Tsuji Hiroyuki, Tsutsumi Nobuhiro, Sasaki Takuji, Hirai Atsushi, Nakazono Mikio
Laboratory of Plant Molecular Genetics, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Gene. 2003 Feb 27;305(2):195-204. doi: 10.1016/s0378-1119(03)00383-4.
Recent studies have suggested that mitochondrial aldehyde dehydrogenase (aldehyde:NAD(P)(+) oxidoreductase, EC 1.2.1.3) (ALDH2) plays essential roles in pollen development in plants. Rice (Oryza sativa L.) ALDH2 is encoded by at least two ALDH2 genes, one of which (ALDH2a) was previously identified. In this study, to understand the roles of ALDH2 in rice, we isolated and characterized a cDNA clone encoding another rice ALDH2 (ALDH2b). An in vitro ALDH assay indicated that ALDH2b possesses an NAD(+)-linked activity for oxidation of acetaldehyde, glycolaldehyde and propionaldehyde. Northern blot and immunoblot analyses revealed that ALDH2b was constitutively present in all the organs examined, whereas ALDH2a was expressed in leaves of dark-grown seedlings and panicles. By RFLP linkage mapping, the ALDH2a and ALDH2b genes were mapped to the long arm of chromosome 2 and the short arm of chromosome 6, respectively. We suggest that the rice ALDH2a and ALDH2b genes are orthologues of maize mitochondrial ALDH genes, rf2b and rf2a, respectively.
最近的研究表明，线粒体乙醛脱氢酶（醛：NAD(P)(+)氧化还原酶，EC 1.2.1.3）（ALDH2）在植物花粉发育中起着至关重要的作用。水稻（Oryza sativa L.）的ALDH2至少由两个ALDH2基因编码，其中一个（ALDH2a）先前已被鉴定。在本研究中，为了了解ALDH2在水稻中的作用，我们分离并鉴定了一个编码另一种水稻ALDH2（ALDH2b）的cDNA克隆。体外ALDH测定表明，ALDH2b具有NAD(+)连接的活性，可氧化乙醛、乙醇醛和丙醛。Northern印迹和免疫印迹分析显示，ALDH2b在所有检测的器官中均组成性存在，而ALDH2a在黑暗生长的幼苗叶片和穗中表达。通过RFLP连锁图谱分析，ALDH2a和ALDH2b基因分别定位于第2染色体的长臂和第6染色体的短臂。我们认为，水稻ALDH2a和ALDH2b基因分别是玉米线粒体ALDH基因rf2b和rf2a的直系同源基因。
