Search

Introduction: Sessile plants engage in trade-offs between growth and defense capacity in response to fluctuating environmental cues. MYB is an important transcription factor that plays many important roles in controlling plant growth and defense. However, the mechanism behind how it keeps a balance between these two physiological processes is still largely unknown. Objectives: Our work focuses on the dissection of the molecular mechanism by which GhMYB33 regulates plant growth and defense. Methods: The CRISPR/Cas9 technique was used to generate mutants for deciphering GhMYB33 functions. Yeast two-hybrid, luciferase complementary imaging, and co-immunoprecipitation assays were used to prove that proteins interact with each other. We used the electrophoretic mobility shift assay, yeast one-hybrid, and luciferase activity assays to analyze GhMYB33 acting as a promoter. A β-glucuronidase fusion reporter and 5′ RNA ligase mediated amplification of cDNA ends analysis showed that ghr-miR319c directedly cleaved the GhMYB33 mRNA. Results: Overexpressing miR319c-resistant GhMYB33 (rGhMYB33) promoted plant growth, accompanied by a significant decline in resistance against Verticillium dahliae. Conversely, its knockout mutant, ghmyb33, demonstrated growth restriction and concomitant augmentation of V. dahliae resistance. GhMYB33 was found to couple with the DELLA protein GhGAI1 and bind to the specific cis-elements of GhSPL9 and GhDFR1 promoters, thereby modulating internode elongation and plant resistance in V. dahliae infection. The ghr-miR319c was discovered to target and suppress GhMYB33 expression. The overexpression of ghr-miR319c led to enhanced plant resistance and a simultaneous reduction in plant height. Conclusion: Our findings demonstrate that GhMYB33 encodes a hub protein and controls the expression of GhSPL9 and GhDFR1, implicating a pivotal role for the miR319c-MYB33 module to regulate the trade-offs between plant growth and defense.

Water stress (drought and waterlogging) is one highly important factor affecting food security in China. Investigating the effects of soil moisture stress on the morphological and physiological characteristics of maize seedlings is crucial for ensuring food production. The use of spectral monitoring to observe crop phenotypic traits and assess crop health has become a focal point in field crop research. However, studies exploring the contribution of crop phenotypic and physiological data to the Normalized Difference Vegetation Index (NDVI) are still limited. In this study, a 35-day pot experiment was conducted with seven soil moisture gradients: 50%, 60%, 70%, 80% (control group, CK), 90%, 100%, and 110% treatment. In order to investigate the effects of soil moisture stress on seedling phenotypes, antioxidant enzyme activities, and NDVI, an ASD FieldSpec 4 Hi-Res NG portable spectrometer was used to collect spectral data from maize (Zea mays L. B73) leaves. The contributions of maize phenotypic and physiological traits to NDVI were also examined. The results indicated that (1) the 50% and 110% treatments significantly affected maize seedling phenotypes compared to the CK group; (2) the activities of superoxide dismutase (SOD) and peroxidase (POD) in the leaves increased under water stress, while the activities of glutathione peroxidase (GSH-PX) and ascorbate peroxidase (APX) decreased; (3) soil moisture stress (drought and waterlogging) reduced photosynthetic pigments, chlorophyll content (SPAD), and NDVI, with inhibitory effects intensifying as the stress level increased; (4) Redundancy analysis showed that antioxidant enzymes explained 69.87% of the variation in seedling height, leaf area, and NDVI. Soil moisture stress, chlorophyll, and SPAD explained 58.14% of the variation in these parameters. The results demonstrated that maize seedlings were highly sensitive to soil moisture changes, and the SPAD value contributed significantly to NDVI (p < 0.01). This study provides valuable insights for future research in precision agriculture management [ABSTRACT FROM AUTHOR]

