杜梨LRR-XI-a亚家族的鉴定及调控腐烂病抗性的成员筛选OA北大核心CSTPCD

To investigate the mechanism of LRR-XI-a gene family in the immune system of Duli,LRR-XI-a family members of Duli were identified based on Pyrus betulaefolia genome data in GDR database,and members responding to Valsa canker signals were screened by evolutionary characteristics,gene duplication events,and expression pattern analysis.The functions of some members were preliminarily analyzed by combining the transient expression of fruits and resistance gene expression analysis.The results showed that a total of 91 LRR-XI-a genes were identified in the Duli genome,and LRR-XI-a genes were classified into 6 groups based on the phylogenetic evolutionary tree.Gene duplication analysis suggests that the rapid increase in Group Ⅰ membership in Duli may result from both tandem duplication(TD)and whole genome duplication(WGD),while the increase in Group Ⅵ members is caused by WGD alone.Promoter cis-acting element analysis revealed that the LRR-XI-a Group Ⅱ and Ⅵ may be mainly involved in the response to abiotic adversity signals,while the remaining 4 groups simultaneously participate in the response to both biotic and abiotic stress signals.Expression analysis demonstrated that LRR-XI-4 and LRR-XI-5 was up-regulated after Valsa pyri infection,especially LRR-XI-5 was up-regulated more than 586-fold compared with the control.Furthermore,fruit transient expression analysis showed that the overexpression of LRR-XI-4 and LRR-XI-5 reduced the resistance to V.pyri,the expression levels of JA-related genes were lower than the control upon V.pyri infection,whereas the expression of HR-related genes were significantly induced.Overall,gene duplications lead to a rapid increase in LRR-XI-a family members in Duli,which respond to different biotic and abiotic stresses.LRR-XI-4 and LRR-XI-5 play negative roles in regulating the defense against V.pyri in pears by activating HR-related genes expression,which could be considered as candidate genes for further research on Valsa canker resistance.This research provides a foundational framework for further investigation into the underlying mechanisms of pear resistance to diseases and molecular breeding.