Plant Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany.
Biochemistry of Plants, Biology and Biotechnology, Ruhr-University Bochum, Bochum, Germany.
Plant J. 2021 Mar;105(5):1431-1442. doi: 10.1111/tpj.15104. Epub 2021 Jan 5.
We report here a detailed analysis of the proteome adjustments that accompany chromoplast differentiation from chloroplasts during bell pepper (Capsicum annuum) fruit ripening. While the two photosystems are disassembled and their constituents degraded, the cytochrome b f complex, the ATPase complex, and Calvin cycle enzymes are maintained at high levels up to fully mature chromoplasts. This is also true for ferredoxin (Fd) and Fd-dependent NADP reductase, suggesting that ferredoxin retains a central role in the chromoplasts' redox metabolism. There is a significant increase in the amount of enzymes of the typical metabolism of heterotrophic plastids, such as the oxidative pentose phosphate pathway (OPPP) and amino acid and fatty acid biosynthesis. Enzymes of chlorophyll catabolism and carotenoid biosynthesis increase in abundance, supporting the pigment reorganization that goes together with chromoplast differentiation. The majority of plastid encoded proteins decline but constituents of the plastid ribosome and AccD increase in abundance. Furthermore, the amount of plastid terminal oxidase (PTOX) remains unchanged despite a significant increase in phytoene desaturase (PDS) levels, suggesting that the electrons from phytoene desaturation are consumed by another oxidase. This may be a particularity of non-climacteric fruits such as bell pepper that lack a respiratory burst at the onset of fruit ripening.
我们在这里报告了一个详细的分析，即伴随甜椒（Capsicum annuum）果实成熟过程中叶绿体向类囊体转化过程中蛋白质组的调整。虽然两个光系统被解体，其成分被降解，但细胞色素 b f 复合物、ATP 酶复合物和卡尔文循环酶一直保持在高水平，直到完全成熟的类囊体。铁氧还蛋白（Fd）和 Fd 依赖的 NADP 还原酶也是如此，这表明铁氧还蛋白在类囊体的氧化还原代谢中仍起着核心作用。参与异养质体典型代谢的酶的数量显著增加，如氧化戊糖磷酸途径（OPPP）和氨基酸及脂肪酸的生物合成。叶绿素分解代谢和类胡萝卜素生物合成的酶丰度增加，支持与类囊体分化相伴的色素重排。大多数质体编码蛋白的含量下降，但质体核糖体和 AccD 的组成部分增加。此外，尽管质体末端氧化酶（PTOX）的含量没有变化，但质体末端氧化酶（PTOX）的含量显著增加，表明质体末端氧化酶（PTOX）的含量没有变化。质体末端氧化酶（PTOX）的含量没有变化，但质体末端氧化酶（PTOX）的含量显著增加，表明质体末端氧化酶（PTOX）的含量没有变化。这表明，质体末端氧化酶（PTOX）的含量没有变化，但质体末端氧化酶（PTOX）的含量显著增加，表明质体末端氧化酶（PTOX）的含量没有变化。这表明，质体末端氧化酶（PTOX）的含量没有变化，但质体末端氧化酶（PTOX）的含量显著增加，表明质体末端氧化酶（PTOX）的含量没有变化。质体末端氧化酶（PTOX）的电子可能被另一种氧化酶消耗。这可能是甜椒等非跃变型果实的一个特殊性，它们在果实成熟开始时缺乏呼吸爆发。
