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光合途径的一个分离得到了编码高梁(Sorghum vuklgare L.)C4型NADP-ME的全长cDNA.该cDNA全长为2 139 bp,其开放可读框为1 911bp,共编码636个氨基酸和一个终止密码子(GenBank登录号为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 C4 Type NADP-ME

The gene encoding sorghum NADP malic enzyme, which plays a key role in C₄ photosynthetic pathway, was isolated by RT-PCR and cDNA library screening. The 2 139 bp cDNA sequence obtained includes a 1 911-bp open reading frame that encodes 636 amino acids and a terminating codon (GenBank accession 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 all confirmed the effective expression of sorghum (Sorghum vulgare L.) C₄ type NADP-ME in rice, with the enzyme activity being elevated 1–7 folds. However, no appreciable change was demonstrated in carbon assimilation of the transgenic rice though increased photoinhibition was noted under high light intensity.