First report of Lasiodipilodia theobromae Causing leaf spot of Agave sisalana in GuangXi, China.

Agave sisalana, as an excellent fiber producing plant, is mainly planted in Guangxi Province, China. In November 2023, a foliar disease occured on A. sisalana at Liangjiang Town (108.3593 W, 23.4723 N), Wuming District, Nanning in GuangXi, China. Approximately 50 to 60% of the plants (n=200) had obvious leaf spots on more than 70% of the leaves. On the leaves of sisal, circular or irregularly shaped yellow brown spots can be seen, sunken, with no halo on the edges. As time goes on, the lesion gradually expands to the entire blade of the sword (Figure 1A, 1B). To identify the disease etiology, ten agave leaves were collected from GuangXi. Symptomatic midribs were cut into 3×3 mm pieces, surface sterilized with 75 % ethanol for 20 s, rinsed with sterilized distilled water three times, air dried on sterile filter paper, plated on photo dextrose agar (PDA) medium, and incubated at 28 ℃ in the dark. Five isolates (JM01, JM02, JM03, JM05, JM06) with similar morphology were obtained. Colonies on PDA medium were white to grayish-white with atrial mycelia growing initially upward and then forming clusters (Figure 1E). After five days, mycelia turned grayish black. Immature conidia were initially hyaline, aseptate, and ellipsoid. Mature conidia were dark brown, one septate, longitudinal striate, and 22.1 to 26.3×10.2 to 14.9 µm (Figure 1F). Morphologically , the isolates were identified as Lasiodiplodia theobromae (Alves et al. 2008). For molecular identification, genome DNA of five representative isolate was extracted using the Fungi Genomic DNA Purification kit. The internal transcribed spacer (ITS) region of rDNA and translation elongation factor 1-alpha (TEF-1α) and ß-tublin (TUB) gene were amplified with primer pairs ITS1/ITS4 (White et al. 1990), EF1-728F/EF1-986R (Carbone and Kohn 1999), and Bt2a/Bt2b (Glass and Donaldson 1995), respectively, and sequenced. The ITS (PP209594), TEF-1α (PP234629), and TUB (PP234628) sequences of representative isolate JM01 were deposited in GeneBank. BLAST searches showed >99% nucleotide identity to sequences of L. theobromae (ITS, 99.26% to NR111174; TEF-1α, 99.69% to MM840490; TUB, 98.92% to MN172230). Phylogenetic analysis using maximum likelihood based on the combined ITS, TEF-1α, and TUB sequences of the isolates and reference sequences of Lasiodiplodias spp. from GenBank indicated the isolates obtained in this study formed a clade strongly supported based on bootstrap values to the ex-type isolate CBS164.96 sequences of L.theobromae (Figure 2). To test pathogenicity, JM01 was tested by inoculation leaves of one year old agave plants, the epidermis at the inoculation site, 10, 15 and 20 cm below to the crown, was wiped with a 75% alcohol cotton ball, washed three times with sterile water, and punctured (5 mm diameter) with a sterile inoculation needle. A 5 mm block of each isolate cultured on PDA for 3 days was attached to the inoculation site. Controls were inoculated with sterile PDA. The inoculation area was covered with plastic wrap. All plants were kept in a controlled greenhouse at 27℃, 80% relative humidity, and natural daylight, and watered weekly. Each treatment was repeated three times. Remove the block one day later. Three days after inoculation, all inoculated had typical symptoms,but control were healthy (Figure 1C, 1D). Fungal isolates were only recovered from symptomatic stems and were morphologically identical to L. theobromae, completing Koch's postulates. L. Theobromae has been reported as the cause of leaf rot on A. angustifolia in Mexico (Reyes-García et al. 2023). To our knowledge, this is the first report of L. theobromae causing leaf spot on A. sisalana in GuangXi, China. L. theobromae is primarily a plant pathogen that causes rotting and dieback in fruits and plants in tropical and subtropical regions (Puttanna 1967). This study is useful to focus on management strategies for leaf rot disease by L. theobromae of A. sisalana.

First Report of Nigrospora hainanensis Causing Leaf Blight on Brachiaria Griseb in China.

