The PHYB-FOF2-VOZ2 module functions to fine-tune flowering in response to changes in light quality by modulating FLC expression in Arabidopsis.

Proper timing for plants to flower under different environmental conditions is critical for their propagation. Light quality is a pivotal environmental cue that plays a critical role in regulating flowering. Plants tend to flower late under light with high red (R)/far-red (FR) light ratio, whereas flower early under light with a low R/FR light ratio. However, how plants fine-tune flowering in response to changes in light quality is not well understood. Here, we demonstrate that the F-box Protein F-box of Flowering 2 (FOF2), an autonomous pathway-related regulator, physically interacts with VASCULAR PLANT ONE-ZINC FINGER 1 and 2 (VOZ1 and VOZ2), which are the direct downstream factors of R/FR light receptor phytochrome B (PHYB). Furthermore, we show that PHYB physically interacts with FOF2 and mediates FR light and end-of-day far-red light (EOD-FR) stabilization of the FOF2 protein and enhances FOF2 binding to VOZ2, leading to VOZ2 protein degradation by SCFFOF2 E3 ligase. In contrast, PHYB mediates R light and end-of-day red light (EOD-R) degradation of FOF2 protein. Genetic interaction studies demonstrate that FOF2 functions downstream of PHYB to promote FLC expression and inhibit flowering under both high R/FR light and simulated shade conditions, which partially depend on VOZ proteins. Taken together, our findings suggest a novel mechanism whereby plants fine-tune flowering time through PHYB-FOF2-VOZ2 module that modulates FLC expression in response to changes in light quality.

Study on the Efficacy and Potential Mechanism of Topical Shen Bai Hair Growing Decoction against Androgenetic Alopecia Based on Ultrahigh Performance Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry and RNA-seq.

Androgenetic alopecia (AGA) is a major problem that can happen to people of all ages, leading to psychological problems, such as anxiety and depression. Topical Shen Bai hair growing decoction (TSBHGD) is based on the pathogenesis of AGA, combined with Traditional Chinese Medicine theory, improved by the Tianjin Academy of Traditional Chinese Medicine Affiliated Hospital according to its clinical treatment experience. This study was designed to demonstrate the therapeutic efficacy of TSBHGD against AGA, analyze the chemical components of TSBHGD as well as the skin-retained and blood-retained components in mice after topical administration of TSBHGD, and clarify the mechanism of its therapeutic efficacy. It was demonstrated that TSBHGD could suppress TNF-α and IL-6 levels and improve pathological phenomena such as hair loss, reduced follicle density, and dermal thickness caused by testosterone solution. Totally 35 components were identified in TSBHGD extracts, 12 skin-retained components were identified in drug-containing skin, and 7 blood-retained components were identified in drug-containing plasma, according to ultrahigh performance liquid chromatography quadrupole time-of-flight mass spectrometry. Transcriptomic sequencing revealed that some of the genes in AGA mice had altered expression patterns, which could be reversed by TSBHGD. Through network pharmacology analysis, it was found that TSBHGD mainly regulated eight signaling pathways, among which the apoptosis signaling pathway ranked first with a significance of 0.00149. Finally, both Bcl-2 and Caspase family proteins in the apoptosis signaling pathway were examined by Western blot. It was confirmed that TSBHGD could inhibit the apoptosis level in AGA mice's skin tissue to exert an anti-AGA effect. This will facilitate the development of new-generation herbal compound formulas with precise efficacy and provide novel ideas for AGA therapy.

DFT Predirected Molecular Engineering Design of Donor-Acceptor Structured g-C3 N4 for Efficient Photocatalytic Tetracycline Abatement.

