, guttulate, 12 - 17 × 3 - 5 µm (x = 14.5 × 4 µm, n = 40). These sexual morphological characteristics are consistent with the Palmiascoma qujingense Phook. & K.D. Hyde (Monkai et al. 2021). Asexual morphs were formed on PDA in incubator after 17 days (25℃, 90% relative humidity, 12-h photoperiod). Conidiomata were black, globose to subglobose, 220 - 300 × 240 - 380 µm (x = 270 × 310 µm, n = 20). Conidia were oblong to ellipsoidal, aseptate and smooth-walled, 3 - 7 × 2 - 4 µm (x = 4.9 × 3 µm, n = 50). The genomic DNA of a representative isolate SICAUCC 21-0013 was extracted, and the internal transcribed spacers (ITS) region, large subunit rDNA (LSU) region, small subunit rDNA (SSU) region, and the largest subunit of RNA polymerase II (rpb2) gene were amplified and sequenced with primers ITS5/ITS4 (White et al. 1990), LR0R/LR5 (Rehner et al. 1994), NS1/NS4 (White et al. 1990), and fRPB2-5F/fRPB2-7cR (Liu et al. 1999), respectively. The sequences were deposited in NCBI with accession numbers MZ983549, MZ959419, MZ951112, and MZ818772, respectively, which showed 100%, 100%, 99.14%, and 99.59% identities with P. qujingense KUMCC 19-0201 (holotype) (accession numbers MT477185, MT477186, MT477183, MT495782respectively). Phylogenetic analysis (maximum likelihood) based on a concatenated dataset showed 93% bootstrap support values with P. qujingense. To verify Koch's postulates, 9 healthy branches from three 1-year-old seedlings were inoculated with conidial suspension (106 conidia/ml) from 4-week-old cultures via pin-prick inoculation (Desai et al. 2019), and the same number of seedlings and branches were inoculated with sterile water as controls. Plants were placed in a greenhouse at 25℃ and 90% RH on a 12-h fluorescent light/dark regime. After 28 days, brown spots were formed on P. qujingense-inoculated branches and similar to those observed in the field, while the controls remained asymptomatic. The pathogen was re-isolated from the lesions and identified by morphology and phylogeny. To our knowledge, this is the first report of P. qujingense causing branch blight on J. regia in the world. This disease potentially impacts the growth and yield of J. regia, and control measures should be made.

Trunk canker of Juglans sigillata caused by Lasiodiplodia pseudotheobromae in China.