SUMMARY: Verticillium dahliae, a soil‐borne fungal pathogen, compromises host innate immunity by secreting a plethora of effectors, thereby facilitating host colonization and causing substantial yield and quality losses. The mechanisms underlying the modulation of cotton immunity by V. dahliae effectors are predominantly unexplored. In this study, we identified that the V. dahliae effector Vd6317 inhibits plant cell death triggered by Vd424Y and enhances PVX viral infection in Nicotiana benthamiana. Attenuation of Vd6317 significantly decreased the virulence of V. dahliae, whereas ectopic expression of Vd6317 in Arabidopsis and cotton enhanced susceptibility to V. dahliae infection, underscoring Vd6317's critical role in pathogenicity. We observed that Vd6317 targeted the Arabidopsis immune regulator AtNAC53, thereby impeding its transcriptional activity on the defense‐associated gene AtUGT74E2. Arabidopsis nac53 and ugt74e2 mutants exhibited heightened sensitivity to V. dahliae compared to wild‐type plants. A mutation at the conserved residue 193L of Vd6317 abrogated its interaction with AtNAC53 and reduced the virulence of V. dahliae, which was partially attributable to a reduction in Vd6317 protein stability. Our findings unveil a hitherto unrecognized regulatory mechanism by which the V. dahliae effector Vd6317 directly inhibits the plant transcription factor AtNAC53 activity to suppress the expression of AtUGT74E2 and plant defense. Significance Statement: Verticillium dahliae effector Vd6317 regulates plant immunity. [ABSTRACT FROM AUTHOR]

Summary: Heavy metal pollution poses a significant risk to human health and wreaks havoc on agricultural productivity. Phytoremediation, a plant‐based, environmentally benign, and cost‐effective method, is employed to remove heavy metals from contaminated soil, particularly in agricultural or heavy metal‐sensitive lands. However, the phytoremediation capacity of various plant species and germplasm resources display significant genetic diversity, and the mechanisms underlying these differences remain hitherto obscure. Given its potential benefits, genetic improvement of plants is essential for enhancing their uptake of heavy metals, tolerance to harmful levels, as well as overall growth and development in contaminated soil. In this study, we uncover a molecular cascade that regulates cadmium (Cd2+) tolerance in cotton, involving GhRCD1, GhbHLH12, GhMYB44, and GhHMA1. We identified a Cd2+‐sensitive cotton T‐DNA insertion mutant with disrupted GhRCD1 expression. Genetic knockout of GhRCD1 by CRISPR/Cas9 technology resulted in reduced Cd2+ tolerance in cotton seedlings, while GhRCD1 overexpression enhanced Cd2+ tolerance. Through molecular interaction studies, we demonstrated that, in response to Cd2+ presence, GhRCD1 directly interacts with GhbHLH12. This interaction activates GhMYB44, which subsequently activates a heavy metal transporter, GhHMA1, by directly binding to a G‐box cis‐element in its promoter. These findings provide critical insights into a novel GhRCD1–GhbHLH12–GhMYB44–GhHMA1 regulatory module responsible for Cd2+ tolerance in cotton. Furthermore, our study paves the way for the development of elite Cd2+‐tolerant cultivars by elucidating the molecular mechanisms governing the genetic control of Cd2+ tolerance in cotton. [ABSTRACT FROM AUTHOR]

This article, published in the Plant Biotechnology Journal, discusses the use of host-induced gene silencing (HIGS) to target a gene in the cotton plant that confers resistance to Verticillium wilt, a devastating disease caused by the fungus Verticillium dahliae. The researchers investigated the expression pattern and function of a gene called VdEXG, which encodes an exoglucanase enzyme. They found that silencing VdEXG in the cotton plant led to increased resistance to V. dahliae infection. Additionally, they identified an interacting protein called GhRD21A that plays a role in enhancing cotton resistance to the fungus. These findings provide a new strategy for breeding wilt-resistant cotton cultivars. [Extracted from the article]

