Genome-wide identification and expression analysis of glutathione S-transferase gene family in tomato: Gaining an insight to their physiological and stress-specific roles

Abstract

Glutathione S-transferase (GST) refers to one of the major detoxifying enzymes that plays an important role in different abiotic and biotic stress modulation pathways of plant. The present study aimed to a comprehensive genome-wide functional characterization of GST genes and proteins in tomato (Solanum lycopersicum L.). The whole genome sequence analysis revealed the presence of 90 GST genes in tomato, the largest GST gene family reported till date. Eight segmental duplicated gene pairs might contribute significantly to the expansion of SlGST gene family. Based on phylogenetic analysis of tomato, rice, and Arabidopsis GST proteins, GST family members could be further divided into ten classes. Members of each orthologous class showed high conservancy among themselves. Tau and lambda are the major classes of tomato; while tau and phi are the major classes for rice and Arabidopsis. Chromosomal localization revealed highly uneven distribution of SlGST genes in 13 different chromosomes, where chromosome 9 possessed the highest number of genes. Based on publicly available microarray data, expression analysis of 30 available SlGST genes exhibited a differential pattern in all the analyzed tissues and developmental stages. Moreover, most of the members showed highly induced expression in response to multiple biotic and abiotic stress inducers that could be harmonized with the increase in total GST enzyme activity under several stress conditions. Activity of tomato GST could be enhanced further by using some positive modulators (safeners) that have been predicted through molecular docking of SlGSTU5 and ligands. Moreover, tomato GST proteins are predicted to interact with a lot of other glutathione synthesizing and utilizing enzymes such as glutathione peroxidase, glutathione reductase, glutathione synthetase and γ-glutamyltransferase. This comprehensive genome-wide analysis and expression profiling would provide a rational platform and possibility to explore the versatile role of GST genes in crop engineering.

Genome-Wide Identification, Characterization, and Expression Profiling of Glutathione S-Transferase (GST) Family in Pumpkin Reveals Likely Role in Cold-Stress Tolerance

“…In contrast, CmaGSTU6 and CmaGSTU9 were not expressed in the stem and CmaGSTZ03 was not expressed in the flower buds, suggesting that they might not be responsible for the development of these respective organs ( Figure 6 ). The rest of the GST genes were expressed in all tested organs, consistent with the organ-specific microarray expression data of the AtGSTs [ 12 ], tomato ( Solanum lycopersicum ) GSTs [ 63 ], and OsGSTs [ 67 ].…”

“…The GST genes play key roles in plant growth and stress responses [ 59 , 63 , 64 , 65 ]. Plants have a high number of GSTs categorized into 14 classes [ 11 ], which can have constitutive or tissue-specific expression, or be induced by biotic and abiotic stresses.…”

Exploring natural diversity of Medicago truncatula reveals physiotypes and loci associated with the response of seedling performance to nitrate supply

“…5C). Cluster spots of GST genes due to gene duplication events are generally found in plants genomes (Dixon et al 2002, Sappl et al 2009, Islam et al 2017, Abdul Kayum et al 2018, Han et al 2018). GST genes have been classified into different classes based on their genomic localization and their function (Dixon et al 2010).…”

PpGST1, an anthocyanin‐related glutathione S‐transferase gene, is essential for fruit coloration in peach

“…In plants, GSTs are encoded by a large gene family and ubiquitously participate in signalling, flavonoid metabolism and response to biotic and abiotic stresses (Loyall et al, 2000;Moons, 2005). So far, numerous GSTs have been identified in plants, including 53 in Arabidopsis thaliana (Sappl et al, 2009), 20 in Dracaena cambodiana (Zhu et al, 2016), 139 in Litchi chinensis (Hu et al, 2016), 61 in Citrus sinensis (Licciardello et al, 2014) and 90 in Solanum lycopersicum (Islam et al, 2017). Among various functions, GSTs are also known to mediate trafficking and accumulation of anthocyanins.…”