Brachiaria Griseb is an important gramineous forage grown in tropical regions, and also a main grass species uses to restore grasslands in tropical and subtropical regions of China. In August 2022, symptoms of leaf blight were observed on nearly 30% of the Brachiaria forage grass in the base of the Chinese Academy of Tropical Agricultural Sciences, Hainan, China. Symptomatic leaves initially exhibited small, reddish-brown, round or oval spots on their tips, subsequently expanding in size along the leaf margin, and gradually becoming wilted and dry. Twenty leaves showing typical symptoms were randomly collected and pieces (5×5 mm) from the junction of diseased and healthy region were cut, sterilized with 75% alcohol for 30 s, followed by 5% sodium hypochlorite for 30 s. Rinsed three times with sterile water and dried with sterile filter paper. Leaf pieces were placed on potato dextrose agar (PDA) and incubated at 28℃. The colonies were white on the surface and gray on the reverse side. The conidiogenous cells were monoblastic, hyaline, globose or ampulliform, and 6 to 8.7(13.1) ×5 to 7.2 (9) m (n=200). Conidia is single celled, smooth, black, spherical, or ellipsoidal, and (11)13 to 16.5 × (8.2) 10.3 to16.1 m (n=100). Setae were not observed. The morphological characteristics of the isolates were consistent with Nigrospora species. A representative isolate (LNH-5) was selected for genomic DNA extraction. Sequences of the transcribed spacer region of rDNA (ITS), partial translation elongation factor (TEF1), and beta-tubulin fragment (TUB) were amplified using primer pairs ITS1/ITS4(White et al. 1990), EF-728F and EF-986R (Carbone et al. 1999) and Bt2a and Bt2b (Glass et al. 1995), respectively. The sequences of ITS (OQ473493), TEF1 (OQ506059) and TUB gene (OQ506055) were submitted to GenBank. They were 99 to 100% identical to the Nigrospora hainanensis ITS(OM283581.1)(538 out of 519 bp),TEF1(YK019415.1)(274 out of 276 bp),and TUB (OK086377.1)(405 out of 405 bp) sequences. The phylogenetic maximum likelihood analysis using the combined ITS, TEF1 and TUB sequences indicated that the isolate was part of the N. hainanensis clade (100% bootstrap value) that also contained the type isolate LC6979 of this species. Pathogenicity was tested on 15 healthy Brachiaria plants. Fungal conidia were harvested by flooding two-week-old single conidial cultures with sterile water, centrifuging, and adjusting the concentration to 107 spores/mL. Then 10 µL of conidial suspension was dropped onto the surfaces of leaves wounded with a sterile needle. Sterile distilled water was used for control treatment. The test was repeated three times. After inoculation, the plants were kept at 90~100% relative humidity at 25 to 28°C in a greenhouse for two weeks, and monitored daily for lesion development. Seven days post inoculation, all the inoculated leaves presented symptoms similar to those observed under natural conditions, while the control leaves showed no symptoms. The fungus was re-isolated from the diseased tissues by the single spore isolation method (Choi et al. 1999) to complete Koch's postulates. This pathogen has been reported on sugarcane in China (Raza et al., 2019; Zheng et al., 2022). To our knowledge, this is the first report of N. hainanensis causing leaf blight on Brachiaria plants in China.

First Report of Paramyrothecium breviseta Causing Leaf Spot Disease of Coffea canephora in China.