MYB transcription factors play important roles during abiotic stress responses in plants. However, little is known about the accurate systematic analysis of MYB genes in the four cotton species, Gossypium hirsutum, G. barbadense, G. arboreum and G. raimondii. Herein, we performed phylogenetic analysis and showed that cotton MYBs and Arabidopsis MYBs were clustered in the same subfamilies for each species. The identified cotton MYB s were distributed unevenly on chromosomes in various densities for each species, wherein genome-wide tandem and segment duplications were the main driving force of MYB family expansion. Synteny analysis suggested that the abundant collinearity pairs of MYB s were identified between G. hirsutum and the other three species, and that they might have undergone strong purification selection. Characteristics of conserved motifs, along with their consensus sequence, promoter cis elements and gene structure, revealed that MYB proteins might be highly conserved in the same subgroups for each species. Subsequent analysis of differentially expressed genes and expression patterns indicated that most GhMYB s might be involved in response to drought (especially) and salt stress, which was supported by the expression levels of nine GhMYB s using real-time quantitative PCR. Finally, we performed a workflow that combined virus-induced gene silencing and the heterologous transformation of Arabidopsis , which confirmed the positive roles of GhMYB s under drought conditions, as validated by determining the drought-tolerant phenotypes, damage index and/or water loss rate. Collectively, our findings not only expand our understanding of the relationships between evolution and function of MYB genes, but they also provide candidate genes for cotton breeding. [ABSTRACT FROM AUTHOR]

Osteoporotic bone defects, a severe complication of osteoporosis, are distinguished by a delayed bone healing process and poor repair quality. While bone marrow‐derived mesenchymal stem cells (BMMSCs) are the primary origin of bone‐forming osteoblasts, their mitochondrial function is impaired, leading to inadequate bone regeneration in osteoporotic patients. Melatonin is well‐known for its antioxidant properties and regulation on bone metabolism. The present study postulated that melatonin has the potential to enhance the repair of osteoporotic bone defects by restoring the mitochondrial function of BMMSCs. In vitro administration of melatonin at varying concentrations (0.01, 1, and 100 μM) demonstrated a significant dose‐dependent improvement in the mitochondrial function of BMMSCs obtained from ovariectomized rats (OVX‐BMMSCs), as indicated by an elevation in mitochondrial membrane potential, adenosine triphosphate synthesis and expression of mitochondrial respiratory chain factors. Melatonin reduced the level of mitochondrial superoxide by activating the silent information regulator type 1 (SIRT1) and its downstream antioxidant enzymes, particularly superoxide dismutase 2 (SOD2). The protective effects of melatonin were found to be nullified upon silencing of Sirt1 or Sod2, underscoring the crucial role of the SIRT1‐SOD2 axis in the melatonin‐induced enhancement of mitochondrial energy metabolism in OVX‐BMMSCs. To achieve a sustained and localized release of melatonin, silk fibroin scaffolds loaded with melatonin (SF@MT) were fabricated. The study involved the surgical creation of bilateral femur defects in OVX rats, followed by the implantation of SF@MT scaffolds. The results indicated that the application of melatonin partially restored the mitochondrial energy metabolism and osteogenic differentiation of OVX‐BMMSCs by reinstating mitochondrial redox homeostasis. These findings suggest that the localized administration of melatonin through bone implants holds potential as a therapeutic approach for addressing osteoporotic bone defects. [ABSTRACT FROM AUTHOR]

Summary: Plant somatic embryogenesis (SE) is a multifactorial developmental process where embryos that can develop into whole plants are produced from somatic cells rather than through the fusion of gametes. The molecular regulation of plant SE, which involves the fate transition of somatic cells into embryogenic cells, is intriguing yet remains elusive.We deciphered the molecular mechanisms by which GhRCD1 interacts with GhMYC3 to regulate cell fate transitions during SE in cotton. While silencing of GhMYC3 had no discernible effect on SE, its overexpression accelerated callus formation, and proliferation.We identified two of GhMYC3 downstream SE regulators, GhMYB44 and GhLBD18. GhMYB44 overexpression was unconducive to callus growth but bolstered EC differentiation. However, GhLBD18 can be triggered by GhMYC3 but inhibited by GhMYB44, which positively regulates callus growth. On top of the regulatory cascade, GhRCD1 antagonistically interacts with GhMYC3 to inhibit the transcriptional function of GhMYC3 on GhMYB44 and GhLBD18, whereby a CRISPR‐mediated rcd1 mutation expedites cell fate transition, resembling the effects of GhMYC3 overexpression. Furthermore, we showed that reactive oxygen species (ROS) are involved in SE regulation.Our findings elucidated that SE homeostasis is maintained by the tetrapartite module, GhRCD1–GhMYC3–GhMYB44–GhLBD18, which acts to modulate intracellular ROS in a temporal manner. [ABSTRACT FROM AUTHOR]

