Transcriptomic Analysis of Maize Silks in Response to Drought Stress
To investigate the molecular response to drought stress of silks,two treatments with soil moisture content of 80%field holding capacity(CK)and 60%field holding capacity(DS)were set up using Annong 591 and Xianyu 335,and the maize silks were sampled during the rapid increase in silk elongation,and transcrip-tome sequencing was performed.By comparing the gene expression differences between the drought and control groups of the two varieties,the key pathways and related candidate genes of maize silks in response to drought were clarified.The results showed that the phenylpropane biosynthesis pathway(ko00940)and starch and su-crose metabolism pathway(ko00500)were the key pathways in maize silk response to drought.In the phenylpro-pane biosynthetic pathway 4 CL,CCR,CAD and POD genes were lowly expressed in drought-prone maize silks.Correlation analysis showed that down-regulation of 4 CL,CCR,CAD and POD genes was associated with reduced lignin content.Converting enzyme and sucrose synthase genes in the starch and sucrose metabolic pathways were lowly expressed in drought maize silks.Correlation analysis indicated that down-regulation of convertase and su-crose synthase genes was associated with sucrose metabolism.In summary,this study identified key genes and me-tabolites involved in sucrose and lignin metabolism.The lignin synthesis are associated with drought tolerance in maize silks,and 4CL,CCR,CAD,and POD are the candidate genes for drought tolerance in maize silks.In addi-tion,the starch and sucrose metabolic pathways are associated with silk elongation and drought tolerance of silks,and invertase and sucrose synthase are the main candidate key enzymes.
MaizeSilksDrought stressTranscriptomePhenylpropanoid biosynthesisStarch and sucrose metabolism