甜菜碱参与西瓜抗枯萎病的初步探究

Preliminary Study of Betaine Mediated Resistance Against Fusarium wilt in Watermelon

为探究甜菜碱在参与西瓜抗枯萎病方面的作用,本研究以西瓜悬浮细胞为试验材料,利用镰刀菌酸诱导,测定细胞活性氧(ROS)的变化情况以及甜菜碱合成相关基因的表达变化等。结果表明:镰刀菌酸对西瓜细胞的生长有明显的抑制作用,通过外源添加甜菜碱可以缓解低浓度(≤100μmol/L)下镰刀菌酸的胁迫;通过镰刀菌酸诱导西瓜细胞,可以使细胞内ROS迅速升高,并在30 min达到最大值,而同时添加甜菜碱处理可以明显降低细胞ROS含量;此外,镰刀菌酸诱导可以使甜菜碱合成基因Cl BADH和Cl CMO基因表达量呈现先上升后缓慢下降的趋势,且0.5 h相对表达量达到最高,这证明镰刀菌酸对西瓜甜菜碱合成基因Cl BADH和Cl COM的表达有不同程度诱导作用。上述研究结果初步表明甜菜碱在参与西瓜抗枯萎病方面具有一定作用,为加强对西瓜枯萎病抗病机制的探索和发掘抗性相关基因提供了理论支持。

To explore the effectivity of betaine against Fusarium wilt in watermelon, the change of reactive oxygen species （ROS） and the expression of betaine biosynthesis genes were determined after the suspension cells of watermelon elicited by fusaric acid. The results showed that the fusaric acid had significant inhibition on the growth of watermelon cells, but exogenous betaine could alleviate the stress accordingly. Elicition watermelon cells by Fusarium acid could rapidly raise the ROS content and ROS content culminated at 30 min. Whereas the exogenous betaine could decrease the ROS obviously. Gene expression of both ClBADH and CICMO after inducted by fusaric acid increased and the expression level reached the maximum at 0.5 h which indicated that betaine could be induced against fusaric acid. The above results showed that betaine might be involved in the resistance reinforcement against Fusarium wilt. The study would lay a foundation for further research and meanwhile provide a theoretical support for exploring the mechanism of resistance and foridentificating resistance related genes against Fusarium wilt in watermelon.