Genome-wide survey of glutaredoxin gene family in four Solanaceae species and exploitation of duplicated CC-type following different environmental stimuli in tomato (Solanum lycopersicum)

Glutaredoxins (GRXs) are ubiquitous oxidoreductases involved in cell signaling, development and plant defense response against oxidative stress. Despite this gene family has been characterized in several species, clues about their evolution, diversification and function in Solanaceae are still in infancy. By exploring genomes of cultivated tomato (Solanum lycopersicum), potato (S. tuberosum) and their wild relatives (S. pennellii, S. commersonii), a total of 237 GRX genes were identified and grouped in CPYC-, CGFS-, GRL- and CC-types. Focusing on cultivated tomato, we highlighted that a higher diversity within CC-type resulted from tandem duplication events, indicating that this latter might be the force driving GRXs evolution. The presence of a rich repertoire of cis-regulatory elements suggested specialized functions of SlGRXs in plant development, hormonal and (a)biotic stress responses, as also confirmed by their different expression patterns observed in various tissues and during fruit development through an in silico approach. qRT-PCR analysis revealed a divergent profile of tandem and segmental duplicated CC-type members in tomato response to abiotic stresses, pathogenic or beneficial microorganisms. This study reported the first insights on the GRX gene family in four Solanaceae species and provided a comprehensive and detailed analysis of their gene structure and role in tomato. The divergent profile of selected duplicated CC-type members against various environmental constraints, highlighted candidate genes that will be used as a reference for functional analysis and genetic improvement not only in tomato but also in related species.