Plant Cell. The regulatory mechanism of plant-based immunity- unambiguously mediated mRNA decay.

Plant immunity is a mechanism of resistance to pathogen infection. It is composed of extracellular immune receptors (PRR) that recognize MAMP (micro associated molecular patterns) and intracellular immune receptors (including R protein, NLR or NBS-LRR) that recognize pathogen derived effectors [1].among them, R protein is essential for plant basic immunity and effector triggered immunity (ETI). Therefore, it is very important to post-translational modification of R protein and transcriptional regulation of R gene.studies have shown that some complete splicing (FS) and selective splicing (as) of R gene transcription are targets of miRNA and nonsense mediated mRNA decay (NMD) [2].NMD is a conserved messenger RNA (mRNA) quality monitoring system widely existing in the cytoplasm of eukaryotes, which can prevent the translation of mRNA containing premature termination codon (PTC), and is related to the regulation of plant immunity [3].ineffective mutations of Upf1 (up-frameshift 1) or UPF3 increase plant disease resistance by increasing the level of salicylic acid (SA) and the expression of defense genes, and the autoimmunity of NMD damaged mutants is caused by the activation of TNL (TIR-NBS-LRR) type r-dependent immunity, but bacterial infection may inhibit the NMD mechanism in Arabidopsis thaliana [2,4].however, the pathway and mechanism of NMD efficiency decline are still unclear.recently, sang Hyon Kim of Myongji University in South Korea published an online article entitled "pattern associated molecular pattern triggered immunity involved proteolytic degradation of core nonsense mediated mRNA decay factors during the early defense The research paper of response revealed the mechanism of NMD regulating plant basic immunity after bacterial infection.this study found that after PST DC3000 infection, double mutations of Upf1 and UPF3 triggered plant autoimmunity and promoted the rapid accumulation of SA.this study analyzed the structure of R genes in Arabidopsis mutants with NMD damage, and found that most of the transcripts produced by R genes were NMD targets, and the accumulation of these R transcripts led to the enhancement of basic immunity of UPF mutants.in this study, it was found that the recognition of bacterial infection by PRR resulted in the accumulation of a set of TNL and cc-nbs-lrr (CNL) transcripts, indicating that the expression of a subset of R gene was controlled by NMD.this study also showed that Upf1 and UPF3 were destroyed by ubiquitination and 26S proteasome pathway in the early stage of infection, which indicated that the early response of ubiquitination of Upf1 and UPF3 was the key to regulating plant immunity. Therefore, the Upf1 UPF3 double mutants exhibit intensive autoimmunity. Therefore, plants inhibit NMD through UPF degradation, resulting in the stabilization of TNL transcription level in the early stage of bacterial infection, thus improving the basic immunity of plants.NMD is one of the main post transcriptional control pathways involved in maintaining the transcription level of R gene in Arabidopsis thaliana during immune response. [1] Jones, J.D., Vance, R.E., and Dangl, J.L. (2016), 2016) intra cellular immune immune surveillance devices devices devices devices and animals, science 354: aaf6395. [2] glognitzizer, J., akimcheva, S., Srinivasan, A., kusenda, B., riehs, N., stamfl, H, H., bautor, J., dekrout, B., jonak, C., Jimenez Gomez, J., j.science 354: aaff6395. [2] glognitzizer, J., akimcheva, S., Srinivasan, A., kusenda, B., riehs, N, N., stamfl, h, h, h, bautor, J., J., dekrout, B., B., jonak, C., Jimenez Gomez Gomez, J,. M, et al. (2014). Nonsense-mediated mRNA decay modulates immune receptor levels to regulate plant antibacterial defense. Cell Host Microbe 16: 376-390.【3】Peccarelli, M., and Kebaara, B.W. (2014). Regulation of natural mRNAs by the nonsense-mediated mRNA decay pathway. Euk. Cell 13: 1126-1135.【4】Rayson, S., Arciga-Reyes, L., Wootton, L.,De Torres zabala, M., Truman, W., Graham, N., grant, M., and Davies, B. (2012). Pathway responses are induced in Arabidopsis thaliana NMD mutants. PLoS One 7: e31917