Year-end Sale % OFF 
Abstract
Lipids and lipid metabolites play important roles in plant-microbe interactions. Despite the extensive studies of lipases in lipid homeostasis and seed oil biosynthesis, the involvement of lipases in plant immunity remains largely unknown. In particular, GDSL esterases/lipases, characterized by the conserved GDSL motif, are a subfamily of lipolytic enzymes with broad substrate specificity. Here, we functionally identified two GDSL lipases, OsGLIP1 and OsGLIP2, in rice immune responses. Expression of OsGLIP1 and OsGLIP2 was suppressed by pathogen infection and salicylic acid (SA) treatment. OsGLIP1 was mainly expressed in leaf and leaf sheath, while OsGLIP2 showed high expression in elongating internodes. Biochemical assay demonstrated that OsGLIP1 and OsGLIP2 are functional lipases that could hydrolyze lipid substrates. Simultaneous down-regulation of OsGLIP1 and OsGLIP2 increased plant resistance to both bacterial and fungal pathogens, whereas disease resistance in OsGLIP1 and OsGLIP2 overexpression plants was significantly compromised, suggesting that both genes act as negative regulators of disease resistance. OsGLIP1 and OsGLIP2 proteins mainly localize to lipid droplets and the endoplasmic reticulum (ER) membrane. The proper cellular localization of OsGLIP proteins is indispensable for their functions in immunity. Comprehensive lipid profiling analysis indicated that the alteration of OsGLIP gene expression was associated with substantial changes of the levels of lipid species including monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG). We show that MGDG and DGDG feeding could attenuate disease resistance. Taken together, our study indicates that OsGLIP1 and OsGLIP2 negatively regulate rice defense by modulating lipid metabolism, thus providing new insights into the function of lipids in plant immunity.
Highlights
Plants are continuously challenged by invading microorganisms, some of which are pathogens that threaten plant survival and cause a big loss of production in crops
Biochemical, and lipid profiling assays, our work indicated that OsGLIP1 and OsGLIP2 are functional lipases involved in lipid metabolism and negatively modulate rice immune responses
We identified a GDSL lipase gene, Os06g0129600 (OsGLIP1), the expression of which was suppressed after Xanthomonas oryzae pv. oryzae (Xoo) inoculation
Summary
Plants are continuously challenged by invading microorganisms, some of which are pathogens that threaten plant survival and cause a big loss of production in crops. A polymer matrix composed of short-chain fatty acids (FA), and wax, a mixture of verylong-chain fatty acids, form a physical barrier preventing pathogen infection [5]. Lipids and their derivatives have been implicated as signaling molecules that could modulate plant immunity [6]. The identification of DIR1 (DEFECTIVE IN INDUCED RESISTANCE 1) as a potential lipid transfer protein provided strong evidence that a lipid-derived molecule was involved in long distance defense signaling [12]. G3P and AzA cooperate with DIR1 and another predicted lipid transfer protein AZELAIC ACID INDUCED 1 (AZI1) to form a feedback regulatory loop that regulates systemic immunity in plants [15]. Further investigation of DIR1 and AZI1 lipid transfer activities and their target lipid molecules would provide invaluable insights into the roles of lipids in plant immunity
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
