关键词: 小麦, LEA3, 基因家族, 赤霉病, 表达谱

Abstract: Late embryogenesis abundant (LEA) proteins are a class of proteins accumulating in seeds during the late stage of embryonic development in higher plant, and they play  important roles in plant resistance to adversity stress. LEA3, the third group of the LEA proteins, is the major member of this family and has been extensively studied for its excellent performance in drought and salt tolerance in plants. In previous study, a differential accumulation protein Wrab17 (TaLEA3 gene family) associated with Fusarium head blight (FHB) resistance was screened from wheat cobs inoculated with Fusarium graminearum   by high-throughput proteomics strategy. In order to reveal the sequence characteristics of TaLEA3 gene family in wheat and its response mechanism to biological stress, bioinformatics method was used to systematically study the gene family. The results showed that a total of 26 TaLEA3 genes were present in wheat genome named TaG3LEA-1~TaG3LEA-26, which were distributed on nine chromosomes of wheat. Tandem duplication and segmental duplication were probably the main expansion ways of this gene family. And MEME analysis showed that the members of this family contained either motif 2 or motif 5, which is the typical feature of LEA3 family. Through expression profiling analysis and qRT-PCR verification, TaG3LEA-25 was highly expressed under both drought and high temperature stresses, and there was also a significant difference in FHB inoculation test, suggesting that it might be involved in FHB resistance. The results of this study provided valuable information for elucidation of the evolutionary relationships of TaLEA3 gene family in wheat and laid a theoretical foundation for further exploration of their functional mechanisms.

Key words: wheat, LEA3, gene family, Fusarium head blight, expression profile