State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling, Shaanxi, China.
Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada.
J Pineal Res. 2015 Aug;59(1):109-19. doi: 10.1111/jpi.12245. Epub 2015 Jun 5.
Melatonin has been reported to promote plant growth and development. Our experiments with Arabidopsis thaliana showed that exogenous applications of this molecule mediated invertase inhibitor (C/VIF)-regulated invertase activity and enhanced sucrose metabolism. Hexoses were accumulated in response to elevated activities by cell wall invertase (CWI) and vacuolar invertase (VI). Analyses of sugar metabolism-related genes revealed differential expression during plant development that was modulated by melatonin. In particular, C/VIF1 and C/VIF2 were strongly down-regulated by exogenous feeding. We also found the elevated CWI activity in melatonin-treated Arabidopsis improved the factors (cellulose, xylose, and galactose) for cell wall reinforcement and callose deposition during Pseudomonas syringae pv. tomato DC3000 infection, therefore, partially induced the pathogen resistance. However, CWI did not involve in salicylic acid (SA)-regulated defense pathway. Taken together, this study reveals that melatonin plays an important role in invertase-related carbohydrate metabolism, plant growth, and pathogen defense.
褪黑素已被报道能促进植物的生长和发育。我们对拟南芥的实验表明，这种分子的外源性应用介导了转化酶抑制剂（C/VIF）调节的转化酶活性，并增强了蔗糖代谢。己糖在细胞壁转化酶（CWI）和液泡转化酶（VI）活性升高的情况下积累。对糖代谢相关基因的分析表明，褪黑素对植物发育过程中的基因表达具有调节作用。特别是，C/VIF1 和 C/VIF2 在外源喂食时被强烈下调。我们还发现，褪黑素处理的拟南芥中 CWI 活性的升高，改善了细胞壁加固和丁香假单胞菌 pv.番茄 DC3000 感染过程中几丁质沉积的因素（纤维素、木糖和半乳糖），因此，部分诱导了对病原体的抗性。然而，CWI 不参与水杨酸（SA）调节的防御途径。总之，本研究揭示了褪黑素在与转化酶相关的碳水化合物代谢、植物生长和病原体防御中起着重要作用。
