Study On The Regulation Of The Immune-related Gene PRG1 On Pid3-mediated Blast Resistance In Rice

Blast is one of the most destructive diseases of rice,which severely threatens rice food security.The blast resistance gene Pid3 was previously cloned from Digu.Rice plants carrying the transgene Pid3 confer resistance to M.oryzae.However,little is known on the molecular mechanism of Pid3-mediated resistance.In this study,we performed mass spectrum(MS)-mediated phosphorylation comparison analysis on Pid3 plants between compatible infection with the strain ZB15 and incompatible infection with the strain Zhong-10-8-14.We found the protein encoded by PRG1(Pid3-related genes,PRG)presents of which,the phosphorylation level post the incompatible infection is much lower than post the compatible infection.Protein sequence analysis suggests that PRG1 encodes a protein containing a domain that might interact with Avr protein.By using CRISPR/Cas9 technology,we knocked out(KO)PRG1 in rice plants carrying Pid3(Pid3-TP309),and obtained four independent homozygous transgenic lines in knocking out of PRG1,PRG1-KO.Both spraying and punch inoculations show that PRG1-KO plants possess compromised resistance to Zhong-10-8-14 compared with Pid3-TP309.This result indicates that PRG1 is essential for Pid3-mediated resistance.Our study will provide not only insight on understanding Pid3-mediated resistance but also the theoretical basis for blast resistance breeding.