强光条件下西施山药叶片褐化比较转录组分析OA

This study aimed to explore the molecular mechanism of leaf browning under high light condi-tions in Dioscorea opposita'Xi Shi'.The physiological indexes of'Xi Shi'leaves under high light conditions were analyzed,and the genes associated with leaf browning were identified through transcriptome analysis.The results showed that compared with the health leaves under shading conditions,the browning leaves under high light conditions had higher activities of catalase,peroxidase and superoxide dismutase,higher contents of pro-line,malondialdehyde and anthocyanin,and lower chlorophyll content.Further transcriptome analysis of leaf samples was conducted by high-throughput sequencing,and a total of 190 557 transcripts were obtained after the assembly by Trinity software,with the length ranging from 500 bp to 4 000 bp.Analysis revealed that 2 964 differentially expressed genes(DEGs)were identified in the browning leaf samples,of which,2 054 were up-regulated expressed and 910 were downregulated expressed.GO enrichment analysis showed that the DEGs were mainly focused on the pathways of metabolic processes,oxidative stress response and catalytic activity.KEGG enrichment analysis found that the DEGs were mainly involved in pathways related to anthocyanin bio-synthesis such as phenylpropanoid biosynthesis and flavonoid biosynthesis.It was further discovered that the expression of the genes related to anthocyanin synthesis pathways such as CHS,PAL,4CL and F3H was in-creased,and might be regulated by transcription factor genes AP2/ERF,MYB,WRKY and NAC that respon-ding to high light,suggesting that they might be the key genes during high light leading to leaf browning in'Xi Shi'.The results of this study could provide the theoretical basis for breeding high light tolerant varieties of Dioscorea opposita in the future.