小麦叶片非顺序和顺序衰老数字基因表达谱分析

Digital gene expression profiling analysis of wheat leaf sequential and non-sequential senescence

【目的】从转录水平揭示小麦叶片顺序和非顺序衰老的形成机制及其在小麦生产中的应用价值。【方法】以顺序衰老小麦(NR9405)和非顺序衰老小麦(温麦19)为材料,应用数字基因表达谱技术对两种衰老类型小麦旗叶在扬花后25 d、30 d和32 d的基因表达量进行检测,筛选花后25 d和30 d,30 d和32 d旗叶的差异表达基因,并对差异表达基因进行GO富集分析。【结果】顺序衰老小麦NR9405花后25 d与30 d相比,差异表达基因共计6659个,其中上调表达基因3404个,下调表达基因3255个;花后30 d与32 d相比,差异表达基因共计4058个,其中上调表达基因3017个,下调表达基因1041个。非顺序衰老小麦温麦19花后25 d与30 d相比,差异表达基因共计13609个,其中上调表达基因7454个,下调表达基因6155个;花后30 d与32 d相比,差异表达基因共计6321个,其中上调表达基因2669个,下调表达基因3652个。上调基因显著富集的主要GO条目有:环境胁迫响应、脂肪酸α-氧化、细胞死亡、DNA分解代谢、自噬、水解酶、转移酶、转运、丝氨酸/苏氨酸蛋白磷酸酶等。下调基因显著富集的GO条目有:光合作用、光的捕获、光合电子传递链、叶绿素生物合成过程、叶绿体机体等。在小麦叶片非顺序衰老过程中,自噬、海藻糖生物合成过程、海藻糖磷酸酶、蔗糖合成酶等相关基因极显著上调表达,有利于保持叶片水分,促进叶片碳氮的转运,提高小麦产量。【结论】小麦叶片的非顺序衰老与自噬、水解酶和丝氨酸/苏氨酸蛋白磷酸酶基因的极显著上调表达密切相关。

【Objective】The formation mechanism and application value in wheat production of wheat leaf sequential and non-sequential senescence were revealed from transcriptional level.【Method】The gene expression levels in flag leaves of two senescence types of wheat at 25 d,30 d and 32 d after flowering were detected by digital gene expression profiling technology,and differentially expressed genes between 25 d and 30 d as well as between 30 d and 32 d after flowering were screened and analyzed by GO enrichment.【Result】In sequential senescence wheat of NR9405 between 25 d and 30 d after flowering,there were 6659 differentially expressed genes,of which 3404 were up-regulated and 3255 were down-regulated.Between 30 d and 32 d after flowering,there were 4058 differentially expressed genes,including 3017 up-regulated genes and 1041 down-regulated genes.In non-sequential senescence wheat of Wenmai 19 between 25 d and 30 d after flowering,the total number of differentially expressed genes was 13609,of which 7454 were up-regulated and 6155 were down-regulated.Between 30 d and 32 d after flowering,the number of differentially expressed genes was 6321,of which 2669 were up-regulated and 3652 were down-regulated.The GO terms with significantly enriched up-regulation genes included response to stress,fatty acid oxidation,cell death,DNA catabolic process,autophagy,hydrolase activity,transferase activity,transport activity,and serine/threonine protein phosphatase activity.The GO terms significantly enriched down-regulation genes included photosynthesis,light harvesting,photosynthetic electron transport chain,chlorophyll biosynthesis processes,and chloroplast.During non-sequential senescence of wheat leaves,autophagy,trehalose biosynthesis,trehalose phosphatase activity and sucrose synthase activity were significantly up-regulated,which were beneficial to maintain leaf water,promote leaf carbon and nitrogen transport,and increase wheat yield.【Conclusion】The non-sequential senescence of wheat leaves was closely related to significant up-regulation of autophagy,hydrolase and serine/threonine protein phosphatase genes.