Melatonin Relieves Ozone Stress in Grape Leaves by Inhibiting Ethylene Biosynthesis

Abstract

Ozone (O3) stress severely affects the normal growth of grape (Vitis vinifera L.) leaves. Melatonin (MT) plays a significant role in plant response to various abiotic stresses, but its role in O3 stress and related mechanisms are poorly understood. In order to understand the mechanism of MT in alleviate O3 stress in grape leaves, we perform a transcriptome analyses of grapes leaves under O3 stress with or without MT treatment. Transcriptome analysis showed that the processes of ethylene biosynthesis and signaling were clearly changed in “Cabernet Sauvignon” grapes under O3 and MT treatment. O3 stress induced the expression of genes related to ethylene biosynthesis and signal transduction, while MT treatment significantly inhibited the ethylene response mediated by O3 stress. Further experiments showed that both MT and aminoethoxyvinylglycine (AVG, an inhibitor of ethylene biosynthesis) enhanced the photosynthetic and antioxidant capacities of grape leaves under O3 stress, while ethephon inhibited those capacities. The combined treatment effect of MT and ethylene inhibitor was similar to that of MT alone. Exogenous MT reduced ethylene production in grape leaves under O3 stress, while ethephon and ethylene inhibitors had little effect on the MT content of grape leaves after O3 stress. However, overexpression of VvACO2 (1-aminocyclopropane-1-carboxylate oxidase2) in grape leaves endogenously induced ethylene accumulation and aggravated O3 stress. Overexpression of the MT synthesis gene VvASMT1 (acetylserotonin methyltransferase1) in tobacco (Nicotiana tabacum L.) alleviated O3 stress and reduced ethylene biosynthesis after O3 stress. In summary, MT can alleviate O3 stress in grape leaves by inhibiting ethylene biosynthesis.

Identification of Putative Markers of Non-infectious Bud Failure in Almond [Prunus dulcis (Mill.) D.A. Webb] Through Genome Wide DNA Methylation Profiling and Gene Expression Analysis in an Almond × Peach Hybrid Population

“…In rice, induction of the homologous gene, OsASMT1 , occurred following exposure to the cytokinin benzylaminopurine ( Bhowal et al, 2021 ) which is known to stimulate cell division. In tomato, melatonin enhances the expression of heat shock proteins following heat stress, improving thermotolerance ( Xu et al, 2016 ; Wang et al, 2018 ), while in grape, the role of ASMT1 was related to enhanced ozone tolerance in leaves ( Liu et al, 2021 ).…”

Phytohormones regulate the abiotic stress: An overview of physiological, biochemical, and molecular responses in horticultural crops

“…Furthermore, MEL treatment resulted in a considerable decrease in H 2 O 2 levels as well as increased antioxidant machinery (Wei et al, 2019). MEL application significantly improved growth status, photosynthesis, antioxidant activity of enzymes, and depletion of ROS generation in ozone-stressed grape leaves (Liu et al, 2021). Jahan et al (2020) observed that MEL application significantly increased micro and macro-nutrient absorption under nickel toxicity in tomato roots and leaves, whereas MEL treatment significantly lowered nickel deposition in both root and shoot system.…”

Melatonin-Induced Protection Against Plant Abiotic Stress: Mechanisms and Prospects

“…Mt crosstalk with various plant growth regulators helps stress alleviation; for example, grape leaves grown under O 3 were treated with MT modulated ethylene biosynthesis and signalling. O 3 induced a significant increase in genes expression linked with ethylene biosynthesis, while MT supplementation significantly inhibited the ethylene genes expression ( Liu et al, 2021 ). Further MT application also improved the photosynthetic performance and antioxidant activities under O 3 .…”

“…Further MT application also improved the photosynthetic performance and antioxidant activities under O 3 . The over-expression of MT synthesis gene VvASMT1 (acetylserotonin methyltransferase 1) also alleviated the O 3 stress and reduced the ethylene biosynthesis ( Liu et al, 2021 ). The effect of diverse MT concentrations (0, 0.1, 0.5, 2.5, and 12.5 μM) was studied on apple plants grown under O3 stress.…”