Coffee is a tropical plant with two widely cultivated species, namely Coffea arabica and Coffea canephora. A leaf spot disease causing brownish and necrotic lesions was broken out on the C. canephora coffee seedlings in a nursery in Ruili County, Yunnan Province, China, during 2018 to 2019. The incidence of the disease was 15% ~ 20%. Ten diseased leaf samples from five diseased plants were collected for pathogen isolation by tissue separation method. Leaf pieces were cut from the margin of the necrotic lesions (4 × 6 mm), surface-sterilized for 30 s in 75% ethanol, followed by 0.1% arsenic mercury solution for 15 s, then washed 3~4 times with sterilized distilled water and transferred onto potato dextrose agar (PDA) medium in petri plates. Four morphologically similar isolates were obtained from lesions and cultivated on PDA at 25°C. Initial colonies of isolates were round, neat edge, white, floccose mycelium and developed dark green-to-black concentric rings that were sporodochia bearing viscid spore masses after 5~7 days. Conidia were acetates, hyaline and cylindrical with both rounded ends and 4.8 to 6.4 µm long × 1.6 to 2.6 µm wide. Koch's test were conducted on three healthy plants leaves of original source variety C. canephora No.2 and C.arabica Catimor CIFC7963 (control plants) with spore suspension (1 × 106/mL), respectively. Meanwhile, equal numbers of healthy plants were inoculated with water as controls. After inoculation, the plants were transferred into an incubator at 25℃ with saturated humidity. After 10 days of inoculation, all the tested plants presented similar typical symptoms with the diseased leaves under natural conditions; whereas the controls remained healthy. Koch's postulates were performed by re-isolating the fungus from the inoculated leaves and verifying its colony and morphological characters. Two single spore isolates cultured on PDA medium were selected for DNA extraction. The ribosomal internal transcribed spacer (ITS) was PCR amplified by using primers ITS1 and ITS4 (White et al., 1990), ß-tubulin gene by Bt2a and Bt2b (Glass and Donaldson, 1995), the RNA polymerase II second largest subunit (rpb2) by RPB2-5F2 and RPB2-7cR (O'Donnell et al, 2007), calmodulin (cmda) gene by CAL-228F and CAL2Rd (Groenewald et al., 2013). The sequences of ITS (MT853067 ~ MT853068), ß-tubulin (MT897899 ~ MT897900), rpb2 (MW256264~ MW286265) and cmda (MT897897~ MT897898) were deposited in GenBank databases. BLAST analysis revealed that the representative isolates sequences shared 99.31%~99.65% similarities to the ITS sequence of Paramyrothecium breviseta (Accession Nos. NR_155670.1), 99.43% similarities to the ß-tubulin sequence of P. breviseta (Accession Nos. KU846406.1), 98.98% similarities to the rpb2 sequence of P. breviseta (Accession Nos. KU846351.1), and 98.54%~98.71% similarities to the cmda sequence of P. breviseta (Accession Nos. KU846262.1). As it shown in the phylogenetic tree derived from combined ITS, ß-tubulin, rpb2, and cmda gene sequences, the two representative isolates were clustered together with P. breviseta CBS 544.75 with 98% strong bootstrap support, which confirmed that P. breviseta is the causal agent of leaf spot of Coffea canephora. To our knowledge, this is the first report of a leaf spot disease caused by P. breviseta on C. canephora in China, which raised the caution that P. breviseta is also pathogenic to Coffea Arabica.

Evaluation of genetic diversity within asparagus germplasm based on morphological traits and ISSR markers.

Asparagus officinalis L. is a dioecious perennial plant globally known for its fine flavor and high nutritional value. An evaluation of genetic diversity in 46 asparagus accessions was carried out based on morphological and inter-simple sequence repeat (ISSR) markers. The result show that the coefficient of variation for 20 morphological characteristics is between 12.45 and 62.22%. Factor analysis revealed that nine factors explained 83.37% of the total variance. At Euclidean distance of 135.7, 46 accessions were divided into two clusters. Genetic similarity coefficient (GSC) based on ISSR data ranged from 0.60 to 0.97, suggesting a relatively abundant genetic base. Furthermore, the 46 asparagus accessions could also be grouped into three major clusters at a GSC of 0.74. And there is no significant relation between the two marker systems using the Mantel test. Clustering based on morphological traits compared with that based on ISSR data was not consistent, however, some common groupings were observed between two dendrograms. Therefore the results elucidated asparagus germplasm genetic background and determined hybrid parents, which will facilitate optimal application of asparagus germplasm resources and provide additional data for genetic improvement.

Transcription factor WRKY30 mediates resistance to Cucumber mosaic virus in Arabidopsis.

WRKY transcription factors are key regulators in regulating abiotic or biotic stress response in Arabidopsis. Previous studies showed that WRKY30 expression was induced by oxidative stress treatment, fungal elicitor, SA and ABA. However, functions of WRKY30 on viral defense are not well studied. Here, we found that Arabidopsis WRKY DNA binding protein 30 (WRKY30) plays essential roles in regulating Cucumber mosaic virus (CMV) resistance. The expression of WRKY30 was induced by CMV infection and wrky30 mutant displayed more susceptibility (including higher oxidative damages, induced reactive oxygen species synthesis and more PSII photochemistry compromise), while WRKY30 overexpression plants (WRKY30OX) exhibited more resistance to CMV infection. Moreover BRs-induced CMV tolerance is partly dependent on WRKY30. And WRKY30 expression increased after BL treatment. All these demonstrated that WRKY30 works as a positive regulator in plant CMV resistance process.

