小麦16.9kD热激蛋白cDNA克隆及其表达分析

Cloning and Expression of Ta HSP16.9-1 cDNA in Wheat

为进一步了解小分子量热激蛋白在小麦耐热能力中的作用，根据玉米16.9 kD小分子热激蛋白的氨基酸序列，采用同源序列法进行序列拼接和引物设计，用RT-PCR扩增获得了1个源自小麦叶片的热激蛋白基因cDNA片段，即TaHSP16.9-1（GenBank登录号为EU649679）。TaHSP16.9-1全长770 bp，5′非翻译区81 bp，3′非翻译区233 bp，开放阅读框编码151个氨基酸。序列分析结果表明，此蛋白与已知单子叶植物来源的同类基因高度同源，相似性介于78.3%-96.7%之间。定量RT-PCR表达谱分析显示，TaHSP16.9-1在小麦抽穗期的茎和旗叶以及幼苗期叶片中均能表达，其在小麦幼苗叶片中的表达受高温胁迫的诱导。

Using maize low molecular weight heat shock protein （GenBank accession No. CAA46641） amino acid sequence as a querying probe, many highly homologous EST sequences were obtained from GenBank and a putative cDNA sequence of wheat （Triticurn aestivurn L. ） was assembled. Futhermore, a wheat 16. 9 kD HSP gene cDNA, named as TaHSP16. 9-1 （GenBank accession number EU649679） was cloned. TaHSP16.9-1 was 756 bp in full length, including 5＇ untranslated region of 82 bp, 3＇ untranslated region of 218 bp, and an open reading frame （ORF） encoding 151 amino acids. Homology analysis showed that the deduced amino acid sequence of TaHSP16.9-1 shared 78.3- 96.7% identity with 16. 9 kD HSP from other monocotyledon. Quantity RT-PCR analysis showed that the TaHSP16.9-1 was expressed in mature wheat stems, immature spikes and immature leaves. The expression profiling also showed that TaHSP16.9-1 expression was up-regulated by heat shock in wheat seedlings.