转高粱C4型NADP-ME基因水稻植株的光合生理特征

NADP-苹果酸酶(NADP-ME)是C4型植物C4光合途径的一个关键酶。利用RT-PCR结合筛选cDNA文库技术,分离得到了编码高粱(SorghumvulgareL.)C4型NADP-ME的全长cDNA。该cDNA全长为2139bp,其开放可读框为1911bp,共编码636个氨基酸和一个终止密码子(GenBank登陆号为AY274836)。利用农杆菌介导的转化系统将其转入水稻品种“农垦58”。经Southern杂交、Northern杂交和酶活性检测表明,高粱C4型NADP-ME可以在水稻中有效表达,酶活性可被提高1~7倍。对转基因水稻进行光合生理检测表明,转NADP-ME基因水稻CO2交换特征没有明显改变,但是在中午强光条件下光抑制加剧。

Photosynthetic Features of Transgenic Rice Expressing Sorghum C_4 Type NADP-ME

The gene encoding sorghum NADP malic enzyme, which plays a key role in C4 photosyntheticpathway, was isolated by RT-PCR and cDNA library screening. The 2 139 bp cDNA sequence obtainedincludes a 1 911-bp open reading frame that encodes 636 amino acids and a terminating codon (GenBankaccession number: AY274836). It was then introduced into Nongken 58, a rice variety, using an Agrobacterium-mediated system. Southern hybridization, Northern hybridization and enzyme activity determination allconfirmed the effective expression of sorghum (Sorghum vulgare L.) C4 type NADP-ME in rice, with theenzyme activity being elevated 1-7 folds. However, no appreciable change was demonstrated in carbonassimilation of the transgenic rice though increased photoinhibition was noted under high light intensity.