The photocatalytic environmental decontamination ability of carbon nitride (g-C3 N4 , CN) typically suffers from their inherent structural defects, causing rapid recombination of photogenerated carriers. Conjugating CN with tailored donor-acceptor (D-A) units to counteract this problem through electronic restructuring becomes a feasible strategy, where confirmation by density functional theory (DFT) calculations becomes indispensable. Herein, DFT is employed to predirect the copolymerization modification of CN by benzene derivatives, screening benzaldehyde as the optimal electron-donating candidate for the construction of reoriented intramolecular charge transfer path. Experimental characterization and testing corroborate the formation of a narrowed bandgap as well as high photoinduced carrier separation. Consequently, the optimal BzCN-2 exhibited superior photocatalytic capacity in application for tetracycline hydrochloride degradation, with 3.73 times higher than that of CN. Besides, the BzCN-2-based photocatalytic system is determined to have a toxicity-mitigating effect on TC removal via T.E.S.T and prefers the removal of dissociable TC2- species under partial alkalinity. This work provides insight into DFT guidance for the design of D-A conjugated polymer and its application scenarios in photocatalytic decontamination.

The zinc finger protein DHHC09 S-acylates the kinase STRK1 to regulate H2O2 homeostasis and promote salt tolerance in rice.

Soil salinity results in oxidative stress and heavy losses to crop production. The S-acylated protein SALT TOLERANCE RECEPTOR-LIKE CYTOPLASMIC KINASE 1 (STRK1) phosphorylates and activates CATALASE C (CatC) to improve rice (Oryza sativa L.) salt tolerance, but the molecular mechanism underlying its S-acylation involved in salt signal transduction awaits elucidation. Here, we show that the DHHC-type zinc finger protein DHHC09 S-acylates STRK1 at Cys5, Cys10, and Cys14 and promotes salt and oxidative stress tolerance by enhancing rice H2O2-scavenging capacity. This modification determines STRK1 targeting to the plasma membrane or lipid nanodomains and is required for its function. DHHC09 promotes salt signaling from STRK1 to CatC via transphosphorylation, and its deficiency impairs salt signal transduction. Our findings demonstrate that DHHC09 S-acylates and anchors STRK1 to the plasma membrane to promote salt signaling from STRK1 to CatC, thereby regulating H2O2 homeostasis and improving salt stress tolerance in rice. Moreover, overexpression of DHHC09 in rice mitigates grain yield loss under salt stress. Together, these results shed light on the mechanism underlying the role of S-acylation in RLK/RLCK-mediated salt signal transduction and provide a strategy for breeding highly salt-tolerant rice.

Exploration of quality variation and stability of hybrid rice under multi-environments.

Improving quality is an essential goal of rice breeding and production. However, rice quality is not solely determined by genotype, but is also influenced by the environment. Phenotype plasticity refers to the ability of a given genotype to produce different phenotypes under different environmental conditions, which can be a representation of the stability of traits. Seven quality traits of 141 hybrid combinations, deriving from the test-crossing of 7 thermosensitive genic male sterile (TGMS) and 25 restorer lines, were evaluated at 5 trial sites with intermittent sowing of three to five in Southern China. In the Yangtze River Basin, it was observed that delaying the sowing time of hybrid rice combinations leads to an improvement in their overall quality. Twelve parents were identified to have lower plasticity general combing ability (GCA) values with increased ability to produce hybrids with a more stable quality. The parents with superior quality tend to exhibit lower GCA values for plasticity. The genome-wide association study (GWAS) identified 13 and 15 quantitative trait loci (QTLs) associated with phenotype plasticity and BLUP measurement, respectively. Notably, seven QTLs simultaneously affected both phenotype plasticity and BLUP measurement. Two cloned rice quality genes, ALK and GL7, may be involved in controlling the plasticity of quality traits in hybrid rice. The direction of the genetic effect of the QTL6 (ALK) on alkali spreading value (ASV) plasticity varies in different cropping environments. This study provides novel insights into the dynamic genetic basis of quality traits in response to different cropping regions, cultivation practices, and changing climates. These findings establish a foundation for precise breeding and production of stable and high-quality rice. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01442-3.

Endophytic Enterobacter sp. YG-14 mediated arsenic mobilization through siderophore and its role in enhancing phytostabilization.

