Changes in the microsomal proteome of tomato fruit during ripening

Abstract

the variations in the membrane proteome of tomato fruit pericarp during ripening have been investigated by mass spectrometry-based label-free proteomics. Mature green (MG30) and red ripe (R45) stages were chosen because they are pivotal in the ripening process: MG30 corresponds to the end of cellular expansion, when fruit growth has stopped and fruit starts ripening, whereas R45 corresponds to the mature fruit. Protein patterns were markedly different: among the 1315 proteins identified with at least two unique peptides, 145 significantly varied in abundance in the process of fruit ripening. the subcellular and biochemical fractionation resulted in Go term enrichment for organelle proteins in our dataset, and allowed the detection of low-abundance proteins that were not detected in previous proteomic studies on tomato fruits. Functional annotation showed that the largest proportion of identified proteins were involved in cell wall metabolism, vesicle-mediated transport, hormone biosynthesis, secondary metabolism, lipid metabolism, protein synthesis and degradation, carbohydrate metabolic processes, signalling and response to stress. Tomato (Solanum lycopersicum L.) is a crop of high economic and nutritional value produced worldwide and the most widely used model to study different aspects of development and ripening of fleshy fruits 1. Fruit ripening coincides with seed maturation in the final phase of fruit development and is a highly coordinated, genetically programmed, irreversible phenomenon involving a series of physiological, biochemical, and organoleptic changes that lead to changes in colour, texture, flavour, aroma, and nutritional status 2. It is coordinated by drastic hormonal changes and, although ethylene is considered the major hormonal regulator in climacteric fruit ripening, other hormones such as auxin and abscisic acid (ABA) take part in this process 3. During fruit development, the concentration of carbohydrates, amino acids, and organic acids diminishes immediately after fruit setting and is partially recovered during fruit ripening 4 with increased sugar levels, starch hydrolysis, decreased acidity 1 , pulp softening 5 , aromatic component and color development 6. The tomato genome has been recently sequenced and annotated 7 and a number of post-genomic approaches have been used to gain insights into molecular networks controlling fruit development and ripening 8. High-throughput proteomics analyses were reported recently 9-13. Moreover, analyses of fruit transcriptomes 14,15 and metabolome 16,17 as well as multilevel studies integrating transcriptomics and metabolomics 4,18,19 , transcriptomics and enzyme profiles 20 , or transcriptomics, proteomics, and metabolomics 8,21 have been performed. These studies have provided an enormous amount of data that expands our knowledge of the molecular events associated with ripening. While many enzymes are soluble proteins, membrane-spanning or membrane-associated proteins are more challenging to proteomic analysis 22. In this work, we obtained a proteo...

A biochemical and proteomic approach to the analysis of tomato mutant fruit growth

“…Isoenzymes of S-adenosylmethionine-synthetase (spots 12 and 14) catalyse the biosynthesis of ethylene precursors, but this enzyme is also involved in the phenylpropanoid pathways related to components in the cell wall. Literature data report that more abundant isoenzymes of S-adenosylmethionine-synthetase were found in the MG30 stage, which is consistent with the dramatically increased ethylene production which occurs in the breaker stage (Pontiggia et al 2019). The down-regulation of these isoenzymes in our study could imply the delay of the beginning of the ripening process in the flacca mutant, but also had a negative effect on the synthesis of lignin and other secondary metabolites in the flacca fruits.…”

“…Proteomic profiling of the microsomal fraction of the tomato fruit in the mature green stage (MG30) corresponding to the end of cell expansion and the start of ripening showed an increased abundance of proteins involved in glycolysis and carbohydrate metabolism, amino acid biosynthesis and the catabolic process, the synthesis of precursor metabolites and energy, as well as proteins involved in cell wall synthesis and remodeling (Pontiggia et al 2019). Among the proteins involved in glycolysis several enzymes showed much higher abundance including enolase.…”

“…They are involved in fermentation and facilitate the interconversion between aldehydes and alcohols, but also have a role in the regulation of fruit maturation and aroma production during fruit ripening (Speirs et al 1998). The study of the microsomal proteome of tomato fruit pericarp showed that some forms of alcohol dehidrogenase are present only in mature green fruits, while others are present in the red ripe stage, which indicates their different role in fruit development (Pontiggia et al 2019). Overexpression of this enzyme at the red ripe stage in tomato fruit development is related to the accumulation of flavor volatiles in tomato fruits (Claudius & Ludivine 2017).…”

Identification, Classification, and Expression Analysis of the Triacylglycerol Lipase (TGL) Gene Family Related to Abiotic Stresses in Tomato

“…The different groups showed distinct expression patterns, for example, almost all genes in group A upregulated in the roots and the expression level of group C and E genes changed notably in parallel with fruit development, suggesting these two groups may be crucial for fruit development. Indeed, lipid composition is an important feature for fruit in the development stage [50,51], with lipophilic compounds in tomato fruits participating mainly in signaling, membrane structure, and development [52,53]. The diverse expression levels of SlTGL family genes in different organs or fruits at different stages, which was also confirmed by the in-house qRT-PCR analysis (Figure 7), indicates that these genes may have specific functions in the various developmental stages of tomato organs.…”

Effect of Transgenic Rootstock Grafting on the Omics Profiles in Tomato

“…From this fingerprinting of tomato fruits by UHPLC-ESI-MS, we found that GUS gene expression in rootstock had a limited effect on the production of proteins in tomato fruits. Recently, there were reports on proteomic analysis using Solanaceae plants for the study of the change of membrane proteins during ripening 83) . Our analysis using UHPLC-ESI-MS revealed that the contents of crude protein extracts were not different between the ST and SN fruits.…”