Effects of Light and Daytime on the Regulation of Chitosan-Induced Stomatal Responses and Defence in Tomato Plants
Effects of Light and Daytime on the Regulation of Chitosan-Induced Stomatal Responses and Defence in Tomato Plants
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DOI：
10.3390/plants9010059
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发表时间：
2020-01-01
期刊：
影响因子：
4.5
通讯作者：
Ordog, Attila
中科院分区：
文献类型：
--
作者：
Czekus, Zalan;Poor, Peter;Ordog, Attila
植物发病后气孔关闭是植物最早的免疫反应之一。然而，我们的知识是非常有限的依赖性植物防御反应壳聚糖（CHT）的外部因素（例如，一天中的时间，光的存在或不存在）。CHT在17：00小时处理的叶片中诱导气孔在暗/光转换之前关闭，并且在黎明和早晨处理的植物中气孔在09：00小时关闭。CHT能够在光相的第一部分诱导保卫细胞中活性氧（ROS）的产生，但仅在15：00小时观察到显著的一氧化氮产生。保卫细胞PSII电子传递的实际量子产率（Phi（PSII））在09：00时处理后下降，而叶肉细胞在17：00时处理后仅在黎明时下降。病程相关1（PR 1）和乙烯反应因子1的表达已经增加在黎明时在CHT处理的叶片，但PR 1的表达在黑暗中受到抑制。CHT诱导的系统反应也观察到在CHT处理的远侧叶。我们的研究结果表明，延迟和白天依赖的番茄植株CHT处理后，在夜间和黑暗中的防御反应。
Closure of stomata upon pathogenesis is among the earliest plant immune responses. However, our knowledge is very limited about the dependency of plant defence responses to chitosan (CHT) on external factors (e.g., time of the day, presence, or absence of light) in intact plants. CHT induced stomatal closure before dark/light transition in leaves treated at 17:00 hrs and stomata were closed at 09:00 hrs in plants treated at dawn and in the morning. CHT was able to induce generation of reactive oxygen species (ROS) in guard cells in the first part of the light phase, but significant nitric oxide production was observable only at 15:00 hrs. The actual quantum yield of PSII electron transport (Phi(PSII)) decreased upon CHT treatments at 09:00 hrs in guard cells but it declined only at dawn in mesophyll cells after the treatment at 17:00 hrs. Expression of Pathogenesis-related 1 (PR1) and Ethylene Response Factor 1 were already increased at dawn in the CHT-treated leaves but PR1 expression was inhibited in the dark. CHT-induced systemic response was also observed in the distal leaves of CHT-treated ones. Our results suggest a delayed and daytime-dependent defence response of tomato plants after CHT treatment at night and under darkness.