Cotton (Gossypium spp.) is one of the most important fiber crops worldwide. In the last two decades, transgenesis and genome editing have played important roles in cotton improvement. However, genotype dependence is one of the key bottlenecks in generating transgenic and gene‐edited cotton plants through either particle bombardment or Agrobacterium‐mediated transformation. Here, we developed a shoot apical meristem (SAM) cell‐mediated transformation system (SAMT) that allowed the transformation of recalcitrant cotton genotypes including widely grown upland cotton (Gossypium hirsutum), Sea island cotton (Gossypium barbadense), and Asiatic cotton (Gossypium arboreum). Through SAMT, we successfully introduced two foreign genes, GFP and RUBY, into SAM cells of some recalcitrant cotton genotypes. Within 2–3 months, transgenic adventitious shoots generated from the axillary meristem zone could be recovered and grown into whole cotton plants. The GFP fluorescent signal and betalain accumulation could be observed in various tissues in GFP‐ and RUBY‐positive plants, as well as in their progenies, indicating that the transgenes were stably integrated into the genome and transmitted to the next generation. Furthermore, using SAMT, we successfully generated edited cotton plants with inheritable targeted mutagenesis in the GhPGF and GhRCD1 genes through CRISPR/Cas9‐mediated genome editing. In summary, the established SAMT transformation system here in this study bypasses the embryogenesis process during tissue culture in a conventional transformation procedure and significantly accelerates the generation of transgenic and gene‐edited plants for genetic improvement of recalcitrant cotton varieties. [ABSTRACT FROM AUTHOR]

Subtilases (SBTs), which belong to the serine peptidases, control plant development by regulating cell wall properties and the activity of extracellular signaling molecules, and affect all stages of the life cycle, such as seed development and germination, and responses to biotic and abiotic environments. In this study, 146 Gossypium hirsutum, 138 Gossypium barbadense, 89 Gossypium arboreum and 84 Gossypium raimondii SBTs were identified and divided into six subfamilies. Cotton SBTs are unevenly distributed on chromosomes. Synteny analysis showed that the members of SBT1 and SBT4 were expanded in cotton compared to Arabidopsis thaliana. Co-expression network analysis showed that six Gossypium arboreum SBT gene family members were in a network, among which five SBT1 genes and their Gossypium hirsutum and Arabidopsis thaliana direct homologues were down-regulated by salt treatment, indicating that the co-expression network might share conserved functions. Through co-expression network and annotation analysis, these SBTs may be involved in the biological processes of auxin transport, ABA signal transduction, cell wall repair and root tissue development. In summary, this study provides valuable information for the study of SBT genes in cotton and excavates SBT genes in response to salt stress, which provides ideas for cotton breeding for salinity resistance. [ABSTRACT FROM AUTHOR]

Summary: Cotton's fundamental requirements for long periods of growth and specific seasonal temperatures limit the global arable areas that can be utilized to cultivate cotton. This constraint can be alleviated by breeding for early‐maturing varieties. By delaying the sowing dates without impacting the boll‐opening time, early‐maturing varieties not only mitigate the yield losses brought on by unfavorable weathers in early spring and late autumn but also help reducing the competition between cotton and other crops for arable land, thereby optimizing the cropping system. This review presents studies and breeding efforts for early‐maturing cotton, which efficiently pyramid early maturity, high‐quality, multiresistance traits, and suitable plant architecture by leveraging pleiotropic genes. Attempts are also made to summarize our current understanding of the molecular mechanisms underlying early maturation, which involves many pathways such as epigenetic, circadian clock, and hormone signaling pathways. Moreover, new avenues and effective measures are proposed for fine‐scale breeding of early‐maturing crops to ensure the healthy development of the agricultural industry. [ABSTRACT FROM AUTHOR]

