Dataset Information

A proteomic analysis shows stimulation of light reactions and inhibition of Calvin cycle in skin chloroplasts of ripe red grape berries

ABSTRACT: The role of photosynthesis in fruits still challenges scientists. This is especially true in the case of mature grape berries of red varieties lined by an anthocyanin-enriched exocarp (skin) almost impermeable to gases. Although chlorophylls are degraded and replaced by carotenoids in several fruits, available evidence suggests that they may persist in red grapes at maturity. In the present study, chloroplasts were isolated from the skin of red grape berries (cv. Vinhão) to measure chlorophyll levels and the organelle proteome. The results showed that chloroplasts (and chlorophylls) are maintained in ripe berries masked by anthocyanin accumulation and that the proteome of chloroplasts from green and mature berries is distinct. Several proteins of the light reactions significantly accumulated in chloroplasts at the mature stage, including those of light-harvesting complexes of photosystems I (PSI) and II (PSII), redox chain, and ATP synthase, while chloroplasts at the green stage accumulated more proteins involved in the Calvin cycle and the biosynthesis of amino acids, including precursors of secondary metabolism. Taken together, results suggest that although chloroplasts are more involved in biosynthetic reactions in green berries, at the mature stage, they may provide ATP for energy-demanding processes such as anthocyanin biosynthesis or even O2 to feed the respiratory demand of inner tissues.

INSTRUMENT(S): LTQ Orbitrap

ORGANISM(S): Vitis Vinifera (grape)

TISSUE(S): Plant Cell, Skin

SUBMITTER: António Teixeira

LAB HEAD: António teixeira

PROVIDER: PXD037346 | Pride | 2022-10-25

REPOSITORIES: Pride

ACCESS DATA

Dataset's files

Source:

			Action	DRS
	2020MQ041_ANFO_001_01_2ug.raw	Raw
	2020MQ041_ANFO_001to008.msf	Msf
	2020MQ041_ANFO_002_01_2ug.raw	Raw
	2020MQ041_ANFO_003_01_2ug.raw	Raw
	2020MQ041_ANFO_004_01_2ug.raw	Raw

Items per page:

1 - 5 of 9

Similar Datasets

Project description:Anthocyanins are flavonoid compounds responsible for red/purple colours in the leaves, fruit and flowers of many plant species. They are produced through a multistep pathway which is controlled by MYB transcription factors. VvMYBA1 and VvMYBA2 activate anthocyanin biosynthesis in grapevine (Vitis vinifera) and are non-functional in white grapevine cultivars. In this study, transgenic grapevines with altered VvMYBA gene expression were developed, and transcript analysis was carried out on berries using a microarray technique. The results showed that VvMYBA is a positive regulator of the later stages of anthocyanin synthesis, modification and transport in Shiraz. One up-regulated gene ANTHOCYANIN 3- O-GLUCOSIDE-6â-O-ACYLTRANSFERASE (Vv3AT) encodes a BAHD acyltransferase protein, belonging to a clade separate from most anthocyanin acyltransferases. Functional studies (in planta and in vitro) show that Vv3AT has a broad anthocyanin substrate specificity and can also utilise both aliphatic and aromatic acyl donors, a novel activity for this enzyme family found in nature. In V. vinifera cv. Pinot Noir, a red-berried grapevine mutant lacking acylated anthocyanins, Vv3AT contains a nonsense mutation encoding a truncated protein that lacks two motifs required for BAHD protein activity. Promoter activation assays confirm that Vv3AT transcription is activated by VvMYBA1, which adds to the current understanding of the regulation of the BAHD gene family. The flexibility of Vv3AT to use both classes of acyl donors will be useful in the engineering of anthocyanins in planta or in vitro. Transgenic Chardonnay/Shiraz and non-transformed WT controls were all grown in the same glasshouse in ambient light with a night break. Day and night temperatures were approximately 27oC and 22oC respectively. For microarray experiments, whole berries were sampled from independent transgenic lines: three from transgenic Chardonnay and four from transgenic Shiraz, resulting in three and four biological replicates respectively. Bunches were harvested close to ripeness based on average total soluble solids (TSS, measured as oBrix). This was aimed to be between 20 â 24 oBrix and was determined from TTS of a subsamples from each bunch (Table S53). A sample consisted of all remaining berries from a single bunch except when there were <100 berries in which case more than one bunch was used in the one replicate. Whole berries were immediately frozen in liquid nitrogen. For skin samples, the skins were first removed from fresh berries then frozen in liquid nitrogen. All samples were stored at -80oC.

