Physiological basis of UV-C-induced resistance to Botrytis cinerea in tomato fruit -: I.: Role of pre- and post-challenge accumulation of the phytoalexin-rishitin
Physiological basis of UV-C-induced resistance to Botrytis cinerea in tomato fruit -: I.: Role of pre- and post-challenge accumulation of the phytoalexin-rishitin
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DOI：
10.1016/j.postharvbio.2007.05.013
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发表时间：
2008-01-01
影响因子：
7
通讯作者：
Arul, Joseph
中科院分区：
文献类型：
--
作者：
Charles, Marie Therese;Mercier, Julien;Arul, Joseph
以番茄果实为材料，研究了在高剂量UV-C（3.7kJ/m2）辐照下，贮藏期间番茄果实对灰霉病（Botrytis cinerea）抗性的诱导和维持。结果表明，处理后果实对病害的敏感性较强，但随后逐渐产生抗性，并一直保持到贮藏期35 d结束。高浓度紫外线预处理番茄诱导其合成和积累。这种积累是逐渐的，并在处理后15 d达到最大水平（46.23 mg/kg），然后在贮藏结束时下降到3.5 mg/kg。未处理的果实接种也诱导rishitin积累，但这种反应是在紫外线处理的水果高得多。在对照和紫外线处理的水果，积累的能力下降，成熟。紫外线处理后，果实中的Rishitin积累量与抗病性呈显著正相关。处理后立即增强的疾病易感性可能是由UV和接种诱导的短暂但严重的氧化应激的结果。随后在贮藏早期观察到的处理果实中的逐渐抗性可以归因于接种前后的Rishitin的积累。接种时存在的Rishitin水平似乎是抗性表达的主要因素，而接种后其积累似乎在抗性中起增强作用。然而，Rishitin水平不能解释所观察到的延长抗性的UV处理的番茄灰霉病，这表明，其他诱导防御也可能参与。(c)2007 Elsevier B. V.保留所有权利。
The induction and maintenance of resistance to gray mold rot (Botrytis cinerea) in tomato fruit during storage, exposed to hormic dose of UV-C (3.7 kJ/m(2)) was studied. Treated fruit were more susceptible to disease immediately after treatment, but thereafter, they became gradually resistant and the resistance was maintained until the end of the storage period of 35 d. Pre-storage treatment of tomato with the hormic UV dose-induced synthesis and accumulation of rishitin. This accumulation was gradual and reached a maximum level (46.23 mg/kg) by 15 d after treatment before the rishitin level declined to 3.5 mg/kg at the end of storage. Inoculation of untreated fruit also induced rishitin accumulation but this response was much higher in UV-treated fruit. In both control and UV-treated fruit, the capacity to accumulate rishitin declined with ripening. There was a significant correlation between rishitin accumulation in UV-treated fruit both before and after inoculation and disease resistance. The enhanced disease susceptibility immediately after treatment is likely the result of transient but severe oxidative stress-induced by both UV and inoculation. Subsequent gradual resistance observed in treated fruit during the early period of storage could be attributed to the accumulation of rishitin both before and after inoculation. The level of rishitin present at the time of inoculation appears to be the primary factor in the expression of resistance while its accumulation after inoculation appears to play a reinforcing role in resistance. However, rishitin level cannot account for the observed prolonged resistance of UV-treated tomato to gray mold rot, and it is suggested that other induced defenses might also be involved. (c) 2007 Elsevier B.V. All rights reserved.