Analysis of transcriptome differences between two tropical maize inbred lines planted under long sunshine

【Objective】The differentially expressed genes(DEGs)among different photosensitive inbred lines were explored,so as to provide a theoretical basis for revealing the variation mechanism of photoperiod sensitivity of tropical maize germplasm and a new way of improving tropical maize germplasm by molecular assisted method.【Method】 Tropical germplasm light-insensitive inbred lines of QR273 and light-sensitive inbred line of T32 were used as test materials, which were planted under artificial control conditions of long-days(LD)treatment(16 h light/8 h dark). In the four leaf stage,young leaves were gathered,and their total RNA was extracted. The transcriptome sequencing of different photosensitive inbred lines was carried out by RNA-Seq technology. At the same time,combined with bioinformatics analysis,the DEGs among different photosensitive inbred lines were screened.【Result】Under LD conditions,a total of 6977 genes showed differentially expression between lines of T32 and QR273,of which 3291 genes showed up-regulated expression in T32 and 3686 genes showed downregulated expression in T32. GO functional annotation analysis showed that 24 genes responding to light stimulation and radiation showed significant differences in T32 and QR273 and that there were 17 DEGs related to response to light stimulation and radiation, post embryonic development,photoperiod,reproductive structure development,reproductive system development,reproductive development process,photoperiod or flowering and meristem vegetative to reproductive growth. Enrichment analysis of KEGG signaling pathway showed genes related to circadian rhythm pathway had significant differences in expression between T32 and QR273. The expression of Zm00001e030377 and Zm00001e023792 genes in T32 was higher than that in QR273,while the expression of Zm00001e016746 and Zm00001e011193 genes in T32 was lower than that in QR273.【Conclusion】 A total of 6977 DEGs are identified by transcriptome difference analysis between photo-sensitive and light-insensitive tropical maize inbred lines under long sunshine conditions,of which 24 DEGs involved in response to light stimulation and radiation,and 17 DEGs related to response to light stimulation,radiation,post embryonic development,photoperiod and the transformation from vegetative growth to reproductive growth of meristem,and 15 DEGs related to circadian rhythm pathway. These genes may be the genetic factors leading to the significant differences in photoperiod sensitivity variation among tropical maize germplasms.