拟南芥响应NO突变体的筛选及遗传分析

Screening and Genetic Analysis of Nitric Oxide Sensitive Mutant in Arabidopsis thaliana

从甲基磺酸乙酯(EMS)诱变获得的拟南芥突变体库中筛选对一氧化氮(NO)胁迫敏感的突变体,以期为研究信号分子NO在植物中的分子调控机制提供遗传材料。从EMS诱变获得的拟南芥突变体库中筛选得到1株对NO敏感的突变体nsm1(nitric oxide sensitive mutant 1),在正常生长条件下,突变体nsm1与野生型拟南芥的表型并没有明显区别,但是对NO胁迫的敏感性明显高于野生型拟南芥,在50μmol/L SNP(NO供体)处理下,野生型拟南芥的相对根长(与在正常生长的根长比值)为50.8%,而突变体nsm1的相对根长为22.4%。进一步研究发现,突变体nsm1对甘露醇模拟的干旱胁迫敏感,在100 mmol/L甘露醇处理下,野生型拟南芥的相对根长为83.4%,而突变体nsm1的相对根长仅为45.7%,这可能与突变体nsm1的失水率、水势、气孔导度和蒸腾速率高于野生型拟南芥有关。遗传学分析表明,该突变体为单基因隐性突变。

In order to investigate the molecular regulation mechanism of nitric oxide in Arabidopsis,we screened nitric oxide（ NO）-sensitive mutants from an EMS mutant library in the plants. As a result,nsm1 mutant（ nitric oxide sensitive mutant 1） was screened from this library. Mutant nsm1 was sensitive to nitric oxide though there was no obvious difference of phenotype between the mutant and wild type under normal growth conditions. Under 50 μmol/L SNP treatment,the relative root length of wild type（ compared with root length in normal growth） was 50. 8%,while the relative root length of mutant was 22. 4%. Further study found that mutant nsm1 was sensitive to drought stress simulated by mannitol. Under 100 mmol/L mannitol treatment,the relative root length of wild type was 83. 4%,while the relative root length of mutant was45. 7%. It possibly related with high dehydration rate,water potential,stomatal and transpiration rate in mutant nsm1. Genetic analysis suggested that nsm1 was a single recessive mutant.