水稻温度超敏突变体ths1的鉴定和基因定位

Characterization and gene mapping of a temperature hyper-sensitive mutant ths1 in rice

从籼稻品种‘Kasalath’甲基磺酸乙酯(ethyl methanesulfonate,EMS)诱变突变体库中筛选到一个温度敏感突变体ths1(temperature hyper-sensitive 1)。与野生型相比,突变体ths1的主根伸长和侧根发育对温度变化非常敏感:在30°C条件下ths1表型与野生型一致;在温度低于26°C时,ths1主根变短,侧根缺失。在低温(24°C)条件下ths1侧根原基停留在原基起始阶段,根尖ROS含量显著高于野生型。遗传分析显示,ths1表型由半显性单基因控制。利用F2群体对ths1基因进行定位,将突变基因定位在第1染色体长臂着丝粒附近C01M14到RM11110两个标记之间的694 kb区间。研究结果为进一步克隆THS1基因,揭示植物感受外界温度变化的分子生理机制奠定基础。

A temperature hyper-sensitive mutant thsl （temperature hyper-sensitive 1） was isolated from a rice EMS （ethyl methanesulfonate, EMS）-generated mutant library （＇Kasalath＇, indica）. The development of prima- ry root and lateral roots of thsl mutant showed hyper-sensitive to temperature changes. The phenotype of thsl mutant was consistent with wild-type at 30℃, but under the condition of temperature below 26℃, the primary root of thsl mutant was shorter and the lateral roots growth was inhibited compared with the wide type. The de- velopment of lateral roots of the mutant was inhibited at the initial stage of primordium, and the ROS content in root tip of thsl mutant was significantly higher than wild type when cultured at low temperature （24℃）. Genet- ic analysis showed that thsl possessed a semi-dominant mutation in a single nuclear locus. F2 population was constructed by crossing the mutant with ＇Nipponbare＇, and the mutants from extreme individuals were selected to map gene thsl. The gene was located in the 694 kb region near the centromere between the molecular mark- ers C01M14 and RMllll0 on the long arm of chromosome 1. The results of this study lay a foundation for fur- ther cloning THS1 gene and revealing the molecular mechanism of plant perception and response to tempera- ture.