稻曲病菌毒素对不同抗病水稻品种生理生化特性的影响

Effects of mycotoxins of Ustilaginoidea virens on physiological-biochemical characteristics of different resistant rice varieties

为了探究稻曲病菌毒素对不同抗病水稻品种生理生化特性的影响,本研究用稻曲病菌粗毒素处理水稻感病品种9311和抗病品种IR28,分析粗毒素对水稻胚根、胚芽和幼苗生长的影响,叶片对毒素的过敏性反应,粗毒素对幼苗的防御酶系活性、可溶性蛋白(SP)以及酯酶(EST)同工酶的影响。结果表明,稻曲病菌粗毒素对抗病和感病品种的胚根、胚芽、幼苗茎和叶生长均有抑制作用,且粗毒素对感病品种9311的抑制作用显著高于抗病品种IR28;粗毒素可引起叶片发生过敏性反应,出现病害症状。在稻曲病菌粗毒素胁迫下,抗病和感病品种幼苗的超氧化物歧化酶(SOD)、过氧化物酶(POD)、苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)活性均较对照有不同程度的升高,其峰值比对照提高了8.79%~34.29%;POD、PAL酶活性先缓慢上升,随着粗毒素的处理时间延长时达到顶峰,后逐渐下降,而SOD、PPO酶活则是先急剧下降后又缓慢上升达到顶峰,后逐渐下降;抗病品种IR28的4种酶活性高于感病品种9311,其峰值高出了17.85%~58.30%,且酶活性峰值出现的时间晚,酶活性降低慢。在稻曲菌粗毒素胁迫下,水稻幼苗SP含量均较对照有不同程度降低,但抗病品种IR28的SP含量高于9311的SP含量,在第5天时达到最高,高出了51.37%,且IR28的SP谱带颜色比9311的SP谱带颜色深。此外,在粗毒素胁迫下,2个品种的EST同工酶谱带随着处理时间的延长而变浅,但IR28的EST同工酶谱带比对应9311谱带颜色深。本研究为促进稻曲病菌毒素在水稻品种抗病性鉴定与抗病育种中的应用提供了科学依据。

To clarify the effects of the mycotoxins of Ustilaginoidea virens on physiological-biochemical characteristics of different resistant rice varieties,the susceptible variety 9311 and the resistant variety IR28 were treated with the crude toxin of U. virens. The effects of toxin on the growth of radicle,germ,seedling stem and leaf,hypersensitive reaction of leaves,defense enzyme activity,soluble protein( SP) and esterase( EST) isozyme of seedling were analyzed. The results showed that the crude toxin of U. virens inhibited the growth of radicle,germ,seedling stem and leaf of resistant and susceptible varieties,with higher inhibitory effect of toxin on susceptible cultivar 9311 than cultivar IR28. The toxin caused hypersensitive reaction in leaves and disease symptom. Under the stress of toxin,the enzyme activities of SOD,POD,PAL and PPO of resistant and susceptible varieties increased by different magnitude compared with the control,and the peak value increased by 8.79%-34.29%. The activities of POD and PAL increased slowly at first,reached the peak along with the extension of toxin treatment time,and then decreased gradually. The activities of SOD and PPO decreased sharply at first and then increased slowly,reached the peak,and then decreased gradually. The activities of four enzyme of the resistant cultivar IR28 were higher than that of the susceptible cultivar 9311,with peak values being 17.85%to 58.30% higher. After treated with mycotoxins,the content of SP in rice seedlings decreased to some extent. The content of SP in cultivar IR28 was higher than that in cultivar 9311,and reached the highest at the fifth day,which was 51. 37% higher in cultivar IR28 than cultivar9311,and the color of SP band of IR28 was darker than that of cultivar 9311. In addition,the EST isozyme bands of the two cultivars became lighter along with the prolongation of treatment time,but the EST isozyme bands of cultivar IR28 were darker than those of cultivar 9311. This study provided scientific basis for the application of mycotoxins of U. virens in identification and breeding for disease resistance cultivar.