Soil arsenic (As) phytoremediation has long faced the challenge of efficiently absorbing As by plant accumulators while maintaining their health and fast growth. Even at low doses, arsenic is highly toxic to plants. Therefore, plant growth-promoting microorganisms that can mediate As accumulation in plants are of great interest. In this study, the endophyte Enterobacter sp. YG-14 (YG-14) was found to have soil mobilization activity. By constructing a siderophore synthesis gene deletion mutant (ΔentD) of YG-14, the endophyte was confirmed to effectively mobilize Fe-As complexes in mining soil by secreting enterobactin, releasing bioavailable Fe and As to the rhizosphere. YG-14 also enhances As accumulation in host plants via extracellular polymer adsorption and specific phosphatase transfer protein (PitA) absorption. The root accumulation of As was positively correlated with YG-14 root colonization. In addition, YG-14 promoted plant growth and alleviated oxidative damage in R. pseudoacacia L. under arsenic stress. This is the first study, from phenotype, physiology, and molecular perspectives, to determine the role of endophyte in promoting As phytostabilization and maintaining the growth of the host plant. This demonstrated the feasibility of using endophytes with high siderophore production to assist host plants in As phytoremediation.

Protective effects of liriodendrin on myocardial infarction-induced fibrosis in rats via the PI3K/Akt autophagy pathway: A network pharmacology study.

BACKGROUND: Liriodendrin (LIR) has been reported to improve cardiac function in rats following myocardial infarction. However, its role and mechanism in reparative myocardial fibrosis remain unclear. METHODS: In this study, a rat model of myocardial fibrosis was established via left anterior descending artery ligation and randomly divided into three groups (n = 6 per group): sham-operated, myocardial infarction, and LIR intervention (100 mg/kg/day) groups. The pharmacological effects of LIR were assessed using echocardiography, hematoxylin, and eosin (H&E) staining, and Masson staining. Network pharmacology and bioinformatics were utilized to identify potential mechanisms of LIR, which were further validated via western blot analysis. RESULTS: Our findings demonstrated that LIR improved cardiac function, histology scores, and collagen volume fraction. Moreover, LIR downregulated the expression of Beclin-1, LC3-II, and LC3-I while upregulating the expression of p62, indicating LIR-activated autophagy in the heart after myocardial infarction. Further analysis revealed that the PI3K/Akt signaling pathway was significantly enriched and validated by western blot. This analysis suggested that the ratios of p-PI3K/PI3K, p Akt/Akt, and p-mTOR/mTOR were significantly increased. CONCLUSION: LIR may attenuate myocardial infarction-induced fibrosis in rats by inhibiting excessive myocardial autophagy, with the potential mechanism involving the activation of the PI3K/Akt/mTOR pathway.

The protein phosphatase PC1 dephosphorylates and deactivates CatC to negatively regulate H2O2 homeostasis and salt tolerance in rice.

Catalase (CAT) is often phosphorylated and activated by protein kinases to maintain hydrogen peroxide (H2O2) homeostasis and protect cells against stresses, but whether and how CAT is switched off by protein phosphatases remains inconclusive. Here, we identified a manganese (Mn2+)-dependent protein phosphatase, which we named PHOSPHATASE OF CATALASE 1 (PC1), from rice (Oryza sativa L.) that negatively regulates salt and oxidative stress tolerance. PC1 specifically dephosphorylates CatC at Ser-9 to inhibit its tetramerization and thus activity in the peroxisome. PC1 overexpressing lines exhibited hypersensitivity to salt and oxidative stresses with a lower phospho-serine level of CATs. Phosphatase activity and seminal root growth assays indicated that PC1 promotes growth and plays a vital role during the transition from salt stress to normal growth conditions. Our findings demonstrate that PC1 acts as a molecular switch to dephosphorylate and deactivate CatC and negatively regulate H2O2 homeostasis and salt tolerance in rice. Moreover, knockout of PC1 not only improved H2O2-scavenging capacity and salt tolerance but also limited rice grain yield loss under salt stress conditions. Together, these results shed light on the mechanisms that switch off CAT and provide a strategy for breeding highly salt-tolerant rice.