Isolation and characterization of a cryptogein-like gene from drought and salt-treated Alternanthera philoxeroides roots.

Alligator weed, Alternanthera philoxeroides (Mart.) Grisb, is an amphibious plant with long thick fleshy roots that develop from adventitious roots under drought conditions. To clone differentially-expressed genes from the roots of A. philoxeroides we applied both mRNA differential display and rapid amplification of cDNA ends techniques. A cryptogein-like gene of A. philoxeroides, designated as ApCL, was cloned. On the basis of semi-quantitative RT-PCR analysis results, we demonstrated that the ApCL gene was upregulated under drought and salt stress conditions. After ApCL was transferred to Pichia pastoris GS115 and its resistance to drought and salt then increased by >100 %. Therefore, the ApCL gene of A. philoxeroides was likely involved in drought and salt tolerance responses.

Biotransformation of steroidal saponins in sisal (Agave sisalana Perrine) to tigogenin by a newly isolated strain from a karst area of Guilin, China.

A rod-shaped bacterium was isolated from the soil in a karst area of Guilin, China and its biotransformation of steroidal saponins in sisal (Agave sisalana Perrine) to tigogenin was presented for the first time. A total of 22 strains for the degradation of steroidal saponins in sisal were isolated from 48 soil samples, and the isolated rod-shaped, bacterial strain ZG-21 was used for the production of tigogenin due to its highest degradation efficiency of steroidal saponins in sisal. The parameters affecting biotransformation by strain ZG-21 were optimized. Under the optimized conditions of temperature (30 °C), pH (6), time (5 days) and substrate concentration (5 mg/mL), a maximum tigogenin yield of 26.7 mg/g was achieved. Compared with the conventional method of acid hydrolysis, the biotransformation method provided a clean and eco-friendly alternative for the production of tigogenin.

Characterization and Fungicide Sensitivity of Phaeosphaeriopsis obtusispora That Causes Marginal Leaf Blight in Agave hybrid H.11648.

Sisal is an important tropical cash crop in southern China. Unfortunately, it is threatened by various diseases. In 2022, a new disease tentatively named marginal leaf blight disease (MLBD) was first observed in sisal fields across Guangxi and Guangdong provinces, with an incidence rate ranging from 13% to 30%. In this work, to isolate and identify the pathogens causing MLBD, sisal leaves exhibiting the typical MLBD symptoms were collected, and nine strains were obtained. Pathogenicity tests, morphological observations, and phylogenetic analyses confirmed that two strains, namely 22GX1-3 and 22GD1-4, identified as Phaeosphaeriopsis obtusispora, were the causative pathogens of MLBD. Further investigations into the biological characteristics of P. obtusispora showed that its mycelia exhibited optimal growth on PDA medium, with the most favourable temperature and pH being 25 °C and 7.0, respectively. The mycelia could grow in temperatures ranging from 10 °C to 32 °C but ceased at 35 °C. Lactose and yeast extract powder were also identified as the optimal carbon and nitrogen sources, respectively. Additionally, the effectiveness of various control agents was assessed on a single strain, 22GX1-3. Among the twelve fungicides tested, difenoconazole was proven the most effective, with an EC50 value of 0.5045 µg/mL. To our knowledge, this is the first report for sisal MLBD caused by P. obtusispora. Our results provide crucial pieces of information for the development of effective management strategies to control sisal MLBD caused by P. obtusispora.

Full-length agave transcriptome reveals candidate glycosyltransferase genes involved in hemicellulose biosynthesis.

Agave species are typical crassulacean acid metabolism (CAM) plants commonly cultivated to produce beverages, fibers, and medicines. To date, few studies have examined hemicellulose biosynthesis in Agave H11648, which is the primary cultivar used for fiber production. We conducted PacBio sequencing to obtain full-length transcriptome of five agave tissues: leaves, shoots, roots, flowers, and fruits. A total of 41,807 genes were generated, with a mean length of 2394 bp and an annotation rate of 97.12 % using public databases. We identified 42 glycosyltransferase genes related to hemicellulose biosynthesis, including mixed-linkage glucan (1), glucomannan (5), xyloglucan (16), and xylan (20). Their expression patterns were examined during leaf development and fungal infection, together with hemicellulose content. The results revealed four candidate glycosyltransferase genes involved in xyloglucan and xylan biosynthesis, including glucan synthase (CSLC), xylosyl transferase (XXT), xylan glucuronyltransferase (GUX), and xylan α-1,3-arabinosyltransferase (XAT). These genes can be potential targets for manipulating xyloglucan and xylan traits in agaves, and can also be used as candidate enzymatic tools for enzyme engineering. We have provided the first full-length transcriptome of agave, which will be a useful resource for gene identification and characterization in agave species. We also elucidated the hemicellulose biosynthesis machinery, which will benefit future studies on hemicellulose traits in agave.