Iron walnut (Juglans sigillata Dode) is a temperate deciduous tree indigenous to China. It is mainly distributed in southwestern China, and valued for its wood and nuts (Feng et al. 2018). In September 2020, symptoms of canker on J. sigillata were observed in an orchard measuring 2 hectares located in Chongzhou City, Sichuan Province (31°5' 25″N, 105°27'36″E, 365 m altitude). Twenty percent of plants showed canker symptoms during the 50 surveyed plants. The infected trunk showed necrotic lesions with black pycnidia, that led to necrosis of branches and death of the whole plant in severe cases (Fig. 1). Six specimens from different diseased plants were collected for pathogen isolation and morphological observation. Pure cultures were obtained from single conidium on potato-dextrose agar (PDA) media according to the method described by Chomnunti (Chomnunti et al. 2014). Colonies grew fast and reached 3 cm after 5 days. The aerial mycelium was abundant, which was initially white and then grayish. Conidiomata on the host were measured 160-280 µm × 140-190 µm (average: 220 × 165 µm, n = 20), stromatic, uniloculate, dark brown to black, immersed, and erumpent when mature. Pycnidial walls 32-58 µm wide, were composed of 5-7 layers of brown to dark brown cells. Conidia were hyaline, and ellipsoidal with rounded apex and base, widest at the middle, thick-walled, and unicellular, with a size 21.5-31 µm × 11.5-15.7 µm (average: 27 × 13.5 µm, n = 50). Morphological characteristics fit the description of Lasiodiplodia pseudotheobromae A.J.L. Phillips, A. Alves & Crous (Aives et al. 2008). The internal transcribed spacers (ITS), 18S small subunit rRNA (SSU), 28S large subunit rDNA (LSU), translation elongation factor 1-alpha (tef1-α), and beta-tubulin (tub2) were amplified by polymerase chain reaction and sequenced with primers ITS1/ITS4, NS1/NS4, LR0R/LR5, EF1-728F/EF1-986R and Bt2a/Bt2b, respectively (Li et al. 2018). The sequences of the representative isolate (SICAUCC 22-0079) were deposited in NCBI with accession numbers ON090365 (ITS), ON090406 (SSU), ON090418 (LSU), ON112377 (tef1-α), and ON112378 (tub2), respectively. Nucleotide blast showed 100% similarity of all the analyzed and NCBI submitted isolates with L. pseudotheobromae (CBS116459; holotype) (accession numbers EF622077, EU673199, EU673256, EF622057, EU673111). Phylogenetic analyses based on a combined dataset showed 100% bootstrap support values in a clade with L. pseudotheobromae complexes (Fig. 2). Based on morphological and molecular analyses, the fungal pathogen was identified as L. pseudotheobromae. To conduct Koch's postulates, four 2-year-old healthy plants of J. sigillata were inoculated with 10 µL spore suspension (105 conidia/mL) onto the wounded sites via sterile pin. As control, four healthy plants were treated with sterile distilled water. The inoculated and untreated plants were placed in a growth chamber at 25°C with relative humidity >90% and 12-h photoperiod. Trunk canker symptoms appeared on inoculated plants after 15-20 days, and the pathogen was re-isolated and the controls were symptomless, confirming Koch's postulates. L. pseudotheobromae is widely distributed in various plants all over the world, usually as a pathogen associated with damping-off, wilt, die-back, root rot, collar rot, witches' brooms, or fruit rots (Zhao et al. 2010). To our knowledge, this is the first report of trunk canker on J. sigillata caused by L. pseudotheobromae in China. Trunk canker caused by L. pseudotheobromae is becoming a potential threat to walnut production, and some necessary measures for integrated management should be made.

Branch blight of Juglans sigillata caused by Juglanconis appendiculata in China.

