内源多胺对山葡萄性别分化的影响OA

[Objective]Vitis amurensis is the most cold-resistant species in the genus,bearing mostly hermaphroditic flowers,and is widely distributed in Northeast China.This study aimed to investigate the effects of polyamines on sex differentiation in V.amurensis,thereby providing critical insights for enhan-cing the utilization of its germplasm resources and improving grape flower development.[Method]The hermaphroditic flowers Shuangfeng,Shuanghong,Shuangyou and male plants 043,75030,75134 of V.amu-rensis were used as experimental materials.The content of endogenous polyamines,including spermine(Spm),spermidine(Spd),and putrescine(Put),in flower buds during the critical sex differentiation phase was quantified by high performance liquid chromatography(HPLC),and their ratios were analyzed.The male plants 75134 were transformed into hermaphroditic flowers through cytokinin(CPPU)treatment.The changes in polyamine content during sex conversion process and the relationship between their ratios and sex formation were analyzed.Additionally,transcriptome analysis was conducted on male plants 75134 by CPPU treatment and the control group to identify critical metabolic pathways and key genes associated with sex conversion in V.amurensis.[Result]During the critical period of sex differentiation,compared with male plants,the flower buds of hermaphroditic plants of V.amurensis exhibited higher Spm and Spd contents,as well as larger Spd/Put,Spm/Put,and(Spd+Spm)/Put ratios.After CPPU treatment,male plants were transformed into hermaphroditic plants,accompanied by a decrease in Put content and an in-crease in Spd and Spm contents in the flower buds.Hierarchical clustering results of differentially expressed genes divided them into 73 clusters.Cluster 34 contained genes encoding ATPases involved in polyamine transport,showing significant enrichment.The KEGG results indicated that the spermine meta-bolic pathway and the β-alanine metabolic pathway were involved in the sex conversion in V.amurensis.Furthermore,combined analysis of metabolic pathway and gene annotations identified node[1.5.3.16]as a differentially expressed gene commonly annotated in both arginine metabolic pathway and β-alanine meta-bolic pathway,corres-ponding to the gene annotation of spermine deoxyase gene 5[V.vinifera].[Conclu-sion]Polyamines are involved in the sex differentiation of V.amurensis.The spermine metabolic pathway and the β-alanine metabolic pathway are critical for sex conversion in V.amurensis,with the spermine deoxyase gene 5 identified as a key regulatory gene.