外源激素对灰霉菌胁迫下月季花器官生理生化指标的影响

Effects of exogenous hormones on the physiological and biochemical indexes of Rosa chinensis‘Pallida’flower organs under Botrytis cinerea stress

【目的】由灰霉菌引起的月季灰霉病是月季采后危害最严重的真菌性病害。据统计由灰霉病造成的月季采后损害在30%~70%,严重制约了月季产业的发展。因此,探索月季花器官对灰霉病的抗性机制,了解月季切花对灰霉菌胁迫的适应性具有重要意义。【方法】利用酶联免疫试剂盒测定感染灰霉菌的月季花器官超氧化物歧化酶(SOD),过氧化物酶(POD),几丁质酶(CHT),多酚氧化酶(PPO)和β-1,3葡聚糖酶(β-1,3-GA)活性随时间的变化情况;并对其PPO、POD和GLU合成关键酶RcPPO,RcPOD和RcBGLU的基因表达量进行分析;最后利用茉莉酸(JA),脱落酸(ABA),水杨酸(SA),2,4表油菜素内酯(BR)和1-氨基环丙烷-1-羧酸(ACC)5种外源激素作为诱导剂,测定月季花器官5种酶活性在不同激素处理后灰霉菌胁迫下的变化情况。【结果】在灰霉菌胁迫下,月季花器官PPO、GLU和POD活性呈持续显著上升趋势,CHT活性在60 h后显著升高,SOD活性呈持续显著下降的趋势;RcPPO,RcPOD和RcBGLU基因表达量持续显著升高;月季花器官经JA和BR处理灰霉菌胁迫后PPO和GLU活性持续显著升高(P<0.05),ACC处理能持续显著增高其CHT活性,ABA和SA处理能在灰霉菌侵染前期显著增强其POD活性,并显著降低其SOD活性。对5种酶活性的Pearson相关性分析结果显示,SOD和其他4种酶活性呈负相关。【结论】外源BR、JA和ACC通过直接诱导PPO,CHT和GLU活性的变化增强月季花器官抗灰霉病的能力,外源ABA和SA则能够降低SOD活性,提高POD活性。本研究为今后研究月季花器官对灰霉菌的抗性机制和防治方法提供了理论基础。

【Objective】Gray mold disease caused by Botrytis cinerea was the most serious fungal disease of Rosa chinensis after harvest.According to statistics,the post-harvest damage of R.chinensis caused by gray molds was between 30%-70%,which seriously restricts the development of R.chinensis industry.Therefore,it was important to explore the resistance mechanism of the flower organs of R.chinensis to B.cinerea and to understand the adaptability of its cut-flowers to B.cinerea stress.【Method】Changes in the activities of superoxide dismutase(SOD),peroxidase(POD),chitinase(CHT),polyphenol oxidase(PPO)andβ-1,3 glucanase(β-1,3-GA)were investigated over time in the flower organs of R.chinensis infected B.cinerea.The relative expression of the key enzyme genes including RcPPO,RcPOD and RcBGLU for the synthesis of PPO,POD and GLU was analyzed.Five exogenous hormones including Jasmonic acid(JA),abscisic acid(ABA),salicylic acid(SA),2,4-epibrassinolide(BR)and 1-aminocyclopropane-1-carboxylic acid(ACC),were used as inducers to determine the changes of the activities of five enzymes in R.chinensis flowser organs under B.cinerea stress after different hormone treatments.【Result】The activities of PPO,GLU and POD of R.chinensis flower organs increased significantly,the activities of CHT increased significantly after 60 h of inoculation with B.cinerea,while the activities of SOD decreased significantly under B.cinerea stress.The gene expressions of RcPPO,RcPOD and RcBGLU increased significantly with the extension of infection time.PPO and GLU activities were increased by JA and BR treatments,the CHT activity was significantly increased by ACC treatment,the POD activity was significantly increased and the SOD activity was significantly decreased in the pro-infestation period of B.cinerea by ABA and SA treatments.The Pearson correlation analysis of the five enzyme activities showed a negatively correlation between SOD and the other four enzyme activities.【Conclusion】Exogenous BR,JA and ACC could enhance the resistance of R.chinensis flower organs to B.cinerea by directly inducing changes in the activities of PPO,CHT and GLU.While exogenous ABA and SA could reduce the SOD activity and increase the POD.