CRISPR/Cas9 Directed Mutagenesis To Study Salicylic Acid And Brassinosteroides Signaling Pathway Genes In Rice

Salicylic acid（SA）and Brassinosteroids（BRs）are two major plant hormones involved in many plant developmental processes and plant defence mechanisms.However,the current knowledge of the signaling pathway of SA and BRs in plant defence regulation and control of agronomic traits are limited in Rice as compared to Arabidopsis.This study focused on the development of mutants of SA signaling genes involved in disease resistance as well as BRs signaling genes involved in rice plant architecture.CRISPR（Clustered regularly interspaced short palindromic repeats）and CRISPR-associated proteins system has emerged as the most effective genome editing tool for gene knockout due to its simplicity,high efficiency,and versatility.We reported that the CRISPR/Cas9 system was employed to knockout the SA and BR signaling genes in Rice.The rice NPR1 gene plays an essential role in the salicylic acid signaling pathway and mediates disease resistance in multiple genes.However,information about the function of NPR1 in plant-pathogen interaction is limited.First,conducted the bioinformatics analysis to study gene characterization,domain analysis,phylogenetic relationship.In addition,we found that selection of callus and sg RNA is conducive to improving the gene targeting efficiency of CRISPR-Cas9.Moreover,analysis of the genotypes,phenotypes,and edited Os NPR1,Os NPR2,Os NPR3,Os NPR4/5,and Os NPR6 in T₀,T₁,and T₂,will be utilized transgenic rice plants in crop breeding.Brassinosteroids is an important steroid plant hormone that plays key role in plant development.In this study,we develop knockout mutants of BR signaling genes Os D11,Os BZR1 and Os GSK1.The mutants analysis with BR sensitive phenotype contained plant height and leaf angle.The interaction between Os BZR1 and Os GSK1 was studied by yeast two-hybrid assay.Overall,these results aid in further SA signaling pathway basis underlying NPR1 mediation of Rice’s disease resistance and development process.Besides,the BR mutants might offer a practical tool to study new interactions to find out more novel components in BR signaling pathway in the near future.