Treating articular cartilage defects in patients remains a challenging task due to the absence of blood vessels within the cartilage tissue. The regenerative potential is further compromised by an imbalance between anabolism and catabolism, induced by elevated levels of reactive oxygen species. However, the advent of tissue engineering introduces a promising strategy for cartilage regeneration, offering viable solutions such as mechanical support and controlled release of chondrogenic molecules or cytokines. In this study, we developed an antioxidant scaffold by incorporating natural silk fibroin (SF) and kartogenin (KGN)-loaded liposomes (SF-Lipo@KGN). The scaffold demonstrated appropriate pore size, connectivity, and water absorption and the sustained release of KGN was achieved through the encapsulation of liposomes. In vitro experiments revealed that the SF-Lipo@KGN scaffolds exhibited excellent biocompatibility, as evidenced by enhanced cell adhesion, migration, and proliferation of chondrocytes. The SF-Lipo@KGN scaffolds were found to stimulate cartilage matrix synthesis through the activation of the nuclear factor erythroid-2-related factor 2/heme oxygenase-1 antioxidant signaling pathway. In vivo experiments demonstrated the effective promotion of articular cartilage regeneration by the SF-Lipo@KGN scaffolds, which enhanced extracellular matrix anabolism and restored the intrinsic redox homeostasis. Overall, this study successfully developed biomimetic KGN-loaded scaffolds that restore cartilage redox homeostasis, indicating promising prospects for cartilage tissue engineering. [ABSTRACT FROM AUTHOR]

Cotton is one of the Uyghur medical materials in China and is rich in flavonoids. Flavonoids have important pharmacological effects. The yield of flavonoids in traditional extraction methods is low, which affects the development of flavonoids. Therefore, it is urgent to optimize the extraction techniques. The yield of flavonoids in cotton flowers was effectively improved by response surface methodology, and the highest yield of flavonoids reached 5.66%, and the optimal extraction process conditions were obtained. The DPPH free radical scavenging rate, hydroxyl free radical scavenging rate, superoxide anion free radical scavenging rate, and reducing ability were tested to reflect the antioxidant capacity of flavonoids. The flavonoids had an excellent antioxidant effect. Cell experiments suggested that the flavonoids had the effect of protecting glutamate-induced damage to HT-22 cells. The results of this study provide a theoretical basis for the extraction of cotton flowers flavonoids and the comprehensive evaluation of antioxidant products, as well as the extraction of other plant flavonoids. [ABSTRACT FROM AUTHOR]

Keywords: Cotton; Pink fibre; Betalain; Synthetic biology EN Cotton Pink fibre Betalain Synthetic biology 674 676 3 03/28/23 20230401 NES 230401 The vast majority of the world's cotton varieties produce white fibre, which is then coloured with synthetic dyes during textile processing to fulfil the diverse needs of consumers. However, it remains unknown if the betalain pathway can be engineered into cotton plants to alter the colour of cotton fibre without compromising fibre quality. As illustrated in Figures 1m,n,p,t, the fibre length and strength of the transgenic fibres at 45 DPA and mature stage were comparable to those of the WT fibre. [Extracted from the article]

