玉米茉莉酸甲酯不敏感突变体的筛选

摘要

The phytohormone jasmonate plays a pivotal role in plant systematic resistance to herbivores attack as a long-distance mobile signal. To demonstrate the Jasmonic acid (JA) signal pathway and the insect-resistant mechanism in maize, we utilized an improved approach to screen the maize mutants associated with JA signal pathway, which will be available for further research. The 6118 lines’ seeds from EMS-mutagenic maize mutants library were cultivated in the medium containing the exogenous MeJA. The different tolerances of the mutants to MeJA were identified by observing the growth of maize roots. When the final concen-tration of MeJA was 50 µmol L–1, 61 MeJA-insensitive mutants with tolerance Grade I were obtained in the primary screening experiment. When the final concentration of MeJA was 100 µmol L–1 or 200 µmol L–1, 37 and 10 tolerant events were gained in the confirmation experiments, respectively. Then, we analyzed the heredity of M1 seeds tolerant to MeJA. The results showed that the tolerance of the mutants to MeJA was hereditable. The MeJA-insensitive mutants associated with JA regulation pathway are the potential materials for the further studies of JA signal pathway and insect resistant mechanism in maize.%植物激素茉莉酸(jasmonic acid, JA)作为一种可以长距离运动的信号分子在植物对昆虫侵害的系统抗性中起核心调控作用。为了解析玉米 JA 信号途径及抗虫机制,本研究利用改进的玉米突变体的筛选方法,筛选与 JA 信号途径相关的突变体用于下一步的研究。将甲基磺酸乙酯(ethyl methane sulfonate, EMS)诱变的玉米突变体库6118份种子分别置含有外源茉莉酸甲酯(methyl jasmonate, MeJA)的培养基中培养,通过观察玉米根系的生长情况,确定对MeJA的不同耐受性。当MeJA终浓度为50µmol L–1时,初步筛选到对MeJA不敏感的I级耐受性突变体61株；当MeJA终浓度分别为100µmol L–1和200µmol L–1时进行验证,得到的耐受性事件分别为37株和10株。对自交收获的子一代遗传性分析表明,这些突变体对 MeJA 表现出的耐受性具有可遗传性。筛选获得的对 MeJA 不敏感突变体可能与JA调控有关,是研究玉米JA信号途径的很好材料。