Project description:Plastids contain multiple copies of the plastid chromosome, folded together with proteins and RNA into nucleoids. The degree to which components of the plastid gene expression and protein biogenesis machineries are nucleoid associated, and the factors involved in plastid DNA organization, repair, and replication, are poorly understood. To provide a conceptual framework for nucleoid function, we characterized the proteomes of highly enriched nucleoid fractions of proplastids and mature chloroplasts isolated from the maize (Zea mays) leaf base and tip, respectively, using mass spectrometry. Quantitative comparisons with proteomes of unfractionated proplastids and chloroplasts facilitated the determination of nucleoid-enriched proteins. This nucleoid-enriched proteome included proteins involved in DNA replication, organization, and repair as well as transcription, mRNA processing, splicing, and editing. Many proteins of unknown function, including pentatricopeptide repeat (PPR), tetratricopeptide repeat (TPR), DnaJ, and mitochondrial transcription factor (mTERF) domain proteins, were identified. Strikingly, 70S ribosome and ribosome assembly factors were strongly overrepresented in nucleoid fractions, but protein chaperones were not. Our analysis strongly suggests that mRNA processing, splicing, and editing, as well as ribosome assembly, take place in association with the nucleoid, suggesting that these processes occur cotranscriptionally. The plastid developmental state did not dramatically change the nucleoid-enriched proteome but did quantitatively shift the predominating function from RNA metabolism in undeveloped plastids to translation and homeostasis in chloroplasts. This study extends the known maize plastid proteome by hundreds of proteins, including more than 40 PPR and mTERF domain proteins, and provides a resource for targeted studies on plastid gene expression. Details of protein identification and annotation are provided in the Plant Proteome Database.

Project description:Studying the effect of varying durations (1, 7 and 14 days) of locally applied heat stress on grape berries at three developmental stages (middle green, veraison and middle ripening). Among various environmental factors, temperature is a major regulator affecting plant growth, development and fruit composition. Reproductive development of grapevine and berry composition, are both highly influenced by temperature. To date, the molecular mechanisms involved in grapevine berries tolerance to high temperatures (HS) are poorly understood. Although recent data addressed the consequences on berry development of elevated temperatures applied at the whole plant level, the present work particularly focuses on the fruit responses triggered by direct exposure to heat stress. In the context of climate change, this work focused on microclimate effect is of particular interest to better understand the consequences of leaf removal (a common viticultural practice) on berry development. HS (+ 8°C) was locally applied to clusters from Cabernet Sauvignon fruiting cuttings at three different developmental stages (middle green, véraison and middle ripening). Samples were collected 1, 7 and 14 days after treatment and used for metabolic and transcriptomic analyses. The results showed dramatic and specific biochemical and transcriptomic changes in heat exposed berries, depending on the developmental stage and the stress duration. When applied at the herbaceous stage, HS delayed the onset of véraison. Heating also strongly altered the berry concentration of amino acids and organic acids (e.g. PHE, GABA, and malate) and decreased the anthocyanin content at maturity. These physiological alterations could be partly explained by the deep remodelling of transcriptome in heated berries. More than 7000 genes were deregulated in at least one of the nine experimental conditions. The most affected processes belong to the categories “stress responses”, “protein metabolism” and “secondary metabolisms”, highlighting the intrinsic capacity of grape berries to perceive heat stress and to build adaptive responses. Additionally, important changes in processes related to “transport”, “hormone” and “transcription” might contribute to the postponing of véraison. Finally, opposite effects depending on heating duration were observed for genes encoding enzymes of the general phenylpropanoid pathway, suggesting that the HS-induced decrease in anthocyanin content may result from a combination of transcript abundance and product degradation.

Dataset Information

A proteomic analysis shows stimulation of light reactions and inhibition of Calvin cycle in skin chloroplasts of ripe red grape berries

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets