Zhang Yi, Chen Haoting, Li Shuo, Li Yang, Kanwar Mukesh Kumar, Li Bin, Bai Longqiang, Xu Jin, Shi Yu
College of Horticulture, Shanxi Agricultural University, Jinzhong, China.
Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China.
Front Plant Sci. 2021 Nov 17;12:724288. doi: 10.3389/fpls.2021.724288. eCollection 2021.
Secondary salinization caused by the overaccumulation of calcium nitrate [Ca(NO)] in soils due to excessive fertilization has become one of the major handicaps of protected vegetable production. Brassinolide, a bioactive plant steroid hormone, plays an important role in improving abiotic stress tolerance in plants. However, whether and how brassinolide (BR) can alleviate Ca(NO) stress remains elusive. Here, we investigated the effects of exogenous BR on hydroponically grown tomato ( L.) plants under Ca(NO) stress through proteomics combined with physiological studies. Proteomics analysis revealed that Ca(NO) stress affected the accumulation of proteins involved in photosynthesis, stress responses, and antioxidant defense, however, exogenous BR increased the accumulation of proteins involved in chlorophyll metabolism and altered the osmotic stress responses in tomatoes under Ca(NO) stress. Further physiological studies supported the results of proteomics and showed that the exogenous BR-induced alleviation of Ca(NO) stress was associated with the improvement of photosynthetic efficiency, levels of soluble sugars and proteins, chlorophyll contents, and antioxidant enzyme activities, leading to the reduction in the levels of reactive oxygen species and membrane lipid peroxidation, and promotion of the recovery of photosynthetic performance, energy metabolism, and plant growth under Ca(NO) stress. These results show the importance of applying BR in protected agriculture as a means for the effective management of secondary salinization.
过度施肥导致土壤中硝酸钙[Ca(NO)]过度积累引起的次生盐渍化已成为设施蔬菜生产的主要障碍之一。油菜素内酯是一种具有生物活性的植物甾体激素，在提高植物对非生物胁迫的耐受性方面发挥着重要作用。然而，油菜素内酯（BR）是否以及如何缓解Ca(NO)胁迫仍不清楚。在此，我们通过蛋白质组学结合生理学研究，研究了外源BR对Ca(NO)胁迫下无土栽培番茄（L.）植株的影响。蛋白质组学分析表明，Ca(NO)胁迫影响了参与光合作用、胁迫反应和抗氧化防御的蛋白质积累，然而，外源BR增加了参与叶绿素代谢的蛋白质积累，并改变了Ca(NO)胁迫下番茄的渗透胁迫反应。进一步的生理学研究支持了蛋白质组学的结果，并表明外源BR诱导的Ca(NO)胁迫缓解与光合效率、可溶性糖和蛋白质水平、叶绿素含量以及抗氧化酶活性的提高有关，从而导致活性氧水平和膜脂过氧化水平降低，并促进Ca(NO)胁迫下光合性能、能量代谢和植物生长的恢复。这些结果表明，在设施农业中应用BR作为有效管理次生盐渍化的手段具有重要意义。
