Melatonin mitigates cold-induced damage to pepper seedlings by promoting redox homeostasis and regulating antioxidant profiling

作     者：Muhammad Ahsan Altaf Yuanyuan Hao Huangying Shu Weiheng Jin Chuhao Chen Lin Li Yu Zhang Muhammad Ali Mumtaz Huizhen Fu Shanhan Cheng Guopeng Zhu Zhiwei Wang Muhammad Ahsan Altaf;Yuanyuan Hao;Huangying Shu;Weiheng Jin;Chuhao Chen;Lin Li;Yu Zhang;Muhammad Ali Mumtaz;Huizhen Fu;Shanhan Cheng;Guopeng Zhu;Zhiwei Wang

作者机构：Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan ProvinceSanya Nanfan Research InstituteHainan UniversitySanyaHainan 572025China Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan ProvinceSchool of HorticultureHainan UniversityHaikouHainan 570228China Hainan Yazhou Bay Seed LaboratorySanyaHainan 572025China 

出 版 物：《Horticultural Plant Journal》 (园艺学报（英文版）)

年 卷 期：2024年第10卷第2期

页      面：532-544页

核心收录：

学科分类：09[农学] 0902[农学-园艺学] 090202[农学-蔬菜学] 

基　　金：supported by the Major Science and Technology Plan of Hainan Province (Grant No.ZDKJ2021010),China National Key Research and Development Program,(Grant No.2018YFD1000800) China the National Natural Science Foundation (Grant No.31660091),China 

主　　题：Pepper Melatonin Cold stress Antioxidant enzyme Root trait 

摘      要：This study assessed the influence of exogenous ME in the mitigation of cold damage in pepper seedlings. Melatonin(ME) is a dynamic molecule that helps plants cope with stress in several ways. Cold stress(CS) is one of the most important environmental factors that restrict plant growth and yield. Pepper(Capsicum annuum L.) is a valuable commercial crop, highly sensitive to CS. Thus, identifying an efficient strategy to mitigate cold damage is critical for long-term pepper production. For this purpose, the roots of pepper seedlings were pretreated with ME(5 μmol · L^(-1)) and exposed to CS for 7 d. The results indicated that CS suppressed pepper growth, hampered photosynthetic capacity, and damaged root architecture in pepper plants. In contrast, the production of reactive oxygen species(ROS), malondialdehyde(MDA), electrolyte leakage(EL), proline, and soluble sugars were enhanced in plants under CS. ME(5 μmol · L^(-1)) pretreatment reduced the negative effects of CS by recovering plant growth, root traits, gas exchange elements, and pigment molecules compared to CS control treatment. Furthermore, ME application efficiently reduced oxidative stress markers [hydrogen peroxide(H_(2)O_(2)), superoxide ion(O_(2)^(·-)), EL, and MDA] while increasing proline and soluble sugar content in pepper leaves. ME application combined with CS further increased antioxidant enzymes and related gene expression. Collectively, our results confirmed the mitigating potential of ME supplementation for CS by maintaining pepper seedling growth,improving the photosynthesis apparatus, regulating pigments, and osmolyte content.