Department of Fruit Tree Sciences, College of Horticulture, China Agricultural University, Beijing 100193, China.
College of Agronomy, Jiangxi Agricultural University, Nanchang, Jiangxi 330045, China.
Plant Cell Physiol. 2022 Jun 15;63(6):785-801. doi: 10.1093/pcp/pcac039.
Fruit flesh cell vacuoles play a pivotal role in fruit growth and quality formation. In the present study, intact vacuoles were carefully released and collected from protoplasts isolated from flesh cells at five sampling times along fig fruit development. Label-free quantification and vacuole proteomic analysis identified 1,251 proteins, 1,137 of which were recruited as differentially abundant proteins (DAPs) by fold change ≥ 1.5, P < 0.05. DAPs were assigned to 10 functional categories; among them, 238, 186, 109, 93 and 90 were annotated as metabolism, transport proteins, membrane fusion or vesicle trafficking, protein fate and stress response proteins, respectively. Decreased numbers of DAPs were uncovered along fruit development. The overall changing pattern of DAPs revealed two major proteome landscape conversions in fig flesh cell vacuoles: the first occurred when fruit developed from late-stage I to mid-stage II, and the second occurred when the fruit started ripening. Metabolic proteins related to glycosidase, lipid and extracellular proteins contributing to carbohydrate storage and vacuole expansion, and protein-degrading proteins determining vacuolar lytic function were revealed. Key tonoplast proteins contributing to vacuole expansion, cell growth and fruit quality formation were also identified. The revealed comprehensive changes in the vacuole proteome during flesh development were compared with our previously published vacuole proteome of grape berry. The information expands our knowledge of the vacuolar proteome and the protein basis of vacuole functional evolution during fruit development and quality formation.
果实果肉细胞液泡在果实生长和品质形成中起着关键作用。本研究中，通过从果肉细胞原生质体中小心释放和收集完整的液泡，在无花果果实发育的五个采样时间点进行了研究。无标记定量和液泡蛋白质组分析鉴定了 1251 种蛋白质，其中 1137 种被鉴定为差异丰度蛋白（DAP），其 fold change≥1.5，P<0.05。DAP 被分配到 10 个功能类别；其中，238、186、109、93 和 90 种分别注释为代谢、转运蛋白、膜融合或囊泡运输、蛋白质命运和应激响应蛋白。随着果实发育，DAP 的数量减少。DAP 的整体变化模式揭示了无花果果肉细胞液泡中两个主要的蛋白质组景观转换：第一个发生在果实从晚期 I 到中期 II 发育时，第二个发生在果实开始成熟时。揭示了与糖苷酶、脂质和细胞外蛋白相关的代谢蛋白，这些蛋白有助于碳水化合物储存和液泡扩张，以及决定液泡溶酶体功能的蛋白降解蛋白。还鉴定了有助于液泡扩张、细胞生长和果实品质形成的关键液泡膜蛋白。所揭示的果肉发育过程中液泡蛋白质组的综合变化与我们之前发表的葡萄浆果液泡蛋白质组进行了比较。这些信息扩展了我们对液泡蛋白质组和液泡功能进化的蛋白质基础的认识，这些进化在果实发育和品质形成过程中发生。
