Role of Melatonin in Arbuscular Mycorrhizal Fungi-Induced Resistance to Fusarium Wilt in Cucumber
Role of Melatonin in Arbuscular Mycorrhizal Fungi-Induced Resistance to Fusarium Wilt in Cucumber
复制标题
褪黑素在丛枝菌根真菌诱导黄瓜枯萎病抗性中的作用
DOI：
10.1094/phyto-11-19-0435-r
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发表时间：
2020-05-01
期刊：
影响因子：
3.2
通讯作者：
Chen, Shuangchen
中科院分区：
文献类型：
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作者：
Ahammed, Golam Jalal;Mao, Qi;Chen, Shuangchen
褪黑激素是一种多功能的分子，赋予植物对许多生物和非生物胁迫的耐受性。然而，褪黑激素在植物对尖孢镰刀菌的反应中的作用以及与丛枝菌根真菌（AMF）的相互作用仍不清楚。在这里，我们表明，外源褪黑激素的应用促进AMF在黄瓜根中的定殖率，这可能抑制枯萎病的病情指数下降和控制效果增加证明。叶片气体交换分析表明，接种镰刀菌显著降低了叶片的净光合速率（Pn）、气孔导度（Gs）、胞间CO2浓度（Ci）和蒸腾速率（Tr）。有趣的是，无论是褪黑激素的应用或AMF接种显着增加Pn，Gs，Tr，和干生物量，和他们的组合处理下镰刀菌胁迫表现出更深刻的影响。进一步的分析表明，镰刀菌诱导的氧化应激表现为增加脂质过氧化和电解质渗漏。相反，无论是褪黑激素或AMF大大衰减的水平，丙二醛，过氧化氢，电解质渗漏镰刀菌接种的植物，和他们的组合治疗引起进一步减少。接种镰刀菌降低了超氧化物歧化酶和抗坏血酸过氧化物酶的活性和转录量，降低了谷胱甘肽和脯氨酸的含量。此外，过氧化物酶和过氧化氢酶的活性和转录量以及酚类和类黄酮的含量在镰刀菌侵染后也有所增加。重要的是，褪黑激素和/或AMF显着增加了这些参数，最大的效果与它们的组合处理下镰刀菌应力。我们的研究结果表明，褪黑激素和AMF之间的积极合作，提高黄瓜植株对枯萎病的抗性。
Melatonin is a multifunctional molecule that confers tolerance to a number of biotic and abiotic stresses in plants. However, the role of melatonin in plant response to Fusarium oxysporum and the interaction with arbuscular mycorrhizal fungi (AMF) remain unclear. Here we show that exogenous melatonin application promoted the AMF colonization rate in cucumber roots, which potentially suppressed Fusarium wilt as evidenced by a decreased disease index and an increased control effect. Leaf gas exchange analysis revealed that Fusarium inoculation significantly decreased the net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentrations (Ci), and transpiration rate (Tr). Intriguingly, either melatonin application or AMF inoculation significantly increased the Pn, Gs, Tr, and dry biomass, and their combined treatment showed a more profound effect under Fusarium stress. Further analysis showed that Fusarium induced oxidative stress as evidenced by increased lipid peroxidation and electrolyte leakage. Conversely, either melatonin or AMF drastically attenuated the levels of malondialdehyde, H2O2, and electrolyte leakage in Fusarium-inoculated plants, and their combined treatment caused a further decrease. Fusarium inoculation decreased the activity and transcripts of superoxide dismutase and ascorbate peroxidase, and the content of glutathione and proline. Besides, the activity and transcripts of peroxidase and catalase, the content of phenols and flavonoids increased after Fusarium infection. Importantly, melatonin and/or AMF significantly increased those parameters with the greatest effect with their combined treatment under Fusarium stress. Our results suggest that a positive collaboration between melatonin and AMF enhances resistance to Fusarium wilt in cucumber plants.