Studies On Rice 14-3-3 Gene Family And Screening Of Genes Downstream Of Xa3/Xa26 Disease Resistance Pathway

Rice bacterial blight and rice bacterial steak disease are damage caused by Gram-negative xanthomonas and they all seriously affect the rice yield.It is an effective strategy to reduce the disease to provide sufficient theoretical basis for rice breeding via exploring the mechanism of interactions between rice and pathogens.The 14-3-3 proteins in plants,like the highly conserved homologous proteins in mammals,serves as a major regulator of basal metabolism and cell signaling.14-3-3 in rice is a family of genes with 8 members,and 14-3-3b protein has high sequence similarity to 14-3-3e protein.In this study,14-3-3b and 14-3-3e overexpression transgenic materials,RNA interference(RNAi)transgenic materials and CRISPR/Cas9 system transgenic materials were obtained by genetic transformation.14-3-3b overexpressing plants showed enhanced disease resistance inoculated with Xanthomonas oryzae pv.Oryzae.When 14-3-3b overexpressing plants were inoculated with Xanthomonas oryzae pv.Orycola RS105,they also showed resistant phenotype.Os EDR1(enhanced disease resistance 1)is a kind of Raf-like mitogen-activated protein kinase kinase kinase(MAPKKK)in rice.Osedr1 mutant shows resistance to bacterial blight and has obvious lesion mimic on leaves.Yeast two-hybrid experiment showed that 14-3-3b and 14-3-3e interacted with Os EDR1 in yeast.Subcellular localization results showed that 14-3-3b was distributed in the cytoplasm and nucleus.The relationship between 14-3-3b,Os EDR1 and 14-3-3e proteins,as well as the specific mechanisms involved in the disease resistance of rice need further study.MPKK10.2 acts as a mitogen-activated protein kinase kinase(MAPKK)in rice,and its function is mainly based on mitogen-activated protein kinase signal cascade.In this study,it was confirmed that MPKK10.2 could interact with downstream mitogen-activated protein kinase(MAPK)MPK6 and MPK3 in the nucleus by yeast two-hybrid experiment and rice protoplast dual-fluorescence complementary experiment during disease resistance process in rice,and inhibited MPK6 expression in MPKK10.2overexpressing transgenic material.In addition,in order to explore the function of phosphokinase kinase kinase MPKKa and MPKKe in rice,the mutant was obtained by CRISPR/Cas9 system.The disease resistant mechanism of major disease resistance gene in rice has been a hot topic.Xa3/Xa26 is a major resistance gene to bacterial blight cloned by our laboratory,but little is known about its specific signal transduction pathways.Based on the gene expression profile of Xa3/Xa26 gene,the genomic editing technique based on CRISPR/Cas9 system was used to obtain the transgenic plants of 7 candidate genes.We found that transgenic plants lacking of NDCP gene function were susceptible to rice bacterial blight.How does NDCP and Xa3/Xa26 collaborate in regulating rice disease need to be further explored.