A previously unrecognized AAA+ ATPase–F-box module that controls receptor homeostasis is revealed and StGCN4 is identified as a promising molecular target for breeding high-yielding and late blight resistant potato cultivars.
Abstract
Fine-tuning immune receptor stability is essential for maintaining the balance between defense and growth in crops. Here, we identify an AAA+ ATPase–F-box regulatory module that negatively regulates potato immunity by promoting the degradation of the immune co-receptor StSOBIR1. The AAA+ ATPase StGCN4 functions as a negative regulator of potato immunity. Silencing of StGCN4 markedly enhanced resistance to Phytophthora infestans without affecting plant growth, while overexpression increased susceptibility. StGCN4 interacts with the PP2-type F-box protein StPFB1 and stabilizes it at the plasma membrane, which also negatively regulate immunity and together they facilitate proteasomal degradation of StSOBIR1, thereby dampening receptor-mediated defense signaling. Suppression of StGCN4 or StPFB1 enhances reactive oxygen species (ROS) production, salicylic acid accumulation, and expression of defense-related genes, resulting in strong resistance to P. infestans without growth penalty. These findings reveal a previously unrecognized AAA+ ATPase–F-box module that controls receptor homeostasis and identify StGCN4 as a promising molecular target for breeding high-yielding and late blight resistant potato cultivars.
An RLCK-V subfamily member in potato is reported, StSOAK1, which negatively regulates disease resistance to the oomycete Phytophthora infestans and the fungus Botrytis cinerea and reveals a regulatory mechanism of potato StRBOHB, which occurs in parallel with its paradigmatic AtPBL13-mediated regulation in Arabidopsis.
Ying-Ying Song, Yong-Ming Chen, J. Qin et al.· Plant Physiology· 0 citations
It is demonstrated that the TaLYK5-TaDSK2a module functions as a molecular switch that dynamically regulates the trade-off between plant immunity and growth.
Yu Wu, Dan Yang, Haibin Zhao et al.· Proceedings of the National...· 0 citations
Potato late blight caused by Phytophthora infestans threatens global food security. Unlike the fact that most race-specific resistance to P. infestans (Rpi) genes is rapidly overcome by evolving pathogen populations, the R8 gene from Solanum demissum has conferred durable, quantitative resistance for nearly a century despite encoding a canonical coiled-coil–type nucleotide-binding, leucine-rich repeat (NLR) protein. We identified specific R8 gene analogs that act as negative modulators of R8-mediated immunity. These R8 gene analogs lack independent resistance functions but perturb the recognition of avirulence effector Avr8 by R8 and interfere with oligomerization and plasma membrane association of NRC2, a helper NLR essential for the R8 signaling pathway. Stable overexpression of such RGAs effectively compromises R8-mediated resistance in both potato and Nicotiana benthamiana. We propose that this endogenous regulation balances the intensity of R8-mediated immunity, likely reducing selection pressure on the pathogen population and prolonging resistance durability. Our findings reveal a regulatory layer where genetically linked RGAs control resistance (R) protein–mediated immunity, providing a conceptual framework for durable resistance breeding.
Jia-Hui Nie, Lang Liu, Ye-Tong Qi et al.· Science Advances· 0 citations
It is found that the amino-terminal domain of TOE3 (T3N) inhibits abscisic acid (ABA) signaling, which reveals how TOE3 uncoupling to provide strategies for breeding crops with strong growth and antiviral immunity.
Bolei Jiao, Baijun Wu, H. Fang et al.· Science Advances· 0 citations
Simple Summary Potato early blight caused by Alternaria solani poses a serious threat to potato yield and quality. Catalase regulates plant immunity against necrotrophic pathogens, yet its function in early blight remains unclear. In this study, A. solani infection induces hydrogen peroxide accumulation in plants, and exogenous H2O2 application markedly accelerates early blight infection. Furthermore, we identified StCAT1 as a positive regulator of resistance to early blight in potato, with its expression significantly upregulated following A. solani induction. Silencing StCAT1 impaired antioxidant capacity and disease resistance, while overexpression exerted the opposite effect. Additionally, StABI5 was identified as an upstream transcription factor that activates StCAT1 expression, and silencing StABI5 compromised potato resistance to early blight. These results indicate that StABI5 can activate the expression of StCAT1 and by mediating the reactive oxygen species (ROS) signaling pathway regulates potato resistance to early blight, which provides a theoretical basis and genetic resources for the molecular breeding of potato resistance to early blight.
Abstract Plant responses to pathogens often rely on receptor-like cytoplasmic kinases (RLCKs) that mediate signaling through interactions with receptor kinases and downstream components. Here, we studied the tomato RLCK, TPK1b Related Protein Kinase (TPK09), and demonstrate its function in integrating defense with light stress responses. Tomato tpk09 mutants exhibited increased susceptibility to Botrytis cinerea and the vascular pathogen Fusarium oxysporum, whereas transgenic expression of TPK09 enhanced resistance to Botrytis. Disease severity in tpk09 mutants was elevated under light-emitting diode (LED) compared to fluorescent light (FL). In the absence of infection, mutants displayed severe necrosis and elevated H2O2 accumulation under LED lighting. TPK09 interacts with the cell death–inducing transglycosylase BcCrh1 from Botrytis. Consistently, TPK09 suppresses cell death triggered by Botrytis infection as well as by BcCrh1 expression. Loss of TPK09 abolished pathogen-induced expression of the tomato suppressor of cell death BAX INHIBITOR-LIKE1 and compromised chitin- and flg22-triggered reactive oxygen species (ROS) accumulation and immune gene activation. Further, TPK09 mitigates damage to the photosynthetic system under elevated light stress, demonstrated by a decrease in the effective photochemical quantum yield of PSII and electron transport rate in the mutant plants. In addition, TPK09 expression is induced by light but suppressed under dark conditions, and the mutant seedlings were insensitive to hypocotyl growth responses to light. RNA sequencing (RNA-seq) studies suggest TPK09 is required for expression of genes involved in light harvesting, photosynthesis, and stress response functions. Collectively, TPK09 plays a key role in enhancing fungal resistance, maintaining the homeostasis of the photosynthetic apparatus and ROS levels, and mitigating photooxidative damage.
Sara Hailemariam, Chao-Jan Liao, Athanas Guzha et al.· Plant Physiology· 0 citations
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