He Nan, Umer Muhammad Jawad, Yuan Pingli, Wang Weiwei, Zhu Hongju, Lu Xuqiang, Xing Yan, Gong Chengsheng, Batool Raufa, Sun Xiaowu, Liu Wenge
Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China.
Department of Horticulture, Hunan Agricultural University, Changsha, Hunan, China.
Front Plant Sci. 2023 Mar 9;14:1108795. doi: 10.3389/fpls.2023.1108795. eCollection 2023.
Flooding is a major stress factor impacting watermelon growth and production globally. Metabolites play a crucial role in coping with both biotic and abiotic stresses.
In this study, diploid (2X) and triploid (3X) watermelons were investigated to determine their flooding tolerance mechanisms by examining physiological, biochemical, and metabolic changes at different stages. Metabolite quantification was done using UPLC-ESI-MS/MS and a total of 682 metabolites were detected.
The results showed that 2X watermelon leaves had lower chlorophyll content and fresh weights compared to 3X. The activities of antioxidants, such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), were higher in 3X than in 2X. 3X watermelon leaves showed lower O production rates, MDA, and hydrogen peroxide (HO) levels in response to flooding, while higher ethylene production was observed. 3X had higher levels of dehydrogenase activity (DHA) and ascorbic acid + dehydrogenase (AsA + DHA), but both 2X and 3X showed a significant decline in the AsA/DHA ratio at later stages of flooding. Among them, 4-guanidinobutyric acid (mws0567), an organic acid, may be a candidate metabolite responsible for flooding tolerance in watermelon and had higher expression levels in 3X watermelon, suggesting that triploid watermelon is more tolerant to flooding.
This study provides insights into the response of 2X and 3X watermelon to flooding and the physiological, biochemical, and metabolic changes involved. It will serve as a foundation for future in-depth molecular and genetic studies on flooding response in watermelon.
洪水是影响全球西瓜生长和产量的主要胁迫因素。代谢物在应对生物和非生物胁迫中起着关键作用。
在本研究中，通过检测二倍体（2X）和三倍体（3X）西瓜在不同阶段的生理、生化和代谢变化，来研究它们的耐淹机制。使用超高效液相色谱-电喷雾串联质谱法（UPLC-ESI-MS/MS）进行代谢物定量分析，共检测到682种代谢物。
结果表明，与3X西瓜相比，2X西瓜叶片的叶绿素含量和鲜重较低。超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）等抗氧化剂的活性在3X西瓜中高于2X西瓜。3X西瓜叶片在遭受水淹时，O产生速率、丙二醛（MDA）和过氧化氢（HO）水平较低，而乙烯产量较高。3X西瓜的脱氢酶活性（DHA）和抗坏血酸+脱氢酶（AsA+DHA）水平较高，但在水淹后期，2X和3X西瓜的AsA/DHA比值均显著下降。其中，一种有机酸4-胍基丁酸（mws0567）可能是西瓜耐淹的候选代谢物，在3X西瓜中的表达水平较高，这表明三倍体西瓜更耐水淹。
本研究深入了解了2X和3X西瓜对水淹的响应以及所涉及的生理、生化和代谢变化。这将为未来深入开展西瓜水淹响应的分子和遗传研究奠定基础。
