Studies on Post transcriptional Reprogramming of Resistance Genes Upon Pathogen Infection in Arabidopsis thaliana

Abstract

16 newlineABSTRACT newlinePlants are constantly exposed to pathogens, which lead to decrease in the newlineproductivity that would threaten food security. Sophisticated mechanisms have been newlineevolved in plants to recognize and respond to such invading pathogens. Primary newlinesensitization of plants to microbes is mediated largely by defense related genes and newlineresistance (R) genes, whose protein counterparts associate with avirulence (Avr) newlineproteins secreted by the pathogens. Regulation of R genes has not been clearly newlineunderstood. R genes and defense related genes are supposedly post-transcriptionally newlineregulated by a eukaryotic surveillance mechanism known as nonsense-mediated newlinemRNA decay (NMD). NMD is a quality control process that causes the shutting off newlineof aberrant messenger RNAs (mRNAs) expression, thus enabling the cell to escape newlinefrom any deleterious effect that might have resulted from the expression of faulty newlinemRNAs. Excitingly, many defense related genes, which are involved in plant newlineimmunity, harbour NMD features that make their protein counterparts unavailable newlineduring normal growth conditions of a cell, suggesting the significance of NMD in newlineplant immunity. NMD-defective mutants in Arabidopsis, shows concurrent newlinephenotypes as those of pathogen resistant mutants. Also, the core NMD factors, newlineUPF1 and UPF3 are known to be involved in plant defense. Still, details of NMDmediated newlineplant defense mechanism are less explored. Extensive studies would be newlineneeded to understand the role of NMD in plant immunity. newlineOur current study points out that NMD acts as a control tower, which newlineprimarily balances plant growth and immunity. We hypothesised that the NMD newlinefactors might be affected during pathogen infection. NMD suppresses the expression newlineof R genes and favours plant growth. Conversely, it has long been inscrutable how newlinethe NMD machinery is impaired during bacterial infection. Here, we demonstrate that newlinethe PRRs perceive the nonself molecules and initiate the degradation of NMD newlinemachineries. It was also found that the decay of NMD core factors was delayed in newlinemp