Response mechanisms induced by exposure to high temperature in anthers from thermo-tolerant and thermo-sensitive tomato plants: A proteomic perspective

<div><p>Constant global warming is one of the most detrimental environmental factors for agriculture causing significant losses in productivity as heat stress (HS) conditions damage plant growth and reproduction. In flowering plants such as tomato, HS has drastic repercussions on development and functionality of male reproductive organs and pollen. Response mechanisms to HS in tomato anthers and pollen have been widely investigated by transcriptomics; on the contrary, exhaustive proteomic evidences are still lacking. In this context, a differential proteomic study was performed on tomato anthers collected from two genotypes (thermo-tolerant and thermo-sensitive) to explore stress response mechanisms and identify proteins possibly associated to thermo-tolerance. Results showed that HS mainly affected energy and amino acid metabolism and nitrogen assimilation and modulated the expression of proteins involved in assuring protein quality and ROS detoxification. Moreover, proteins potentially associated to thermo-tolerant features, such as glutamine synthetase, S-adenosylmethionine synthase and polyphenol oxidase, were identified.</p></div

Venn diagram summarizing proteomic results.

<p>The number of proteins showing significant changes in abundance in the four Image Analyses is reported. Proteins changing their abundance in both Image Analyses I and IV and in both Image Analyses II and III (one protein and two proteins, respectively) are not included in the diagram (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0201027#pone.0201027.t001" target="_blank">Table 1</a>).</p

Heat-map representation of the identified proteins.

<p>Fold change values in the four Image Analyses are reported according to a color-based representation.</p

Representative 2-DE gel of anther proteome.

<p>The proteomic map of M82 under CC is reported. Spots exhibiting significant differences in mean volume are indicated.</p

Proteins differentially represented in SAL and M82 anther proteomes.

<p>Functional classification and regulation of protein abundance are reported.</p

Additional file 2: Table S3. of Chloroplast proteome response to drought stress and recovery in tomato (Solanum lycopersicum L.)

Identification details for the proteins observed as differentially represented by 2D-DIGE. Reported are spot number, protein accession/description, MASCOT score, total and unique peptides detected, identification rank and unicity, experimental and theoretical peptide mass value, peptide charge state, peptide mass error, number of peptide missed cleavage(s), peptide score, peptide expectation value and sequence, including amino acid(s) modification. (XLSX 1109 kb

Additional file 1: Table S1. of Chloroplast proteome response to drought stress and recovery in tomato (Solanum lycopersicum L.)

Nucleotide sequence of primers used for qRT-PCR analyses. Figure S1. Representative 2D-DIGE showing the resolution of about 2600 protein spots from tomato chloroplasts in IEF using pH 3-10 NL 18 cm strips, followed by 12% T SDS-PAGE. Spot visualization was obtained with a Typhoon fluorescence scanner. Differentially represented spots further subjected to nLC-ESI-LIT-MS/MS analysis are highlighted. A Cy-2 labeled pooled sample mixture was used as an internal standard for quantitative measurements. Table S2. Listed are data referring to spot number, NCBI protein accession number, protein description, MASCOT score value, theoretical and experimental molecular mass and pI values, total and unique peptides detected, sequence coverage (%), EMPAI score value, fold change in drought stressed plants with respect to control, and fold change in recovered drought stressed plants with respect to well-watered control of the same age. In addition, data referring to protein spots not showing significant quantitative variations are reported in italics and are highlighted in green. Protein species showing either an incoherent quantitative trend or a constant trend among the experimental conditions are highlighted in blue. (PDF 2377 kb