The Rice Endophyte-Derived α-Mannosidase ShAM1 Degrades Host Cell Walls To Activate DAMP-Triggered Immunity against Disease.

Endophytes play an important role in shaping plant growth and immunity. However, the mechanisms for endophyte-induced disease resistance in host plants remain unclear. Here, we screened and isolated the immunity inducer ShAM1 from the endophyte Streptomyces hygroscopicus OsiSh-2, which strongly antagonizes the pathogen Magnaporthe oryzae. Recombinant ShAM1 can trigger rice immune responses and induce hypersensitive responses in various plant species. After infection with M. oryzae, blast resistance was dramatically improved in ShAM1-inoculated rice. In addition, the enhanced disease resistance by ShAM1 was found to occur through a priming strategy and was mainly regulated through the jasmonic acid-ethylene (JA/ET)-dependent signaling pathway. ShAM1 was identified as a novel α-mannosidase, and its induction of immunity is dependent on its enzyme activity. When we incubated ShAM1 with isolated rice cell walls, the release of oligosaccharides was observed. Notably, extracts from the ShAM1-digested cell wall can enhance the disease resistance of the host rice. These results indicated that ShAM1 triggered immune defense against pathogens by damage-associated molecular pattern (DAMP)-related mechanisms. Our work provides a representative example of endophyte-mediated modulation of disease resistance in host plants. The effects of ShAM1 indicate the promise of using active components from endophytes as plant defense elicitors for the management of plant disease. IMPORTANCE The specific biological niche inside host plants allows endophytes to regulate plant disease resistance effectively. However, there have been few reports on the role of active metabolites from endophytes in inducing host disease resistance. In this study, we demonstrated that an identified α-mannosidase protein, ShAM1, secreted by the endophyte S. hygroscopicus OsiSh-2 could activate typical plant immunity responses and induce a timely and cost-efficient priming defense against the pathogen M. oryzae in rice. Importantly, we revealed that ShAM1 enhanced plant disease resistance through its hydrolytic enzyme (HE) activity to digest the rice cell wall and release damage-associated molecular patterns. Taken together, these findings provide an example of the interaction mode of endophyte-plant symbionts and suggest that HEs derived from endophytes can be used as environmentally friendly and safe prevention agent for plant disease control.

Transcriptome-wide profiling of RNA N4-cytidine acetylation in Arabidopsis thaliana and Oryza sativa.

Acetylation of N4-cytidine (ac4C) has recently been discovered as a novel modification of mRNA. RNA ac4C modification has been shown to be a key regulator of RNA stability, RNA translation, and the thermal stress response. However, its existence in eukaryotic mRNAs is still controversial. In plants, the existence, distribution pattern, and potential function of RNA ac4C modification are largely unknown. Here we report the presence of ac4C in the mRNAs of both Arabidopsis thaliana and rice (Oryza sativa). By comparing two ac4C sequencing methods, we found that RNA immunoprecipitation and sequencing (acRIP-seq), but not ac4C sequencing, was suitable for plant RNA ac4C sequencing. We present transcriptome-wide atlases of RNA ac4C modification in A. thaliana and rice mRNAs obtained by acRIP-seq. Analysis of the distribution of RNA ac4C modifications showed that ac4C is enriched near translation start sites in rice mRNAs and near translation start sites and translation end sites in Arabidopsis mRNAs. The RNA ac4C modification level is positively correlated with RNA half-life and the number of splicing variants. Similar to that in mammals, the translation efficiency of ac4C target genes is significantly higher than that of other genes. Our in vitro translation results confirmed that RNA ac4C modification enhances translation efficiency. We also found that RNA ac4C modification is negatively correlated with RNA structure. These results suggest that ac4C is a conserved mRNA modification in plants that contributes to RNA stability, splicing, translation, and secondary structure formation.

Receptor-Like Cytoplasmic Kinase STK Confers Salt Tolerance in Rice.

