水稻线粒体ATP合成酶小亚基基因的鉴定及解析

Identification and Characterization of Mitochondrial ATP Synthase Small Subunit Gene in Rice (Oryza sativa L.)

本研究把碳酸盐 (NaHCO3、Na2 CO3)对植物造成的逆境称为“碳酸盐逆境” (Carbonatestress)。从水稻根cDNA文库中筛选出一些与碳酸盐逆境相关的基因 ,水稻线粒体ATP合成酶 6kDa亚基基因 (简称 :RMtATP6基因 )为其中之一。该基因编码的氨基酸序列与Jansch等人 (1996 )从马铃薯(Solanumtuberosum )线粒体中纯化的线粒体ATP合成酶 6kDa亚基氨基酸序列 (F1F0 ATP合成酶的F0部分 )具有同源性 ,但是这个小蛋白的功能尚不清楚 ,其基因也没有被鉴定。本研究克隆了这个基因(Accessionnumber :AB0 5 5 0 76 ) ,并解析了在碳酸盐逆境胁迫下它的表达特性。RMtATP6基因编码的蛋白预测分子量为 6 5 78kDa ,预测的细胞内存在位置为线粒体膜间间隙 ,结果预示了RMtATP6基因编码的蛋白为水稻线粒体ATP合成酶 6kDa亚基基因。Southern杂交结果表明RMtATP6基因是水稻核基因组中的一个单拷贝基因。通过对RMtATP6基因在植物中的表达特性及在碳酸盐逆境下在酵母中的功能解析 ,表明了该基因与碳酸盐逆境有关。

odium carbonate (NaHCO 3?Na 2CO 3) causing stress for plant is named as "carbonate stress" in this study. Some genes related to carbonate stress were screened from rice root cDNA library, rice mitochondrial ATP synthase 6kDa subunit gene (shortened form: RMtATP6 gene) is one of these genes. The gene encoding amino acids sequence is homology to mitochondrial ATP synthase 6kDa subunit (F 0 part of F 1F 0-ATP synthase) purified from potato (Solanum tuberosum) mitochondrial by Jansch et al. (1996), but the function of this small protein is not clear and the gene has not been identified. In this report, the gene was cloned (accession number: AB055076), its expression was characterized under carbonate stress. The calculated molecular weight of RMtATP6 gene encoding protein is 6.578 kDa, the predicted intracellular localization sites is in mitochondrial intermembrane space. Results suggested that the RMtATP6 gene encoding protein be rice mitochondrial ATP synthase 6kDa subunit. Southern analysis suggested that the RMtATP6 gene be a single-copy gene in rice genomic DNA. Through analyzing the RMtATP6 gene expression in plant and its function in yeast under carbonate stress, the function of RMtATP6 gene is probably related to carbonate stress.