Genome-Wide Identification of the AP2/ERF Gene Family and Functional Analysis of GmAP2/ERF144 for Drought Tolerance in Soybean

Abstract

Drought is a major environmental constraint that causes substantial reductions in plant growth and yield. Expression of stress-related genes is largely regulated by transcription factors (TFs), including in soybean [Glycine max (L.) Merr.]. In this study, 301 GmAP2/ERF genes that encode TFs were identified in the soybean genome. The TFs were divided into five categories according to their homology. Results of previous studies were then used to select the target gene GmAP2/ERF144 from among those up-regulated by drought and salt stress in the transcriptome. According to respective tissue expression analysis and subcellular determination, the gene was highly expressed in leaves and encoded a nuclear-localized protein. To validate the function of GmAP2/ERF144, the gene was overexpressed in soybean using Agrobacterium-mediated transformation. Compared with wild-type soybean, drought resistance of overexpression lines increased significantly. Under drought treatment, leaf relative water content was significantly higher in overexpressed lines than in the wild-type genotype, whereas malondialdehyde content and electrical conductivity were significantly lower than those in the wild type. Thus, drought resistance of transgenic soybean increased with overexpression of GmAP2/ERF144. To understand overall function of the gene, network analysis was used to predict the genes that interacted with GmAP2/ERF144. Reverse-transcription quantitative PCR showed that expression of those interacting genes in two transgenic lines was 3 to 30 times higher than that in the wild type. Therefore, GmAP2/ERF144 likely interacted with those genes; however, that conclusion needs to be verified in further specific experiments.

ERF subfamily transcription factors and their function in plant responses to abiotic stresses

“…Salinity is a widespread abiotic stress that constrains plant growth ( Wang D. et al., 2021 ). Under salt stress, plants suffer osmotic stress and ionic toxicity ( Wang H. et al., 2022 ). Osmotic and ionic stresses further exert detrimental effects on plants, such as oxidative stress ( Yang and Guo, 2018 ).…”

Insights into the regulation of wild soybean tolerance to salt-alkaline stress

“…The AP2/ERF family in plants could be divided into five major subfamilies, AP2, ERF, RAV (Related to Abscisic acid insensitive 3/Viviparous 1), DREB (Dehydration-Responsive Element Binding), and Soloist ( Xie et al., 2019 ). According to a recent study, the soybean genome contains 301 AP2/ERF genes, among which 153 were classified into the ERF subfamily ( Wang H. et al., 2022a ). In G. soja , only three ERF subfamily TFs ( GsERF7 , GsERF71 and, GsERF6 ) have been suggested to participate in salt-alkaline stress response ( Figure 4A ).…”

Genome-Wide Characterization and Expression Analysis of Transcription Factor Families in Desert Moss Syntrichia caninervis under Abiotic Stresses

“…Based on the tree topology and sequence similarities, the AP2/ERF TF family was assigned to the AP2, DREB, ERF, RAV, and soloist subfamilies ( Figure 4 A). To classify these S. caninervis subfamilies, previous annotations of the plant AP2/ERF subfamilies have been considered [ 34 , 35 ]. The DREB subfamily had the most AP2/ERF members ( S. caninervis (41), A. thaliana (48), and P. patens (75) genes) followed by The ERF subfamily ( S. caninervis (26), A. thaliana (84) and P. patens (38) genes), and AP2 subfamily ( S. caninervis (7), A. thaliana (28) and P. patens (14) genes).…”

“…S. caninervis gametophytes were harvested from the Gurbantunggut Desert of Xinjiang Uygur Autonomous Region of China [ 31 , 32 , 33 , 34 , 35 ]. The S. caninervis sample was placed in Petri dishes and stored in an air-dried place at room temperature for at least one week, and then the gametophytes were fully rehydrated for 24 h before stress treatment.…”