BACKGROUND: Soil salinization is a major abiotic environmental stress factor threatening crop production throughout the world. Salt stress drastically affects the growth, development, and grain yield of rice (Oryza sativa L.), and the improvement of rice tolerance to salt stress is a desirable approach for meeting increasing food demand. Receptor-like cytoplasmic kinases (RLCKs) play essential roles in plant growth, development and responses to environmental stresses. However, little is known about their functions in salt stress. Previous reports have demonstrated that overexpression of an RLCK gene SALT TOLERANCE KINASE (STK) enhances salt tolerance in rice, and that STK may regulate the expression of GST (Glutathione S-transferase) genes. RESULTS: The expression of STK was rapidly induced by ABA. STK was highest expressed in the stem at the heading stage. STK was localized at the plasma membrane. Overexpression of STK in rice increased tolerance to salt stress and oxidative stress by increasing ROS scavenging ability and ABA sensitivity. In contrast, CRISPR/Cas9-mediated knockout of STK increased the sensitivity of rice to salt stress and oxidative stress. Transcriptome sequencing analysis suggested that STK increased the expression of GST genes (LOC_Os03g17480, LOC_Os10g38140 and LOC_Os10g38710) under salt stress. Reverse transcription quantitative PCR (RT-qPCR) suggested that four stress-related genes may be regulated by STK including OsABAR1, Os3BGlu6, OSBZ8 and OsSIK1. CONCLUSIONS: These findings suggest that STK plays a positive regulatory role in salt stress tolerance by inducing antioxidant defense and associated with the ABA signaling pathway in rice.

Dephosphorylation of CatC at Ser-18 improves salt and oxidative tolerance via promoting its tetramerization in rice.

Catalase (CAT) is a vital antioxidant enzyme, while phosphorylation pivotally regulates its function. Many phosphosites have been identified in CAT, but their functions remained largely elusive. We functionally studied five phosphoserines (Ser-9, -10, -11, -18, and -205) of CatC in rice (Oryza sativa L.). Phospho-Ser-9 and - 11 and dephospho-Ser-18 promoted the enzymatic activity of CatC and enhanced oxidative and salt tolerance in yeast. Phosphorylation status of Ser-18 did not affect CatC peroxisomal targeting and stability, but dephospho-Ser-18 promoted CatC tetramerization to enhance its activity. Moreover, overexpression of dephospho-mimic form CatCS18A in rice significantly improved the tolerance to salt and oxidative stresses by inhibiting the H2O2 accumulation. Together, these results elucidate the mechanism underlying dephosphorylation at Ser-18 promotes CatC activity and salt tolerance in rice. Ser-18 is a promising candidate phosphosite of CatC for breeding highly salt-tolerant rice.

The blue light receptor CRY1 interacts with FIP37 to promote N6 -methyladenosine RNA modification and photomorphogenesis in Arabidopsis.

Light is a particularly important environmental cue that regulates a variety of diverse plant developmental processes, such as photomorphogenesis. Blue light promotes photomorphogenesis mainly through the activation of the photoreceptor cryptochrome 1 (CRY1). However, the mechanism underlying the CRY1-mediated regulation of growth is not fully understood. Here, we found that blue light induced N6 -methyladenosine (m6 A) RNA modification during photomorphogenesis partially via CRY1. Cryptochrome 1 mediates blue light-induced expression of FKBP12-interacting protein 37 (FIP37), which is a component of m6 A writer. Moreover, we showed that CRY1 physically interacted with FIP37 in vitro and in vivo, and mediated blue light activation of FIP37 binding to RNA. Furthermore, CRY1 and FIP37 modulated m6 A on photomorphogenesis-related genes PIF3, PIF4, and PIF5, thereby accelerating the decay of their transcripts. Genetically, FIP37 repressed hypocotyl elongation under blue light, and fip37 mutation could partially rescue the short-hypocotyl phenotype of CRY1-overexpressing plants. Together, our results provide a new insight into CRY1 signal in modulating m6 A methylation and stability of PIFs, and establish an essential molecular link between m6 A modification and determination of photomorphogenesis in plants.

