彭家丽　赵虎　李智佳　彭梦醒　刘永华

摘要 研究灰霉病菌接种后番茄叶片中蔗糖转化酶介导的糖分代谢的变化规律及其与发病程度之间的相关性，初步阐明蔗糖转化酶在调控番茄-灰霉病菌互作中的重要作用。通过系统测定灰霉病菌接种后不同时期（0、12、24和48 h）番茄叶片中蔗糖转化酶活性、淀粉和可溶性糖含量、细胞死亡程度和H2O2积累的动态变化，结果发现，灰霉病菌接种导致番茄叶片细胞壁转化酶（CWIN）、细胞质转化酶（CIN）和液泡转化酶（VIN）活性显著上升，其中CWIN活性最先上升且上升幅度最大，其次为CIN，最后为VIN;同时，CWIN和CIN活性在接种早期（12和24 h）上升幅度较小，而在接种后期（48 h）上升幅度较大;霉病菌接种导致番茄叶片中淀粉含量和己糖/蔗糖显著降低，但对蔗糖、葡萄和果糖含量没有显著影响;灰霉病菌接种导致番茄叶片在接种早期（24 h）发生显著的细胞死亡和H2O2积累现象。总之，灰霉病菌接种导致3种转化酶活性顯著上升，但由于其活性在接种早期上升幅度较小，其分解蔗糖产生的己糖（葡萄糖和果糖）不能满足植物防御反应的需要而出现己糖/蔗糖下降，这导致植物不能通过糖信号途径及时启动防御反应来有效清除H2O2并防止细胞死亡的发生，最终导致灰霉病的发生。

关键词 灰霉病;细胞壁转化酶;细胞质转化酶;液泡转化酶;己糖/蔗糖

中图分类号 S641.2文献标识码 A文章编号 0517-6611（2020）11-0156-05

Abstract To elucidate important roles of invertase in regulating tomatoB. cinerea interaction， the changes of invertasemediated sugar metabolism in tomato leaves after Botrytis cinerea inoculation and their correlation with the progress of grey mould incidence were studied. The dynamics of invertase activities， starch and soluble sugar content， cell death degree and H2O2 accumulation in tomato leaves at different timepoints （0， 12， 24 and 48 h） after B. cinerea inoculation were systematically investigated. It was found that cell wall invertase （CWIN）， cytoplasmic invertase （CIN） and vacuolar invertase （VIN） of tomato leaves were significantly increased after B. cinerea inoculation;among three kinds of INVs， CWIN activity was induced earliest and most dramatically， followed by CIN and VIN. Furthermore， induction of CWIN and CIN activity was moderate at the early stage of inoculation （12 and 24 h）， but was dramatic at the late stage of inoculation （48 h）. Starch content and hexose/sucrose in tomato leaves was significantly decreased after B. cinerea inoculation， but the content of sucrose， glucose and fructose was not significantly affected. In addition， B. cinerea inoculation resulted in significant cell death and H2O2 accumulation in tomato leaves at the early stage of inoculation （24 h）. Collectively， B. cinerea inoculation significantly induced the activities of three kinds of INVs. However， because the induction of INV activities was moderate at the early stage of inoculation， hexose derived from INVmediated sucrose degradation could not meet the need of plant defense response for hexose， which led to reduced hexose/sucrose. Thus， tomato plants fail to activate its defense response to effectively scavenge H2O2 and therefore prevent the incidence of H2O2induced cell death.

Key words Botrytis cinerea;Cell wall invertase;Cytoplasmic invertase;Vacuolar invertase;Hexose/sucrose

番茄（Solanum lycopersicm）是我国乃至世界上重要的蔬菜作物之一。据联合国粮农组织统计，2017年世界番茄总产量高达1.82亿t。……