Laboratory of Pomology, School of Agriculture, Aristotle University of Thessaloniki, 57001, Thermi, Greece.
Institute of Soil and Water Resources, ELGO-DEMETER, 57001, Thessaloniki, Greece.
Plant Mol Biol. 2020 Dec;104(6):597-614. doi: 10.1007/s11103-020-01063-2. Epub 2020 Sep 9.
This work provides the first system-wide datasets concerning metabolic changes in calcium-treated fruits, which reveal that exogenously applied calcium may specifically reprogram sweet cherry development and ripening physiognomy. Calcium modulates a wide range of plant developmental processes; however, the regulation of fruit ripening by calcium remains largely uncharacterized. In this study, transcriptome, proteome and metabolome profiling was used to document the responses of sweet cherry fruit to external calcium application (0.5% CaCl) at 15, 27 and 37 days after full blossom. Endogenous calcium loading in fruit across development following external calcium feeding was accompanied by a reduction in respiration rate. Calcium treatment strongly impaired water-induced fruit cracking tested by two different assays, and this effect depended on the fruit size, water temperature and light/dark conditions. Substantial changes in the levels of numerous polar/non-polar primary and secondary metabolites, including malic acid, glucose, cysteine, epicatechin and neochlorogenic acid were noticed in fruits exposed to calcium. At the onset of ripening, we identified various calcium-affected genes, including those involved in ubiquitin and cysteine signaling, that had not been associated previously with calcium function in fruit biology. Calcium specifically increased the abundance of a significant number of proteins that classified as oxidoreductases, transferases, hydrolases, lyases, and ligases. The overview of temporal changes in gene expression and corresponding protein abundance provided by interlinked analysis revealed that oxidative phosphorylation, hypersensitive response, DNA repair, stomata closure, biosynthesis of secondary metabolites, and proton-pump activity were mainly affected by calcium. This report provides the fullest characterization of expression patterns in calcium-responsive genes, proteins and metabolites currently available in fruit ripening and will serve as a blueprint for future biological endeavors.
本研究提供了首个关于钙处理果实代谢变化的系统数据集，揭示了外源钙可能特异性地重新编程甜樱桃的发育和成熟表型。钙调节广泛的植物发育过程；然而，钙对果实成熟的调控在很大程度上尚未被阐明。在这项研究中，使用转录组、蛋白质组和代谢组学分析来记录甜樱桃果实对外源钙处理（0.5% CaCl）在完全开花后 15、27 和 37 天的响应。外源钙处理后，果实内源性钙负荷增加伴随着呼吸速率的降低。钙处理强烈损害了通过两种不同测定方法测试的水诱导的果实开裂，并且这种效应取决于果实大小、水温以及光照/黑暗条件。在暴露于钙的果实中，注意到许多极性/非极性初级和次级代谢物的水平发生了实质性变化，包括苹果酸、葡萄糖、半胱氨酸、表儿茶素和新绿原酸。在成熟开始时，我们鉴定了各种受钙影响的基因，包括那些参与泛素和半胱氨酸信号转导的基因，这些基因以前与果实生物学中的钙功能无关。钙特异性地增加了大量被归类为氧化还原酶、转移酶、水解酶、裂合酶和连接酶的蛋白质的丰度。通过相互关联的分析提供的基因表达和相应蛋白质丰度的时间变化概述表明，氧化磷酸化、过敏反应、DNA 修复、气孔关闭、次生代谢物的生物合成以及质子泵活性主要受到钙的影响。本报告提供了目前在果实成熟中钙响应基因、蛋白质和代谢物表达模式的最全面描述，将为未来的生物学研究提供蓝图。