A Molecular Switch-Integrated Nanoplatform Enables Photo-Unlocked Antibacterial Drug Delivery for Synergistic Abscess Therapy.

Drug delivery systems (DDSs) capable of sequential multistage drug release are urgently needed for antibacterial applications. Herein, a molecular switch-integrated, photo-responsive nanoplatform is reported based on hollow mesoporous silica nanospheres (HMSN) loaded with silver nanoparticles (Ag NPs), vancomycin (Van), and hemin (HAVH) for bacteria elimination and abscess therapy. Upon near-infrared (NIR) light irradiation, the molecular switch, hemin, can effuse from the mesopores of HMSN, triggering the release of pre-loaded Ag+ and Van, which enables photothermal-modulated drug release and synergistic photothermal-chemo therapy (PTT-CHT). The HAVH_NIR irreversibly disrupts the bacterial cell membrane, facilitating the penetration of Ag+ and Van. It is found that these compounds restrain the transcription and translation of ribosomes and lead to rapid bacterial death. Furthermore, hemin can effectively inhibit excessive inflammatory responses associated with the treatment, promoting accelerated wound healing in a murine abscess model. This work presents a new strategy for antibacterial drug delivery with high controllability and extendibility, which may benefit the development of smart multifunctional nanomedicine for diseases not limited to bacterial infections.

Transcriptome Sequencing of Agave amaniensis Reveals Shoot-Related Expression Patterns of Expansin A Genes in Agave.

Agave species are widely planted for fiber production. However, the molecular basis of agave fiber development has not been well understood. In this study, we performed a transcriptomic analysis in A. amaniensi, a well-known variety with high-quality fiber production. Approximately 43.87 million clean reads were obtained using Illumina sequencing. The de novo assembly produced 66,746 unigrams, 54% of which were annotated in a public database. In the Nr database, 21,490 unigenes of A. amaniensis were shown to be most closely related to Asparagus officinalis. Nine expansin A orthologs with full coding regions were obtained, which were named EXP1a, EXP1b, EXP2, EXP3, EXP4a, EXP4b, EXP11, EXP12, and EXP13. The maximum likelihood phylogenetic tree revealed the species-specific expansion of expansin genes in Arabidopsis, rice and agave. The expression analysis suggested the negative correlation between the expression of expansin genes and the leaf growth rate, except AhEXP11. Moreover, expansin genes were differentially affected by abiotic and biotic stresses. Notably, AhEXP2 expression level was highly upgraded after the infection of Phytophthora nicotiana. Nutrient deficiency also influent expansin genes expression. Together, our research will benefit future studies related to fiber development, disease resistance and nutrient usage in agave.

Exploring cadmium stress responses in sisal roots: Insights from biochemical and transcriptome analysis.

Sisal is a leaf fiber crop with a high integrated value and a wide range of uses in the application of soil remediation of heavy metal contamination. This study provides a preliminary understanding of how sisal responds to Cd stress and presents a theoretical basis for exploring the potential of sisal in the remediation of Cd-contaminated soils. In this work, the activities of the antioxidant enzymes (SOD, POD, and CAT) of sisal were measured by hydroponics with the addition of CdCl2·2.5H2O and different concentrations of Cd stress. Whole transcriptome sequencing (RNA-Seq) analysis was performed with lllumina sequencing technology, and qRT-PCR was conducted to verify the differential genes. The results obtained were as follows: (1) Short-term low concentration of Cd stress (20 mg/kg) had a transient promotion effect on the growth of sisal roots, but Cd showed a significant inhibitory effect on the growth of sisal roots over time. (2) Under different concentrations of Cd stress, the Cd content in sisal root was greater than that in sisal leaf, and Cd accumulated mainly in sisal roots. (3) With the increase of Cd stress concentration, the antioxidant enzyme catalase activity increased, peroxidase activity showed a decreasing trend, and superoxide dismutase showed a trend of increasing and then decreasing. (4) Transcriptome sequencing analysis detected 123 differentially expressed genes (DEGs), among which 85 genes were up-regulated and 38 genes were down-regulated. The DEGs were mainly concentrated in flavonoid biosynthesis and glutathione metabolism, and both processes had some regulatory effects on the Cd tolerance characteristics of sisal. This study elucidated the physiological, biochemical and transcriptomic responses of sisal under cadmium stress, and provided a theoretical basis for the ecological restoration function of sisal.

