云南栘[木衣]对重度干旱胁迫的生理响应和转录组分析OA

Docynia delavayi is a high-quality eco-economic tree species with outstanding drought toler-ance.To investigate the dynamic responses and regulatory mechanisms of physiological indicators in Docynia delavayi under severe drought stress,seedlings of Docynia delavayi were treated with 45％PEG-6000 to simulate severe drought stress.Physiological indicators,including osmoregulatory sub-stance contents and antioxidant enzyme activities,were measured.Transcriptome sequencing was con-ducted to screen differentially expressed genes(DEGs),and GO and KEGG enrichment analyses were performed to identify the enriched pathways of DEGs.Based on the enrichment results and gene ex-pression patterns,key drought resistance genes and important transcription factor members were screened,and their drought-induced expression patterns were examined.Drought stress significantly increased the soluble sugar and malondialdehyde(MDA)contents in Docynia delavayi,while the chlorophyll content decreased.Transcriptome analysis revealed a total of 10 814 DEGs common to all three comparison groups,which were significantly enriched in the categories of biological process,cellular compo-nent,and molecular function.KEGG analysis showed that key pathways such as plant hormone signal trans-duction and the plant MAPK signaling pathway were gradually shut down with prolonged drought treatment.Finally,based on the enrichment results,six proline-related DEGs,90 antioxidant system-related DEGs,and 20 key transcription factors were screened.Expression pattern analysis revealed that these genes exhibited dif-ferent expression trends.Taken together,these results preliminarily suggested that the differential expression trends of antioxidant enzyme genes were attributable to the regulation of the antioxidant system,and that plants could compensate for insufficient expression of certain genes by enhancing the expression of key genes to efficiently respond to drought stress.