Plant auxin is essential in plant growth and development. However, the molecular mechanisms of auxin involvement in plant immunity are unclear. Here, we addressed the function of the cotton (Gossypium hirsutum) miR393-TIR1 module in plant defense against Verticillium dahliae infection via auxin perception and signaling. GhTIR1 was directedly cleaved by ghr-miR393 according to mRNA degradome data, 5′-RACE analysis, and a GUS reporter assay. Ghr-miR393 knockdown significantly increased plant susceptibility to V. dahliae compared to the control, while ghr-miR393 overexpression and GhTIR1 knockdown significantly increased plant resistance. External indole-3-acetic acid (IAA) application significantly enhanced susceptibility to V. dahliae in ghr-miR393 knockdown and control plants compared to mock treatment, and only slightly increased susceptibility in overexpressing ghr-miR393 and GhTIR1-silenced plants. Application of external PEO-IAA (an auxin antagonist) had a contrary trend with IAA application. Based on yeast two-hybrid and bimolecular fluorescence complementation assays, GhTIR1 interacted with GhIAA14 in the nucleus, and GhIAA14 knockdown reduced plant resistance to V. dahliae infection. The results suggested that the ghr-miR393-GhTIR1 module regulates plant defense via auxin perception and signaling. Additionally, simultaneous knockdown of GhTIR1 and GhICS1 significantly increased plant susceptibility to V. dahliae compared to the control, indicating that salicylic acid (SA) accumulation is vital for the ghr-miR393-GhTIR1 module to regulates plant resistance. Transcriptome data also demonstrated that GhTIR1 knockdown significantly downregulated expression of auxin-related genes and upregulated expression of SA-related genes. Overall, the ghr-miR393-GhTIR1 module participates in plant response to V. dahliae infection via IAA perception and signaling partially depending on the SA defense pathway. [ABSTRACT FROM AUTHOR]

During somatic embryogenesis (SE), somatic cells initiate embryogenic development under appropriate conditions. Uniconazole, a plant growth regulator, was found to inhibit the proliferation of callus but promoted the conversion of callus into an embryogenic callus (EC) in cotton. The supplementation of uniconazole in the culture medium significantly suppressed the endogenous auxin [indole acetic acid (IAA)] level in callus tissues in both the callus initiation and proliferation stage but enhanced the abscisic acid (ABA) level only in the callus proliferation stage. Exogenous ABA and uniconazole showed cooperative effects on promoting the differentiation rate of callus into EC. These findings were verified by RNA-seq analysis, which elucidated that the genes involved in the IAA biosynthesis, metabolism, and signaling, and ABA metabolism pathways were regulated by uniconazole during the callus development and SE. Overall, the results suggest that uniconazole could modulate callus proliferation and callus differentiation rate by regulating the endogenous levels of IAA and ABA. [ABSTRACT FROM AUTHOR]

Detached organs or differentiated tissues could form a mass of pluripotent cells termed as callus on an auxin-rich medium, the underlying molecular mechanism of which remains elusive in cotton. LATERAL ORGAN BOUNDARIES DOMAIN (LBD) transcription factor is a key regulator of plant cell totipotency/pluripotency, and a number of cotton GhLBDs with high-level differential expression during the callus induction process have been identified. Their overexpression in cotton calli fostered promotions in and callus induction without exogenous auxin. Expression analysis and histological observation using paraffin sectioning suggested that the first 72 h on culture is a key time point for callus initiation, whereby the GhLBDs showed high transcript abundance and enlarged calli that were rapidly developed from procambium and cambium. GhLBDs' expression level could be precisely modulated by the gradient concentrations of exogenous auxin, whereas auxin transport inhibitor 2,3,5-triiodobenzoic acid could severely inhibit its expression. The LBD-mediated callus formation was also dependent on the expression levels of GhLBDs. Further, a β-estradiol-inducible promoter pER8 was used to drive GhLBD18-1 expression, which led to rapid callus proliferation, suggesting that pER8 / GhLBD18-1 could be used as a selectable marker system to replace the existing antibiotic/herbicide-resistance selectable markers in plant transformation. Our study provides new insights for callus initiation regulatory mechanism and strategies for improving transformation efficiency in cotton. [ABSTRACT FROM AUTHOR]