Isobavachalcone Activates Antitumor Immunity on Orthotopic Pancreatic Cancer Model: A Screening and Validation.

Pancreatic cancer is accompanied by poor prognosis and accounts for a significant number of deaths every year. Since Psoralea corylifolia L. (PCL) possesses a broad spectrum of bioactivities, it is commonly used in traditional Chinese medicine. The study explored potential antitumor agents of PCL and underlying mechanisms in vitro and vivo. Based on network pharmacology, bioinformatics, and molecular docking, we considered isobavachalcone (IBC) as a valuable compound. The activity and potential mechanisms of IBC were investigated by RT-qPCR, immunohistochemistry, immunofluorescence, and flow cytometry. It was confirmed that IBC could inhibit Panc 02 cell proliferation and induce apoptosis via increasing the production of reactive oxygen species. IBC could attenuate the weight of solid tumors, increase CD8+ T cells, and reduce M2 macrophages in the tumor tissue and spleen. Another promising finding was that IBC alleviated the proportion of myeloid-derived suppressor cells (MDSCs) in the tumor tissue but had no change in the spleen. The study of pharmacological effects of IBC was carried out and suggested IBC restrained M2-like polarization of RAW 264.7 cells by inhibiting the expression of ARG1 and MRC1 and suppressed the expression of ARG1 and TGF-ß in bone marrow-derived MDSC. In summary, this research screened IBC as an antineoplastic agent, which could attenuate the growth of pancreatic cancer via activating the immune activity and inducing cell apoptosis. It might be a reference for the antitumor ability of IBC and the treatment of the tumor microenvironment in pancreatic cancer.

The Vital Role of ShTHIC from the Endophyte OsiSh-2 in Thiamine Biosynthesis and Blast Resistance in the OsiSh-2-Rice Symbiont.

Endophytes can benefit the growth and stress resistance of host plants by secreting bioactive components. Thiamine is an essential vitamin involved in many metabolic pathways and can only be synthesized by microbes and plants. In this study, we found that thiamine could inhibit the development of the phytopathogen Magnaporthe oryzae and decrease the rice blast index under field conditions. In the thiamine biosynthesis pathway, the key enzyme ShTHIC of an endophyte Streptomyces hygroscopicus OsiSh-2 and OsTHIC of rice (Oryza sativa) were highly homologous. Gene overexpression or knockout approaches revealed that both THIC contributed to thiamine synthesis and resistance to M. oryzae. Furthermore, S. hygroscopicus OsiSh-2 colonization led to a decrease in the thiamine synthesis level of rice but still maintained thiamine homeostasis in rice. However, inoculation with the ShTHIC knockout strain ΔTHIC reduced the thiamine content in rice, although the thiamine synthesis level of rice was increased. After infection with M. oryzae, blast resistance was dramatically improved in OsiSh-2-inoculated rice but decreased in ΔTHIC-inoculated rice compared with non-inoculated rice. This result demonstrated that ShTHIC could regulate thiamine biosynthesis and consequently assist blast resistance in the OsiSh-2-rice symbiont. Our results revealed a novel blast-resistance mechanism mediated by a key thiamine biosynthetic enzyme from an endophyte OsiSh-2.

Screening DHHCs of S-acylated proteins using an OsDHHC cDNA library and bimolecular fluorescence complementation in rice.

