Effects of exogenous calcium on the drought response of the tea plant ( Camellia sinensis (L.) Kuntze)

作者：L. S. Malyukova, N. G. Koninskaya, Yuriy L. Orlov, Lidiia Samarina · 发表于：PeerJ · 年份：2022 · DOI：10.7717/peerj.13997 · 被引用次数：18 · 研究领域：Plant Stress Responses and Tolerance、Plant Parasitism and Resistance、Ginseng Biological Effects and Applications

Background Drought is one of the major factors reducing the yield of many crops worldwide, including the tea crop ( Camellia sinensis (L.) Kuntze). Calcium participates in most of cellular signaling processes, and its important role in stress detection and triggering a response has been shown in many crops. The aim of this study was to evaluate possible effects of calcium on the tea plant response to drought. Methods Experiments were conducted using 3-year-old potted tea plants of the best local cultivar Kolkhida. Application of ammonium nitrate (control treatment) or calcium nitrate (Ca treatment) to the soil was performed before drought induction. Next, a 7-day drought was induced in both groups of plants. The following physiological parameters were measured: relative electrical conductivity, pH of cell sap, and concentrations of cations, sugars, and amino acids. In addition, relative expression levels of 40 stress-related and crop quality–related genes were analyzed. Results Under drought stress, leaf electrolyte leakage differed significantly, indicating greater damage to cell membranes in control plants than in Ca-treated plants. Calcium application resulted in greater pH of cell sap; higher accumulation of tyrosine, methionine, and valine; and a greater Mg 2+ content as compared to control plants. Drought stress downregulated most of the quality-related genes in both groups of tea plants. By contrast, significant upregulation of some genes was observed, namely CRK45 , N...