Juglans sigillata Dode, an endemic walnut species native in southwest China, is mainly used as nuts in Sichuan Province (Jin et al., 2019). In May 2021, symptoms of branches blight were observed in an orchard measuring 10 hectares located in Mianyang City, Sichuan Province (31°5' 25″N, 105°27'36″E, 365 m above sea level). About 40% of plants were diseased in the quadrat consisting of twenty walnut trees, and 20% of branches were dead on each affected tree. Initially, light brown spots appeared; then, the spots expanded to surround the whole branches; finally, the branches changed from brown to reddish-brown and died. Four symptomatic branches were sampled randomly from different trees. Next, four fungal isolates were obtained from the acervuli of each branch using the single-conidium isolation (Chomnunti et al. 2014) and cultured on potato dextrose agar (PDA). The Petri dishes were placed in an incubator and cultured at 25 °C under a 12-h photoperiod. Colonies were initially white with thin aerial mycelia and gradually turned dark grey with irregular margins. Conidiomata were acervular, black and scattered, with a diameter of 0.3 - 0.7 mm. Conidiophores were narrowly cylindrical, simple or branched at the base, 30 - 43 × 3 - 8 µm (x = 36.5 × 5.5 µm, n = 40). Conidiogenous cells were annellidic with distinct annellations. Conidia were unicellular, brown when mature, narrowly ellipsoid with gelatinous sheaths and truncate scars at the base, 17 - 32 × 7 - 12 µm (x = 27 × 9 µm, n = 40). The genomic DNA of a representative isolate SICAUCC 22-0064 was extracted, and the internal transcribed spacer (ITS) region, guanine nucleotide-binding protein subunit beta gene (ms204), translation elongation factor 1-alpha (tef1-α), and partial sequences of ß-tubulin (tub2) were amplified by polymerase chain reaction and sequenced with primers V9G/LR5 (de Hoog & van den Ende 1998), MS-E1F1/MS-E5R1 (Walker et al. 2012), EF1-728F (Carbone & Kohn 1999)/TEF1LLErev (Jaklitsch et al. 2005), and T1/BtHV2r (Voglmayr et al. 2017), respectively. The sequences of ITS, ms204, tef1-α, and tub2 were deposited in NCBI with accession numbers ON000068, ON112376, ON112374, and ON112375, respectively. With the consideration of the sequence lack of ms204 and tub2 in the ex-type strain (D96) of Juglanconis appendiculata Voglmayr & Jaklitsch, the isolate D140 was used for nucleotide blast. The results showed 99.68%, 100%, 100%, and 100% identities of ITS, ms204, tef1-α, and tub2 with D140 (accession numbers KY427138, KY427157, KY427207, KY427226). Phylogenetic analysis based on a combined dataset showed 100% bootstrap with J. appendiculata, and the morphology was consistent with the asexual stage of J. appendiculata (Voglmayr et al., 2017). To verify Koch's postulates, five branches wounded by pin-prick were sprayed with conidial suspension (1 × 105 conidia/mL) in each plant, and three repetitions were performed on healthy 2-year-old potted plants. The same number of branches were sprayed with sterile distilled water as controls. The plants were placed in a greenhouse at 25 ℃ under 90% relative humidity and a 12-h fluorescent light/dark regime. After five weeks, all the inoculated branches showed brown necrosis similar to that observed in the field, and no symptoms occurred on the controls. The pathogens were re-isolated from the necrotic lesions and identified by morphology and phylogeny. J. appendiculata has been reported on Juglans nigra and J. regia in Austria, France, Spain and Greece (Farr & Rossman 2022). This paper is the first report of branch blight on Juglans sigillata caused by J. appendiculata in China. This result may develop the understanding of walnut diseases and lay a foundation for further management.

Leaf spot on Alocasia macrorrhizos caused by Fusarium asiaticum in Sichuan, China.