S-acylation is an important lipid modification that primarily involves DHHC proteins (DHHCs) and associated S-acylated proteins. No DHHC-S-acylated protein pair has been reported so far in rice (Oryza sativa L.) and the molecular mechanisms underlying S-acylation in plants are largely unknown. We constructed an OsDHHC cDNA library for screening corresponding pairs of DHHCs and S-acylated proteins using bimolecular fluorescence complementation assays. Five DHHC-S-acylated protein pairs (OsDHHC30-OsCBL2, OsDHHC30-OsCBL3, OsDHHC18-OsNOA1, OsDHHC13-OsNAC9, and OsDHHC14-GSD1) were identified in rice. Among the pairs, OsCBL2 and OsCBL3 were S-acylated by OsDHHC30 in yeast and rice. The localization of OsCBL2 and OsCBL3 in the endomembrane depended on S-acylation mediated by OsDHHC30. Meanwhile, all four OsDHHCs screened complemented the thermosensitive phenotype of an akr1 yeast mutant, and their DHHC motifs were required for S-acyltransferase activity. Overexpression of OsDHHC30 in rice plants improved their salt and oxidative tolerance. Together, these results contribute to our understanding of the molecular mechanism underlying S-acylation in plants.

OsSRK1, a lectin receptor-like kinase, controls plant height by mediating internode elongation in Oryza sativa L.

LecRLKs (lectin receptor-like kinases) is a subfamily of RLKs (receptor like kinase) and takes part in mounds of biological processes in plant-environment interaction. However, the roles of LecRLKs in plant development are still elusive. Here, we showed that OsSRK1, belonging to LecRLK family in rice, had a relative higher expression in internode and stem in comparison with that in root and leaf. Importantly, srk1-1 and srk1-2, two genome-edited mutants of OsSRK1 using CRISPR/Cas9 system, exhibited obviously a decreased plant height and shorter length of the first internode and second internode compared with those in WT. Subsequently, histochemical sectioning showed that the stem diameter and the cell length in stem are significantly reduced in srk1-1 and srk1-2 compared with WT. Moreover, analyzing the expression of four gibberellin biosynthesis related genes showed that CPS, KAO, KS1, and GA3ox2 expression had similar levels between WT and mutants. Importantly, we further verified that OsSRK1 can directly interact with gibberellin receptor GID1. Together, our results revealed that LecRLKs family member OsSRK1 positively regulated plant height by controlling internode elongation which maybe depended on OsSRK1-GID1 interaction mediated gibberellin signaling transduction. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-022-01340-6.

Endophytic Streptomyces hygroscopicus OsiSh-2-Mediated Balancing between Growth and Disease Resistance in Host Rice.

Plants fine-tune the growth-defense trade-off to survive when facing pathogens. Meanwhile, plant-associated microbes, such as the endophytes inside plant tissues, can benefit plant growth and stress resilience. However, the mechanisms for the beneficial microbes to increase stress resistance with little yield penalty in host plants remain poorly understood. In the present study, we report that endophytic Streptomyces hygroscopicus OsiSh-2 can form a sophisticated interaction with host rice, maintaining cellular homeostasis under pathogen-infection stress, and optimize plant growth and disease resistance in rice. Four-year field trials consistently showed that OsiSh-2 could boost host resistance to rice blast pathogen Magnaporthe oryzae while still maintaining a high yield. The integration of the proteomic, physiological, and transcriptional profiling analysis revealed that OsiSh-2 induced rice defense priming and controlled the expression of energy-consuming defense-related proteins, thus increasing the defense capability with the minimized costs of plant immunity. Meanwhile, OsiSh-2 improved the chloroplast development and optimally maintained the expression of proteins related to plant growth under pathogen stress, thus promoting the crop yield. Our results provided a representative example of an endophyte-mediated modulation of disease resistance and fitness in the host plant. The multilayer effects of OsiSh-2 implicate a promising future of using endophytic actinobacteria for disease control and crop yield promotion. IMPORTANCE Under disease stress, activation of defense response in plants often comes with the cost of a reduction in growth and yield, which is referred as the growth-defense trade-off. The microorganisms which can be recruited by plants to mitigate the growth-defense trade-off are of great value in crop breeding. Here, we reported a rice endophytic actinomycetes Streptomyces hygroscopicus OsiSh-2, which can improve host performances on resistance to rice blast while still sustaining high yield in the 4-year field trials. The proteomic, physiological, and transcriptional profiling data offer insights into the molecular basis underlying the balancing between defense and growth in OsiSh-2-rice symbiont. The findings provide an example for the endophyte-mediated modulation of growth-defense trade-offs in plants and indicated the promising application of endophytic actinobacterial strains in agriculture to breed "microbe-optimized crops."

