甘蔗应答黑穗病菌侵染相关酶活性和内源激素含量的变化

Changes of related enzyme activity and endogenous hormone content in sugarcane response to smut fungus infection

【目的】研究不同甘蔗品种与黑穗病菌长期互作过程中相关酶活性及内源激素含量的变化,为甘蔗应答黑穗病菌侵染的抗性机制提供理论依据。【方法】选用抗黑穗病品种桂糖29号和感黑穗病品种崖城71-374,用浸渍法接种黑穗病菌,对照组用无菌水模拟接菌。在接菌后30、60、90和180 d取甘蔗+1位叶为样品,分析几丁质酶、β-1,3-葡聚糖酶和过氧化氢酶(CAT)活性及生长素(IAA)、细胞分裂素(CTK)和乙烯(ETH)含量的变化。【结果】在整个侵染期间,两个甘蔗品种叶片的几丁质酶活性、β-1,3-葡聚糖酶活性及IAA、CTK含量呈逐步降低或波动下降趋势,均在接种后180 d达最低值,而CAT活性整体上呈上升趋势,在接种后180 d达最高值;其中抗性品种桂糖29号的β-1,3-葡聚糖酶活性和ETH含量在整个浸染过程均高于感病品种崖城71-374。【结论】甘蔗在不同时期应答黑穗病菌胁迫的生理生化反应不同,感病品种与抗病品种的防御机制可能存在差异。

【Objective】The changes of related enzyme activities and endogenous hormone contents in different sugarcane varieties during the long term interaction with smut fungus were studied to provide theoretical basis to illustrate the resistance mechanism of sugarcane to smut fungus infection.【Method】The smut-resistant variety GT29 and the smut-susceptible variety Yacheng 71-3744 were selected to be inoculated with smut fungus by dipping method;the control group was treated with sterile water to conduct simulated inoculation with fungus.Sugarcane+1 leaf samples were taken at 30,60,90 and 180 d respectively after the inoculation treatment,the changes of chitinase,β-1,3-glucanase and catalase(CAT)activities,and auxin(IAA),cytokinin(CTK)and ethylene(ETH)contents were analyzed.【Result】During the entire infection period,activities of chitinase andβ-1,3-glucanase and contents of IAA and CTK the two sugarcane varieties leaves showed the trends of gradual decrease or fluctuating decrease,and they reached the lowest level 180 d after inoculation.But the activity of CAT showed an increasing trend and reached the highest level 180 d after inoculation.β-1,3-glucanase activity and ETH content in the smut-resistant variety GT29 were always higher than those in the smut-susceptible variety Yacheng 71-3744 during the whole infection period.【Conclusion】Physiological and biochemical responses of sugarcane to smut fungus stress are different at different growth stages,which may reflect different defense mechanisms between the susceptible variety and the resistant variety.