Chromoplast differentiation in bell pepper (Capsicum annuum) fruits

Abstract

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 6 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.

The kiwifruit amyloplast proteome (kfALP): a resource to better understand the mechanisms underlying amyloplast biogenesis and differentiation

“…Eight ATPases (e.g., Acc15442, Acc09749, Acc22473) increased significantly in protein abundance during the differentiation process. Similar changes in expression of ATPases have also been observed during chromoplast differentiation in tomato (Barsan et al., 2010), citrus (Zeng et al., 2015), and bell pepper (Rödiger et al., 2021), suggesting that mechanisms of ATP supply during chromoplast formation may be conserved across species, despite their differentiation from different types of plastids.…”

“…To test for conservation of plastid differentiation processes in different fruit, plastid proteomics data from tomato and bell pepper (characterized by chloroplast‐to‐chromoplast differentiation), and citrus (pre‐chromoplast to chromoplast) (Barsan et al., 2010; Rödiger et al., 2021; Zeng et al., 2015) were compared with data in the kfALP from ‘Hort16A’ (Figure 7a,c). The results are shown as a heatmap comparing functional classes in Figure S8a–e.…”

Physiological and Transcriptome Analyses Revealed the Mechanism by Which Deferoxamine Promotes Iron Absorption in Cinnamomum camphora

“…Many iron−containing compounds in plants are involved in photosynthesis. These include the cytochrome oxidase complex and ferredoxin [ 43 ]. When plants are deficient in iron, the photosynthetic rate decreases, which leads to the disintegration of thylakoids, which inhibits photosynthesis.…”

“Omics” insights into plastid behavior toward improved carotenoid accumulation

“…photosystem I, photosystem II, the cytochrome b6/f complex and the ATP synthase) ( Liu et al., 2020 ; He et al., 2022 ). Genes coding for catalytic subunit of Clp protease (clpP1), Acyl-CoA carboxylase catalytic subunit (accD) and two putative protein import components (Ycf1 and Ycf2) are consistently retained in most plastome ( Ma et al., 2017 ; Bouchnak and van Wijk, 2021 ; Rodiger et al., 2021 ). As a result of this conservation, plastid DNA markers are widely used to establish the phylogeny of many plant groups, such as Rosaceae , Solanaceae and Cucurbitaceae ( He et al., 2022 ; Miao et al., 2022 ; Zhang Z. et al., 2022 ).…”