Hsieh H M, Liu W K, Huang P C
Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan.
Plant Mol Biol. 1995 Jun;28(3):381-9. doi: 10.1007/BF00020388.
A novel rice genomic sequence encoding coding segments homologous to other metallothionein-like genes was isolated from Oryza sativa genomic library. This sequence, hereby designated as rgMT (rice genomic metallothionein-like gene), consists of two exons and one intron. From the coding sequence, it is predicted that rgMT encodes one protein of 74 amino acids. Differential expression of rgMT in rice plants was observed as mature transcripts were more abundant in roots than in leaves and sheaths. Under different stress conditions, such as excess heavy metals and heat shock, expression of rgMT was significantly elevated. This was especially noticeable with 250 microM CuCl2 for 16 h, 40 degrees C heat for 2 h and 0.06% DMSO for 1 h. Under sucrose starvation, rgMT transcripts also increased with time up to 72 h. During recovery from sucrose starvation, the transcripts declined slightly within 12 h of recovery. rgMT transcripts were also seen to have increased expression in senescent leaves. These results support the notion that rgMT is a stress-inducible gene in rice heretofore unreported.
从水稻基因组文库中分离出一个新的水稻基因组序列，该序列编码的编码片段与其他类金属硫蛋白基因同源。此序列在此被命名为rgMT（水稻基因组类金属硫蛋白基因），由两个外显子和一个内含子组成。根据编码序列预测，rgMT编码一种含74个氨基酸的蛋白质。观察到rgMT在水稻植株中的差异表达，成熟转录本在根中比在叶和叶鞘中更丰富。在不同的胁迫条件下，如过量重金属和热激，rgMT的表达显著升高。在250微摩尔/升氯化铜处理16小时、40℃加热2小时和0.06%二甲基亚砜处理1小时的情况下，这种情况尤为明显。在蔗糖饥饿条件下，rgMT转录本也随时间增加，直至72小时。在从蔗糖饥饿中恢复的过程中，转录本在恢复的12小时内略有下降。在衰老叶片中也观察到rgMT转录本表达增加。这些结果支持了rgMT是水稻中一个迄今未报道的胁迫诱导基因这一观点。
