《植物生理学报》 2016, 52(10): 1481-1490

珙桐种子败育相关基因CesA的克隆及表达分析

熊亚丽, 曹福祥, 刘志明, 董旭杰, 李萌^*

中南林业科技大学生命科学与技术学院, 长沙410004

通信作者：李；E-mail: limeng0422@foxmail.com

摘　要：

严重的种子败育是影响珙桐自然繁殖的重要原因之一, 调控种子败育的分子机制及关键基因目前尚不清楚。根据本研究小组前期获得的珙桐种子转录组数据, 筛选到22个转录本, 分属14个纤维素合酶CesA编码基因, 所有转录本在败育种子中均呈现上调表达趋势。分析珙桐种子中的纤维素含量发现, 正常种子在发育过程中纤维素含量持续升高, 而在败育种子中纤维素含量显著高于正常种子。挑选4个在败育种子中显著上调的CesA基因进行qPCR分析, 结果表明它们表达模式相似, 在败育种子中表达量均显著高于正常种子, 且在正常种子发育后期上调表达。挑选其中表达差异最显著的c43681.graph_c0进行克隆获得882 bp片段。经序列比对, 其编码产物包含292个氨基酸, 与拟南芥纤维素合酶CesA4同源性最高。分析c43681.graph_c0在珙桐不同组织中的表达量发现, 该基因在茎中表达量较低, 而在果肉中表达量较高, 在败育种子中表达量显著高于其它组织。本研究筛选到的c43681.graph_c0可能是一个在珙桐生殖器官中调控纤维素合成的关键基因。

关键词：珙桐; CesA基因; 种子败育; 发育; 表达模式

收稿：2016-06-07   修定：2016-09-07

资助：中南林业科技大学博士科研基金(0490016)和中南林业科技大学青年基金(QJ201512)。

Cloning and expression analysis of CesA genes involved in seed abortion in dove tree (Davidia involucrata)

XIONG Ya-Li, CAO Fu-Xiang, LIU Zhi-Ming, DONG Xu-Jie, Li Meng^*

College of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China

Corresponding author: Li Meng; E-mail: limeng0422@foxmail.com

Abstract:

Serious seed abortion is one of the important factors which restrict the sexual reproduction of dove tree (Davidia involucrata). However, the molecular mechanisms and key genes involved in seed abortion remain unclear. According to the transcriptome data of D. involucrata seed previously obtained by our group, 22 transcripts, belong to 14 CesA genes were selected due to all 22 transcripts showed up-regulated expression in the abortive seeds. We measured the content of cellulose in D. involucrata seeds and found that the cellulose content continuously increased in normal seeds during development processes, and the cellulose content was significantly higher in abortive seeds than that in normal seeds. We selected 4 CesA genes and detected their expression patterns by qPCR. Consistently, the transcript abundance of these genes were significantly greater in abortive seeds than those in normal seeds, and gradually increased during the development of normal seeds. ADEG (differentially expressed gene), c43681.graph_c0, was selected and its 882 bp fragment was cloned. The encoding product of c43681.graph_c0 contains 292 amino acids and was highly homologous to identified cellulose synthase CesA4 in Arabidopsis. The expression levels of c43681.graph_c0 in different tissues of D. involucrate were analyzed and the results showed it had greater transcript abundance in pulp than in stems, while the transcript abundancein abortive seeds was significantly higher than other tissues. It is assumed that c43681.graph_c0 plays a key role in cellulose synthesis in reproductive organs and subsequently regulates seed abortion in D. involucrata.

Key words: dove tree (Davidia involucrata); cellulose synthase genes; seed abortion; development; expression patterns