甘蔗GLY基因家族的鉴定及GLYI-1基因的功能分析OA

The glyoxalase system,comprising glyoxalase I(GLYI)and glyoxalase II(GLYⅡ),serves as a key mecha-nism for detoxifying excess methylglyoxal(MG)in plants and plays an important role in responses to abiotic stress and pathogen infection.To date,genome-wide identification and expression analysis of GLY gene family have not been re-ported in sugarcane.In this study,we identified 50 SsGLYI genes and 52 SsGLYⅡ genes from the wild sugarcane Sac-charum spontaneum,and systematically analyzed the physicochemical properties,gene structures,promoter cis-acting elements,and expression patterns.SsGLY genes were randomly distributed across 30 chromosomes.All 43 SsGLYI members contained a conserved Motif1(PF00903),while all SsGLYII proteins possessed a conserved Motif1(PF00753).A total of 39 SsGLYI proteins contained four metal-binding sites(H/Q,L,H,E),except SsGLYII8.1-8.4 from subfamily IV,which were Zn2+-dependent,the remaining SsGLYI proteins were Ni2+-dependent.Only 26 SsGLYI proteins con-tained both the THxHxDH metal-binding domain and the C/GHT active site.Collinearity analysis identified 41 pairs of collinear genes,among which 39 pairs had Ka/Ks values less than 1,indicating that the SsGLY gene family has under-gone predominant purifying selection during evolution.The expression levels of SsGLYI subfamily V and SsGLYⅡsubfamily Ⅲ were higher than those of the other four subfamilies under infection by Sporisorium scitamineum.Notably,the expression of SsGLYI3.4 showed differences in its expression patterns between the resistant genotype YT93-159 and the susceptible genotype ROC22.Furthermore,we cloned the homologous gene ScGLYI-1 of SsGLYI3.4 from YT93-159,which was constitutively expressed and primarily localized to the chloroplast.Meanwhile,the expression of ScGLYI-1 could be up-regulated by exogenous salicylic acid(SA)and smut pathogen stress,indicating that this gene may play a crucial role in response to pathogen stress in sugarcane.This study would provide a theoretical foundation for further elucidating the function of glyoxalase genes in sugarcane.