受光诱导的水稻突变体spl41的抗病鉴定及生理指标测定

Identification of Disease Resistance and Determination of Physiological Characteristics of Rice Mutant Spl41 Induced by Light

为进一步研究水稻类病变突变体spl41的形态生理特征以及类病斑产生的原因和抗病性,对突变体spl41的种子进行表型观察和胚乳成分测定;同时对突变体spl41的叶片进行了遮光处理和接种病原菌实验,并测定了与活性氧(ROS)相关以及抗病相关的酶活。实验结果表明,突变体spl41的颖壳上具有红褐色斑点,但胚乳上无斑点。突变体spl41单株结实粒数较野生型HHZ降低了80%。此外,突变体spl41胚乳中的可溶性糖和可溶性蛋白含量分别较野生型HHZ下降了37.27%和13.89%,表明spl41突变体植株中胚乳的发育受到了影响。光可以诱导突变体spl41类病斑的产生,同时伴随着H_(2)O_(2)的累积。spl411突变体对稻瘟病菌生理小种GUY11、Y34和细菌性条斑病菌生理小种RS105具有广谱抗病性。spl41突变体叶片中CAT、POD、SOD的活性及MDA的含量显著高于野生型HHZ,说明ROS清除机制在spl411突变体中受到干扰,导致细胞受损和ROS的爆发;同时,PAL和PPO的活性在spl41突变体叶片中也显著高于野生型HHZ,这结果积极地响应了突变体spl41的抗病表型。

In order to investigate the physiological and disease resistance characteristics of rice lesion mimic mutant spl41, the seed phenotype, endosperm development, the effects of light on lesion generation, as well as disease resistance were observed and measured in spl41 mutant. Our results showed that reddish brown lesions also appeared on husks in the seeds of spl41, but not on the endosperm. The amount of seeds in spl41 mutant was 80%less compared to wild-type rice variety HHZ. Besides, the contents of soluble sugar and soluble protein in the endosperm of spl41 decreased by 37.27% and 13.89%, respectively, compared to HHZ. These results indicated that the endosperm development was affected in lesion mimic mutant spl41. Furthermore, we found the initiation of lesion was induced by light and accompanied with H_(2)O_(2) accumulation in leaves. We also found that spl41 was resistant to rice blast fungus isolate GUY11 and Y34, as well as bacterial leaf streak isolate RS105. The activities of CAT, POD, SOD and the content of MDA in spl41 mutant are all higher than those of in wild-type HHZ, indicating that the ROS clearance mechanism of spl41 was disturbed, resulting in cell damage and ROS burst. The activities of PAL and PPO in spl41 mutant were also higher than those of in wild-type HHZ, which positively respond to the disease resistance of spl41.