Alocasia macrorrhizos (Giant elephant's ear), a perennial herb in the Araceae family, is native to South Asia and the Asia-Pacific (Takano, et al. 2012). It is cultivated as a medicinal and ornamental plant, and has a considerable economic importance in China. In September 2020, a severe infection of unknown leaf spot disease was observed on these plants at the Sichuan Agricultural University, Sichuan, China. The leaf spots first appeared as yellow dots. As these lesions expanded, they became circular to oval and light brown with darker brown edges. Around the lesions, the leaf tissue was chlorotic, thereby creating a yellow halo. When the infection became severe, spots merged into larger irregular lesions. Eventually, the diseased leaves senesced and dried. To identify the pathogen, five leaf samples of diseased plants were collected, and symptomatic tissues were surface-disinfected with 75% ethanol for 30 s followed by 3% NaCl solution for 30 s. Samples were rinsed three times in sterilized water, placed on potato dextrose agar (PDA), and incubated at 25°C ± 1°C in the dark. The colony grown on PDA was white (3 days), the center was brown (5 days), turned pink to dark red (8 days) with fluffy aerial mycelium and pigmentation with age. Ten pure cultures were inoculated into carnation leaf agar (CLA) medium and incubated at 25°C in an incubator (12 h for one light-dark cycle). In CLA medium, pathogen produced hyaline, sickle-shaped, macroconidia with 3 to 5 septa, and an average size of 30 to 50 × 4 to 5 µm (n = 30) macroconidia but no microconidia in 10 days. Chlamydospores were spherical to subspherical (5.4 to 13.8 µm). Morphological characteristics of the all isolates were consistent with the description of the Fusarium asiaticum (Leslie and Summerell 2006). To validate this identification, RNA polymerase II (RPB2) (Liu et al. 1999), translation elongation factor (EF-1) (Geiser et al. 2004), and ß-tubulin (TUB2) gene region of five isolates were amplified and sequenced (O' Donnell et al. 2015; White et al. 1990). The sequence of one representative isolate (ZL10) sequence was submitted to GenBank (ON215729, ON215730, and ON215731). The NCBI BLAST identified the top hits, 100%, 100%, and 99.87% for RPB2, EF, and TUB gene sequences, respectively, all indicating to Fusarium asiaticum. Pairwise matched of RPB2 and EF genes by MycoBank Fusarium MSIL showed the top hit rate of 100% for F. asiaticum (MH582120 and MH582249). For Koch's postulate and pathogenicity test, spore suspensions (1 × 10^7 conidia/ml) collected from PDA and CLA cultures with 0.05% Tween 80 buffer were used to inoculate with a spray bottle on leaves of a one year old A. macrorrhizos plants. Two leaves of each plant (20 pots in total) were inoculated with the spore suspension (approximately 2000 µl per leaf). An equal number of control leaves were applied with water and 0.05% Tween 80 buffer. Twenty days later, the inoculated plants showed similar symptoms to those of the original diseased plants while the controls remained asymptomatic. Fusarium asiaticum was reisolated from the infected leaves and confirmed using morphological characteristics and DNA sequence analysis. The pathogenicity test was repeated three times with similar results. This first report raises awareness of a new leaf spot disease infecting a commercial A. macrorrhizos in China. It provides an insight for a need of systematic survey identifying current spread, disease origin, and ultimately developing disease management strategies. Funding: Funding was provided by Sichuan Agricultural University Subject Dual Support Program (Grant No. 2121993055). Funding was provided by Deyang Science and Technology Bureau (Sichuan Province) for key R&D projects in agriculture and rural areas (Grant No. 2021NZ048). Funding was provided by the Sichuan Provincial Department of science and technology for the Sichuan Provincial Science and technology project for connecting and Promoting Rural Revitalization (Grant No, 2022ZHXC0007) References： Geiser, D. M., et al. 2004. Eur. J. Plant Pathol. 110:473. https://doi.org/10.1023/B:EJPP.0000032386.75915.a0 Crossref, ISI, Google Scholar Leslie, J. F., and Summerall, B. A., eds. 2006. Page 176 in The Fusarium Laboratory Manual. Blackwell Publishing, Ames, IA. https://doi.org/10.1002/9780470278376 Liu, Y. J., et al. 1999. Mol. Biol. Evol. 16:1799. https://doi.org/10.1093/oxfordjournals.molbev.a026092 O'Donnell, K., and Cigelnik, E. 1997. Mol. Phylogenet. Evol. 7:103. https://doi.org/10.1006/mpev.1996.0376 Takano K T, et al. 2012, Plant Bio., 14(4). https://doi.org/10.1111/j.1438-8677.2011.00541.x.

Longitudinal Predictive Control for Vehicle-Following Collision Avoidance in Autonomous Driving Considering Distance and Acceleration Compensation.

In response to the widespread adoption of vehicle-following systems in autonomous applications, the demand for collision warning to enable safer functionalities is increasing. This study provides an approach for automated vehicle guidance to follow the preceding vehicles longitudinally and puts emphasis on the performance of collision avoidance. The safety distance model is established, which contains a distance compensation algorithm to deal with the special case on curved roads. By introducing the algorithm of velocity and distance prediction, the collision risks are detected and measured in real time. The objective function is established based on optimal control theory to solve the desired following acceleration. The control system designed with the method of proportion integration differentiation combines throttle percentage and brake pressure as outputs to compensate acceleration. In the Carsim and Simulink co-simulation platform, the control system for longitudinal collision avoidance is simulated and analysed for four typical working conditions: the preceding vehicle drives at a constant speed on straight and curved roads, while the preceding vehicle drives at various speeds on straight and curved roads. The results validate the feasibility and effectiveness of the proposed method, which can be used for the longitudinal control of vehicle-following active collision avoidance.

Cloning and Characterization of Two Novel PR4 Genes from Picea asperata.

