Responses of physiological indexes and leaf epicuticular waxes of Brassica napus to Sclerotinia sclerotiorum infection
Responses of physiological indexes and leaf epicuticular waxes of Brassica napus to Sclerotinia sclerotiorum infection
复制标题
甘蓝型油菜生理指标及叶表皮蜡质对核盘菌侵染的响应
DOI：
10.1111/ppa.12060
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发表时间：
2014-02-01
期刊：
影响因子：
2.7
通讯作者：
Li, J. -N.
中科院分区：
文献类型：
--
作者：
Ni, Y.;Guo, Y. -J.;Li, J. -N.
利用两种对菌核病具有不同抗性的甘蓝型油菜，研究了表皮蜡是否参与甘蓝型油菜对菌核病的防御机制。除酯类外，敏感品种的蜡总含量和蜡成分均显著高于抗性品种。菌核菌侵染使两个品种的醛类含量增加，而抗性品种的烷烃和未知物含量增加。感病品种叶片正面的结晶棒多于抗性品种。对菌核病菌的抗性与蜡含量有关，而与总蜡量无关。抗病品种中蜡相关基因和致病相关基因（PR1）的转录上调也支持了这一观察结果。接种后，抗性品种的苯丙氨酸解氨酶（PAL）活性升高，感病品种的PAL活性降低，与它们的抗病性有关。烷烃、醇类、酮类和总蜡含量与PAL和多酚氧化酶活性呈负相关。除蜡后，抗性品种与未除蜡的幼苗相比，出现了更多的坏死斑，而易感品种无显著变化。结果表明，表皮蜡对抗性品种的防御作用大于感病品种。甘蓝型油菜的叶表皮蜡、防御酶和依赖水杨酸的信号通路都参与了对菌核病菌的防御。
Two Brassica napus genotypes with different resistances to Sclerotinia sclerotiorum were used to clarify whether or not the epicuticular wax is involved in the defence mechanism of B. napus to S. sclerotiorum. The total wax and wax constituents were significantly higher in the susceptible cultivar than in the resistant cultivar, except for esters. Infection by S. sclerotiorum increased the content of aldehydes in both cultivars, while increasing the content of alkanes and unknowns in the resistant cultivar. More crystalloid rods were observed on adaxial surfaces of leaves of the susceptible cultivar than on those of the resistant cultivar. The resistance to S. sclerotiorum was correlated to the responses of wax content but not the amount of total wax. The up-regulation of transcription of a wax-related gene and a pathogenesis-related gene (PR1) in the pathogen-challenged resistant cultivar also supported this observation. After inoculation, the increase in phenylalanine ammonia lyase (PAL) activity in the resistant cultivar and the decrease in the susceptible cultivar were correlated with their resistance to disease. The content of alkanes, alcohols, ketones and total wax were negatively correlated with the activities of PAL and polyphenoloxidase. After wax removal, the resistant cultivar developed more necrotic spots compared to seedlings with intact wax, whilst no significant change was observed for susceptible seedlings. These results show that epicuticular wax contributed more to the defence of resistant cultivars than susceptible cultivars. The leaf epicuticular wax, defence enzymes and salicylic acid-dependent signalling pathway all contribute to defence against S. sclerotiorum in B. napus.