Patatin-like proteins (PLPs) have non-specific lipid acyl hydrolysis (LAH) activity, which can hydrolyze membrane lipids into fatty acids and lysophospholipids. The vital role of PLPs in plant growth and abiotic stress has been well documented. However, the function of PLPs in plant defense responses against pathogens is still poorly understood. Here, we isolated and identified a novel cotton (Gossypium hirsutum) PLP gene GhPLP2. The expression of GhPLP2 was induced upon treatment with Verticillium dahliae , the signaling molecules jasmonic acid (JA) and ethylene (ETH) in cotton plants. Subcellular localization revealed that GhPLP2 was localized to the plasma membrane. GhPLP2 -silenced cotton plants were more susceptible to infection by V. dahliae , while the overexpression of GhPLP2 in Arabidopsis enhanced its resistance to V. dahliae , which was apparent as mild symptoms, and a decrease in the disease index and fungal biomass. The hypersensitive response, deposition of callose, and H2O2 accumulation triggered by V. dahliae elicitor were reduced in GhPLP2 -silenced cotton plants. The overexpression of GhPLP2 in Arabidopsis resulted in the accumulation of linoleic acid (LA, 18:2) and α-linolenic acid (ALA, 18:3) and facilitated the biosynthesis of JA and JA-mediated defensive responses. GhPLP2 silencing in cotton plants consistently reduced the accumulation of linoleic acid (LA, 18:2) and α-linolenic acid (ALA, 18:3) and suppressed the biosynthesis of JA and the defensive responses mediated by JA. These results indicate that GhPLP2 is involved in the resistance of cotton to V. dahliae by maintaining fatty acid metabolism pools for JA biosynthesis and activating the JA signaling pathway. [ABSTRACT FROM AUTHOR]

Verticillium wilt is caused by the soil‐borne vascular pathogen Verticillium dahliae, and affects a wide range of economically important crops, including upland cotton (Gossypium hirsutum). Previous studies showed that expression levels of BIN2 were significantly down‐regulated during infestation with V. dahliae. However, the underlying molecular mechanism of BIN2 in plant regulation against V. dahliae remains enigmatic. Here, we characterized a protein kinase GhBIN2 from Gossypium hirsutum, and identified GhBIN2 as a negative regulator of resistance to V. dahliae. The Verticillium wilt resistance of Arabidopsis and cotton were significantly enhanced when BIN2 was knocked down. Constitutive expression of BIN2 attenuated plant resistance to V. dahliae. We found that BIN2 regulated plant endogenous JA content and influenced the expression of JA‐responsive marker genes. Further analysis revealed that BIN2 interacted with and phosphorylated JAZ family proteins, key repressors of the JA signalling pathway in both Arabidopsis and cotton. Spectrometric analysis and site‐directed mutagenesis showed that BIN2 phosphorylated AtJAZ1 at T196, resulting in the degradation of JAZ proteins. Collectively, these results show that BIN2 interacts with JAZ proteins and plays a negative role in plant resistance to V. dahliae. Thus, BIN2 may be a potential target gene for genetic engineering against Verticillium wilt in crops. [ABSTRACT FROM AUTHOR]

Fungal pathogens secrete effector proteins that regulate host immunity and can suppress basal defence mechanisms against colonization in plants. Verticillium dahliae is a widespread and destructive soilborne fungus that can cause vascular wilt disease and reduces plant yields. However, little is currently known about how the effectors secreted by V. dahliae function. In this study, we analysed and identified 34 candidate effectors in the V. dahliae secretome and found that Vd424Y, a glycoside hydrolase family 11 protein, was highly upregulated during the early stages of V. dahliae infection in cotton plants. This protein was located in the nucleus and its deletion compromised the virulence of the fungus. The transient expression of Vd424Y in Nicotiana benthamiana induced BAK1‐ and SOBIR1‐dependent cell death and activated both salicylic acid and jasmonic acid signalling. This enhanced its resistance to the oomycetes Phytophthora capsici in a way that depended on its nuclear localization signal and signal peptides. Our results demonstrate that Vd424Y is an important effector protein targeting the host nucleus to regulate and activate effector‐triggered immunity in plants. [ABSTRACT FROM AUTHOR]