Pathogenesis-related (PR) proteins are important in plant pathogenic resistance and comprise 17 families, including the PR4 family, with antifungal and anti-pathogenic functions. PR4 proteins contain a C-terminal Barwin domain and are divided into Classes I and II based on the presence of an N-terminal chitin-binding domain (CBD). This study is the first to isolate two PR4 genes, PaPR4-a and PaPR4-b, from Picea asperata, encoding PaPR4-a and PaPR4-b, respectively. Sequence analyses suggested that they were Class II proteins, owing to the presence of an N-terminal signal peptide and a C-terminal Barwin domain, but no CBD. Tertiary structure analyses using the Barwin-like protein of papaya as a template revealed structural similarity, and therefore, functional similarity between the proteins. Predictive results revealed an N-terminal transmembrane domain, and subcellular localization studies confirmed its location on cell membrane and nuclei. Real-time quantitative PCR (RT-qPCR) demonstrated that PaPR4-a and PaPR4-b expression levels were upregulated following infection with Lophodermium piceae. Additionally, PaPR4-a and PaPR4-b were induced in Escherichia coli, where the recombinant proteins existed in inclusion bodies. The renatured purified proteins showed antifungal activity. Furthermore, transgenic tobacco overexpressing PaPR4-a and PaPR4-b exhibited improved resistance to fungal infection. The study can provide a basis for further molecular mechanistic insights into PR4-induced defense responses.

Gradient-based elephant herding optimization for cluster analysis.

Clustering analysis is essential for obtaining valuable information from a predetermined dataset. However, traditional clustering methods suffer from falling into local optima and an overdependence on the quality of the initial solution. Given these defects, a novel clustering method called gradient-based elephant herding optimization for cluster analysis (GBEHO) is proposed. A well-defined set of heuristics is introduced to select the initial centroids instead of selecting random initial points. Specifically, the elephant optimization algorithm (EHO) is combined with the gradient-based algorithm GBO for assigning initial cluster centers across the search space. Second, to overcome the imbalance between the original EHO exploration and exploitation, the initialized population is improved by introducing Gaussian chaos mapping. In addition, two operators, i.e., random wandering and variation operators, are set to adjust the location update strategy of the agents. Nine datasets from synthetic and real-world datasets are adopted to evaluate the effectiveness of the proposed algorithm and the other metaheuristic algorithms. The results show that the proposed algorithm ranks first among the 10 algorithms. It is also extensively compared with state-of-the-art techniques, and four evaluation criteria of accuracy rate, specificity, detection rate, and F-measure are used. The obtained results clearly indicate the excellent performance of GBEHO, while the stability is also more prominent.

Gadd45b is a novel mediator of depression-like behaviors and neuroinflammation after cerebral ischemia.

BACKGROUND: Poststroke depression (PSD) is an important consequence after stroke, with a negative impact on stroke outcome. Recent evidence points to a modulatory role of Growth arrest and DNA-damage-inducible protein 45 beta (Gadd45b) in depression. Herein, we evaluated the antidepressant efficacy and mechanism underlying the potent therapeutic effects of Gadd45b after cerebral ischemia. METHODS: Adult male Sprague-Dawley rats were subjected to cerebral ischemia by permanent middle cerebral artery occlusion (MCAO). The sucrose preference test (SPT), forced swim test (FST), and tail suspension test (TST) were performed after completing MCAO to study the antidepressant-like effects. The expression of brain-derived neurotrophic factor (BDNF) and neuroinflammation were determined in the hippocampus. RESULTS: We showed that Gadd45b knockdown induced depression-like behaviors after cerebral ischemia, including increased immobility time in the FST and TST and reduced sucrose preference. Gadd45b knockdown enhanced the expression of pro-inflammatory cytokines IL-6 and TNF-α, accompanying with decreased protein levels of BDNF in the hippocampus. Moreover, the levels of phosphorylated ERK and CREB, which have been implicated in events downstream of BDNF signaling, were also decreased after cerebral ischemia. CONCLUSION: Hence, the results showed that Gadd45b is a promising drug candidate for treating PSD and possibly other nervous system diseases associated with neuroinflammation. Gadd45b may have therapeutic potential for PSD through BDNF-ERK-CREB pathway and neuroinflammation.