AtMYB32 regulates the ABA response by targeting ABI3, ABI4 and ABI5 and the drought response by targeting CBF4 in Arabidopsis.

The Arabidopsis thaliana R2R3-MYB transcription factor AtMYB32 and its homologs AtMYB4 and AtMYB7 play crucial roles in the regulation of phenylpropanoid metabolism. In addition, AtMYB4 and AtMYB7 are involved in the response to abiotic stress. However, the function of AtMYB32 remains unclear. In this study, we found that AtMYB32 is induced by abscisic acid (ABA) and repressed by drought stress. AtMYB32 positively regulates ABA-mediated seed germination and early seedling development. The expression of ABSCISIC ACID-INSENSITIVE 3 (ABI3), ABI4 and ABI5, which encode key positive regulators of ABA signaling, was upregulated in response to ABA in AtMYB32-overexpressing plants and downregulated in the atmyb32-1 mutant. In addition, we found that the atmyb32-1 mutant was drought resistant. Consistent with the drought-resistant phenotype, the transcript levels of C-repeat binding factor 4 (CBF4) were higher in the atmyb32-1 mutant in response to drought stress. Electrophoretic mobility shift assays (EMSAs) and chromatin immunoprecipitation (ChIP) assays revealed that AtMYB32 binds directly to the ABI3, ABI4, ABI5 and CBF4 promoters both in vitro and in vivo. Genetically, ABI4 was found to be epistatic to AtMYB32 for ABA-induced inhibition of seed germination and early seedling development. Taken together, our findings revealed that AtMYB32 regulates the ABA response by directly promoting ABI3, ABI4 and ABI5 expression and that the drought stress response likely occurs because of repression of CBF4 expression.

Attenuation of Aeromonas hydrophila Infection in Carassius auratus by YtnP, a N-acyl Homoserine Lactonase from Bacillus licheniformis T-1.

In this experiment, the quorum quenching gene ytnP of Bacillus licheniformis T-1 was cloned and expressed, and the effect against infection of Aeromonas hydrophila ATCC 7966 was evaluated in vitro and vivo. The BLAST results revealed a 99% sequence identity between the ytnP gene of T-1 and its homolog in B.subtilis sub sp. BSP1, and the dendroGram showed that the similarity in the YtnP protein in T-1 was 100% in comparison with B.subtilis 3610, which was categorized as the Aidc cluster of the MBL family. The AHL lactonase activity of the purified YtnP was detected as 1.097 ± 0.7 U/mL with C6-HSL as the substrate. Otherwise, purified YtnP protein could significantly inhibit the biofilm formation of A.hydrophila ATCC 7966 with an inhibition rate of 68%. The MIC of thiamphenicol and doxycycline hydrochloride against A. hydrophila reduced from 4 µg/mL and 0.5 µg/mL to 1 µg/mL and 0.125 µg/mL, respectively, in the presence of YtnP. In addition, YtnP significantly inhibited the expression of five virulence factors hem, ahyB, ast, ep, aerA of A. hydrophila ATCC 7966 as well (p < 0.05). The results of inhibition on virulence showed a time-dependence tendency, while the strongest anti-virulence effects were within 4-24 h. In vivo, when the YtnP protein was co-injected intraperitoneally with A. hydrophila ATCC 7966, it attenuated the pathogenicity of A. hydrophila and the accumulated mortality was 27 ± 4.14% at 96 h, which was significantly lower than the average mortality of 78 ± 2.57% of the Carassius auratus injected with 108 CFU/mL of A. hydrophila ATCC 7966 only (p < 0.001). In conclusion, the AHL lactonase in B. licheniformis T-1 was proven to be YtnP protein and could be developed into an agent against infection of A. hydrophila in aquaculture.