A Genome-Wide Analysis of StTGA Genes Reveals the Critical Role in Enhanced Bacterial Wilt Tolerance in Potato During Ralstonia solanacearum Infection

Abstract

TGA is one of the members of TGACG sequence-specific binding protein family, which plays a crucial role in the regulated course of hormone synthesis as a stress-responsive transcription factor (TF). Little is known, however, about its implication in response to bacterial wilt disease in potato (Solanum tuberosum) caused by Ralstonia solanacearum. Here, we performed an in silico identification and analysis of the members of the TGA family based on the whole genome data of potato. In total, 42 StTGAs were predicted to be distributed on four chromosomes in potato genome. Phylogenetic analysis showed that the proteins of StTGAs could be divided into six sub-families. We found that many of these genes have more than one exon according to the conserved motif and gene structure analysis. The heat map inferred that StTGAs are generally expressed in different tissues which are at different stages of development. Genomic collinear analysis showed that there are homologous relationships among potato, tomato, pepper, Arabidopsis, and tobacco TGA genes. Cis-element in silico analysis predicted that there may be many cis-acting elements related to abiotic and biotic stress upstream of StTGA promoter including plant hormone response elements. A representative member StTGA39 was selected to investigate the potential function of the StTGA genes for further analysis. Quantitative real-time polymerase chain reaction (qRT-PCR) assays indicated that the expression of the StTGAs was significantly induced by R. solanacearum infection and upregulated by exogenous salicylic acid (SA), abscisic acid (ABA), gibberellin 3 (GA3), and methyl jasmonate (MeJA). The results of yeast one-hybrid (Y1H) assay showed that StTGA39 regulates S. tuberosum BRI1-associated receptor kinase 1 (StBAK1) expression. Thus, our study provides a theoretical basis for further research of the molecular mechanism of the StTGA gene of potato tolerance to bacterial wilt.

Comparatively Evolution and Expression Analysis of GRF Transcription Factor Genes in Seven Plant Species

“…Previous reports also indicated that interactions between SVP and FLM isoforms modulated the temperature-responsive induction of flowering in Arabidopsis [51]. StTGAs were generally expressed in different tissues at different stages of development [52]. At WRKY70 was involved in drought response [53], and IbNAC3 modulates combined salt and drought stresses [54], while the expression level of TaWRKY70 was increased significantly when exposed to high temperature.…”

Genome-Wide Identification and Expression Analysis of TGA Family Genes Associated with Abiotic Stress in Sunflowers (Helianthus annuus L.)

“…Additionally, in Solanum lycopersicum, brassinoidsteroid (BR) induces the expression of TGA2, which in turn triggers the removal of pesticide residues in tomatoes by inducing apoplastic ROS [13]. The TGA factors have been associated with enhanced resistance to biotic stressors in various plant species; for instance, the StTGA gene has been linked to the improved ability to withstand bacterial wilt in Solanum tuberosum (potato) [14]. GmTGAs have been reported to improve symbiotic nodulation and nitrogen use efficiency in Glycine max (soybean) [15].…”

“…In addition to functional roles in stress response pathways, TGA1 and TGA4 have been recognized as important regulatory factors of the nitrate response in Arabidopsis roots, exemplifying the versatility of these factors in nutrient signaling and utilization [17]. Currently, the TGA gene family has been identified and functionally analyzed in soybeans [1], peanuts [18], and potatoes [14], where 27, 20, and 42 TGA genes have been identified, respectively. The ongoing elucidation of TGA gene functions continues to reveal new aspects of their contribution to plant resilience and offers promising targets for crop improvement strategies.…”

Genome-wide identification of TGA transcription factors in wheat: Evolution, expression and verification

“…In recent years, comprehensive analyses of the TGA transcription factor have been reported in soybean [18], potato [19], tomato [20,21], and peach [22]. The TGA enhances the plant's resistance to the pathogen in tomato and peach.…”