Shen Wanqi, Zeng Chunfa, Zhang He, Zhu Kaijie, He Hao, Zhu Wei, He Hanzi, Li Guohuai, Liu Junwei
Key Laboratory of Horticultural Plant Biology, Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China.
Haikou Experimental Station, Chinese Academy of Tropical Agricultural Sciences, Haikou, China.
Front Plant Sci. 2021 Dec 15;12:794881. doi: 10.3389/fpls.2021.794881. eCollection 2021.
Autotoxicity is known as a critical factor in replanting problem that reduces land utilization and creates economic losses. Benzoic acid (BA) is identified as a major autotoxin in peach replant problem, and causes stunted seedling growth or even death. However, the physiological and molecular mechanisms of peach response to BA stress remain elusive. Here, we comprehensively studied the morphophysiological, transcriptional, and metabolic responses of peach plants to BA toxicity. Results showed that BA stress inhibited peach seedlings growth, decreased chlorophyll contents and fluorescence levels, as well as disturbed mineral metabolism. The contents of hydrogen peroxide, superoxide anion, and malondialdehyde, as well as the total antioxidant capacity, were significantly increased under BA stress. A total of 6,319 differentially expressed genes (DEGs) were identified after BA stress, of which the DEGs related to photosynthesis, redox, and ion metabolism were greatly changed; meanwhile, numerous stress-responsive genes (, , , and ) and transcription factors (, , , , and ) were noticeably altered under BA stress. BA induced metabolic reprogramming, and 74 differentially accumulated metabolites, including amino acids and derivatives, fatty acids, organic acids, sugars, and sugar alcohols, were identified in BA-stressed roots. Furthermore, an integrated analysis of genes and metabolites indicated that most of the co-mapped KEGG pathways were enriched in amino acid and carbohydrate metabolism, which implied a disturbed carbon and nitrogen metabolism after BA stress. The findings would be insightful in elucidating the mechanisms of plant response to autotoxicity stress, and help guide crops in alleviating replant problem.
自毒作用被认为是再植问题中的一个关键因素，它降低了土地利用率并造成经济损失。苯甲酸（BA）被确定为桃树再植问题中的一种主要自毒物质，会导致幼苗生长受阻甚至死亡。然而，桃树对BA胁迫的生理和分子机制仍不清楚。在此，我们全面研究了桃树对BA毒性的形态生理、转录和代谢反应。结果表明，BA胁迫抑制了桃树苗的生长，降低了叶绿素含量和荧光水平，还扰乱了矿物质代谢。在BA胁迫下，过氧化氢、超氧阴离子和丙二醛的含量以及总抗氧化能力显著增加。BA胁迫后共鉴定出6319个差异表达基因（DEGs），其中与光合作用、氧化还原和离子代谢相关的DEGs发生了很大变化；同时，许多胁迫响应基因（、、、和）和转录因子（、、、、和）在BA胁迫下也有明显改变。BA诱导了代谢重编程，在受BA胁迫的根系中鉴定出74种差异积累的代谢物，包括氨基酸及其衍生物、脂肪酸、有机酸、糖类和糖醇类。此外，对基因和代谢物的综合分析表明，大多数共映射的KEGG途径富集在氨基酸和碳水化合物代谢中，这意味着BA胁迫后碳和氮代谢受到干扰。这些发现将有助于阐明植物对自毒胁迫的响应机制，并有助于指导作物缓解再植问题。
