Identification of early salt stress responsive proteins in seedling roots of upland cotton (Gossypium hirsutum L.) employing iTRAQ-based proteomic technique

Abstract

Soil salinity is a major abiotic stress that limits plant growth and agricultural productivity. Upland cotton (Gossypium hirsutum L.) is highly tolerant to salinity; however, large-scale proteomic data of cotton in response to salt stress are still scant. Here, an isobaric tag for relative and absolute quantitation (iTRAQ)-based proteomic technique was employed to identify the early differentially expressed proteins (DEPs) from salt-treated cotton roots. One hundred and twenty-eight DEPs were identified, 76 of which displayed increased abundance and 52 decreased under salt stress conditions. The majority of the proteins have functions related to carbohydrate and energy metabolism, transcription, protein metabolism, cell wall and cytoskeleton metabolism, membrane and transport, signal transduction, in addition to stress and defense. It is worth emphasizing that some novel salt-responsive proteins were identified, which are involved in cell cytoskeleton metabolism (actin-related protein2, ARP2, and fasciclin-like arabinogalactan proteins, FLAs), membrane transport (tonoplast intrinsic proteins, TIPs, and plasma membrane intrinsic proteins, PIPs), signal transduction (leucine-rich repeat receptor-like kinase encoding genes, LRR-RLKs) and stress responses (thaumatin-like protein, TLP, universal stress protein, USP, dirigent-like protein, DIR, desiccation-related protein PCC13-62). High positive correlation between the abundance of some altered proteins (superoxide dismutase, SOD, peroxidase, POD, glutathione S-transferase, GST, monodehydroascorbate reductase, MDAR, and malate dehydrogenase, MDH) and their enzyme activity was evaluated. The results demonstrate that the iTRAQ-based proteomic technique is reliable for identifying and quantifying a large number of cotton root proteins. qRT-PCR was used to study the gene expression levels of the five above-mentioned proteins; four patterns are consistent with those of induced protein. These results showed that the proteome of cotton roots under NaCl stress is complex. The comparative protein profiles of roots under salinity vs control improves the understanding of the molecular mechanisms involved in the tolerance of plants to salt stress. This work provides a good basis for further functional elucidation of these DEPs using genetic and/or other approaches, and, consequently, candidate genes for genetic engineering to improve crop salt tolerance.

Genome-Wide Identification, Characterization and Expression Profiling of ADF Family Genes in Solanum lycopersicum L.

“…Accordingly, cytoskeleton rearrangement is used as a marker for various stress signaling pathways such as salt, cold, gravity, osmotic pressure, wounding and pathogen attack [49,50,51,52]. Together, ADF, actin-related protein 2 (ARP2) and actin-binding protein 29 (ABP29) are involved in actin cytoskeleton remodeling under salt stress conditions [53]. The rapid reorganization of the cytoskeleton structure promotes salinity tolerance in cotton roots [54].…”

Comparative Genome-Wide Analysis of the Malate Dehydrogenase Gene Families in Cotton

“…Likewise, the transcription level of PgMDH under chilling stress was maximum at 1 hour post-treatment and then decreased very little, while, during salinity stress (100 mM NaCl) the PgMDH was highly expressed and continues to increase from 1 day to 3 day treatment, indicated that this gene was related with response to stress and expression was increased after treatments of chilling and salt [78]. On the other hand, iTRAQ based proteomic analysis of cotton roots under salt stress concluded that there is a weak correlation between the transcript level of MDH gene and corresponding protein abundance, which highlights the effect of post-transcriptional modifications [79]. However, MDH genes, which are up-regulated during several abiotic stresses, are likely to be required to enhance resistance to stress, for example, the overexpression of MdcyMDH conferred high tolerance to cold and salt stresses in apple callus and transgenic tomatoes [8].…”

Functional and Integrative Analysis of the Proteomic Profile of Radish Root under Pb Exposure

“…Isobaric tags for relative and absolute quantification (iTRAQ) is a robust mass spectrometry of protein quantitative technology, which can perform relative and absolute quantification in up to eight samples in parallel (Bindschedler and Cramer, 2011; Glibert et al, 2014). Recently, iTRAQ has been widely used for large-scale quantitative plant proteomic studies in exploration of various metabolic processes at the post-transcriptional level (Kambiranda et al, 2013; Martínez-Esteso et al, 2013) in response to various stresses (Yang et al, 2014; Li et al, 2015; Fu et al, 2016). Additionally, iTRAQ-based proteomics has been proven as a powerful method for unraveling the molecular regulatory networks involved in interactions between heavy metals and plant species, and a set of HM-responsive candidate proteins have been successfully identified.…”