Antimicrobial Zeolitic Imidazolate Frameworks with Dual Mechanisms of Action.

The horizontal transfer of drug-resistant genes and the formation of biofilm barriers have threatened the therapeutic efficacy of conventional antibiotic drugs. Development of non-antibiotic agents with high delivery efficiency through bacterial biofilms is urgently required. A pyrithione (PT)-loading zeolitic imidazolate framework (ZIF-8@PT) is synthesized to destroy biofilms and improve the sensitivity of bacteria to PT. ZIF-8@PT can target and destroy the biofilm as well as the cell membrane, promoting the intracellular delivery of PT and possibly its interaction with SmpB, a protein that could regulate the drug resistance of bacteria. ZIF-8@PT effectively suppresses abdominal infections induced by multiresistant Aeromonas veronii C4 in rodent models without systemic toxicity. ZIF-8@PT promises wide applications in treating infections caused by multidrug-resistant bacteria through a dual mechanism of action.

AFLP analysis and zebra disease resistance identification of 40 sisal genotypes in China.

Sisal is the most important fiber crop in tropical and subtropical areas in China and the world. Zebra disease is a serious threat to the main cultivar Agave hybrid No.11648 (H.11648) worldwide. To select germplasm materials with zebra disease resistance for breeding, the fluorescent amplified fragment length polymorphism (AFLP) technique was used to make a cluster analysis of the genetic relationships of 40 sisal genotypes grown in China, and Phytophthora nicotianae was used to inoculate the 40 genotypes to identify their resistance to zebra disease. As a result, the similarity coefficient among 40 sisal genotypes was found to be 0.44-0.83 and the 40 genotypes show different levels of disease resistance. According to the AFLP analysis, the disease resistance and chromosomal ploidy, it can be reasoned that, A. attenuata var. marginata, Dong 109, Nan ya 1 and A. attenuata are suitable for hybridization with H.11648 to breed a new disease-resistant variety.

Development of a Specific Nested PCR Assay for the Detection of 16SrI Group Phytoplasmas Associated with Sisal Purple Leafroll Disease in Sisal Plants and Mealybugs.

Sisal purple leafroll disease (SPLD) is currently the most destructive disease affecting sisal in China, yet its aetiology remains unclear. In our previous research, it was verified to be associated with phytoplasmas, and nested PCR based on the 16S rRNA gene using universal primers R16mF2/R16mR1 followed by R16F2n/R16R2 was confirmed as the most effective molecular method for the detection of phytoplasmas associated with SPLD (SPLDaP). However, the method has a shortcoming of inaccuracy, for it could produce false positive results. To further manage the disease, accurate detection is needed. In this study, we developed a specific nested PCR assay using universal primers R16F2n/R16R2, followed by a set of primers designed on 16Sr gene sequences amplified from SPLDaP, nontarget bacteria from sisal plants, and other phytoplasma subgroups or groups. This established method is accurate, specific, and effective for detection of 16SrI group phytoplasma in sisal, and its sensitivity is up to 10 fg/µL of total DNA. It also minimized the false positive problem of nested PCR using universal primers R16mF2/R16mR1 followed by R16F2n/R16R2. This method was further used to verify the presence of phytoplasma in Dysmicoccusneobrevipes, and the results showed that D. neobrevipes could be infected by SPLDaP and thus could be a candidate for vector transmission assays.

Phylogeny and Expression Atlas of the NITRATE TRANSPORTER 1/PEPTIDE TRANSPORTER FAMILY in Agave.

Agave species are widely cultivated crassulacean acid metabolism (CAM) plants for alcoholic beverages, food and fiber production. Among these, the Agave hybrid H11648 ((A. amaniensis × A. angustifolia) × A. amaniensis) is the main cultivar for sisal fiber in the tropical areas of Brazil, China, and African countries. The plants of Agave hybrid H11648 have a long life cycle and large leaves, which require a huge amount of nitrogen nutrient. However, the molecular basis of nitrogen transport and allocation has not been well understood in agave. In this study, we identified 19 NITRATE TRANSPORTER 1/PEPTIDE TRANSPORTER FAMILY(NPF) genes (called AhNPFs) with full-length coding sequences in Agave hybrid H11648. Our analysis of gene expression in various types of tissues revealed the tissue-specific expression pattern of AhNPFs. We further examined their expression patterns at different leaf developmental stages, under abiotic/biotic stresses and nutrient deficiency. The results reveal several candidate regulators in the agave NPF family, including AhNPF4.3/5.2/7.1. We first characterized the NPF genes in agave based on published leaf transcriptome datasets and emphasized their potential functions. The study will benefit future studies related to nitrogen nutrient in agave.

The complete chloroplast genome of Coffea liberica (Gentianales: Rubiaceae).

Coffee is one of the most popular beverages around the world. As one of the best-known coffee species, Liberian coffee (Coffea liberica Bull ex Hiern 1876) has a high resistance to leaf rust, a devasting disease caused by Hemileia vastatrix. However, there are few reports on the systematic position and phylogenetic relationship of C. liberica at the chloroplast (cp) genome level. Thus, we successfully assembled its cp genome. The full length is 154,799 bp with a GC content of 37.48%. We have further annotated the cp genome and predicted 85 protein-coding genes together with 8 rRNAs and 37 tRNAs. Furthermore, a large single copy region (LSC), a small single copy region (SSC), an inverted repeat region a (IRa) and an inverted repeat region b (IRb) are identified with lengths of 84,868 bp, 18,121 bp, 25,905 bp and 25,905 bp, respectively. The phylogenetic tree indicates that C. liberica is closely related to C. canephora, which is consistent with a previous result obtained from genotyping-by-sequencing.

The complete chloroplast genome of Agave amaniensis (Asparagales: Asparagaceae: Agavoideae).

Agave amaniensis Trel. & W. Nowell (1933) has long been used for phytosteroid production, which is also one of the parents of the famous Agave hybrid cultivar 11648 for sisal fiber production. However, its systematic position and phylogenetic relationship remains unknown at the chloroplast (cp) genome level. Therefore, we have sequenced and assembled the cp genome of A. amaniensis via Illumina sequencing. The cp genome is 157,282 bp in length with a GC content of 37.84%. A large single-copy region of 85,899 bp, a small single-copy region of 18,233 bp, and inverted repeat regions of 26,575 bp were found in the cp genome. Based on the annotation, 86 protein-coding genes, eight rRNAs, and 38 tRNAs were identified in the cp genome with total lengths of 78,981 bp, 9050 bp, and 2867 bp, respectively. The phylogenetic tree indicates that A. amaniensis is closely related with A. H11648, A. angustifolia, and A. americana.

Antifungal activity of montmorillonite/peptide aptamer nanocomposite against Colletotrichum gloeosporioides on Stylosanthes.

Chemical agents are effective treatment methods for anthracnose induced by pathogenic Colletotrichum gloeosporioides on Stylosanthes. However, excess consumption of chemical agents destroys the environment, synthetic biology was capable of conquering the issue. The antifungal agent is developed by enclosing a bio-synthesized peptide aptamer with layered montmorillonite via electrostatic interaction. Compared with free peptide aptamer, the nanocomposite exhibits higher antifungal activity against Colletotrichum gloeosporioides, further improving the utilization of peptide aptamer. The nanocomposite killed Colletotrichum gloeosporioides by releasing peptide aptamer after they entered the spore. Moreover, montmorillonite enhances the adhesion ability of peptide aptamer via hydrophobic interactions between nanomaterials and leaves, prolonging the extension time of nanocomposite on leaves. Consequently, 0.1 mg of nanocomposite demonstrates a comparable effect to commercial carbendazim (1 %) to prevent anthracnose on leaves of Stylosanthes induced by HK-04 at room temperature. This work demonstrates an alternative to commercial antifungal agents and proposes a versatile approach to preparing environmental-friendly antifungal agents to inhibit fungal infections on crops.