Differential expression analysis of a subset of GmNAC genes in shoots of two contrasting drought-responsive soybean cultivars DT51 and MTD720 under normal and drought conditions

Abstract

NAC transcription factors are known to be involved in regulation of plant responses to drought stress. In this study, the expression of 23 drought-responsive GmNAC genes was assessed in the shoot tissues of DT51 and MTD720, the two soybean varieties with contrasting drought-responsive phenotypes, by real-time quantitative PCR (RT-qPCR) under normal and drought conditions. Results indicated that expression profile of GmNAC genes was genotype-dependent, and six GmNACs (GmNAC019, 043, 062, 085, 095 and 101) had higher transcript levels in the shoots of the drought-tolerant DT51 in comparison with the drought-sensitive MTD720 under drought. Our study suggests a positive correlation between the higher drought tolerance degree of DT51 versus MTD720 and the up-regulation of at least these six drought-responsive GmNACs in the shoot tissues. Furthermore, on the basis of our analysis, three genes, GmNAC043, 085 and 101, were identified as promising candidates for development of drought-tolerant soybean cultivars by genetic engineering.

Correlation between differential drought tolerability of two contrasting drought-responsive chickpea cultivars and differential expression of a subset of CaNAC genes under normal and dehydration conditions

“…The more CaNAC genes are up-regulated and the less CaNAC genes down-regulated by dehydration, the higher drought-tolerant the cultivar is. In support of our results, previous studies in soybean ( Glycine max ) also identified positive correlation between the number of drought-inducible GmNAC genes and drought-tolerant capacity of 2 contrasting cultivars (Thao et al, 2013; Thu et al, 2014a). …”

“…This finding suggested that the expression of CaNAC genes, at least of those examined in this study, is tissue- and genotype-dependent, which might then result in different phenotypes of different cultivars. Differential expression analyses of GmNAC genes in 3 soybean cultivars with different phenotypes also showed their tissue- and genotype-dependent expression patterns (Le et al, 2011b; Thao et al, 2013; Thu et al, 2014a,c), further supporting our observation.…”

“…One of the best studies that reported the potential application of NAC genes in agriculture is the work of Hu et al (2006), who reported that transgenic rice plants overexpressing SNAC1 exhibited enhanced drought tolerance without yield penalty. Since then, an increasing number of studies, including transgenic or correlation analyses, have provided strong evidence for the correlation between NAC gene expression and drought-tolerant capacity of various crops (Nakashima et al, 2007; Zheng et al, 2009; Xue et al, 2011; Thao et al, 2013; Thu et al, 2014a; Zhu et al, 2014; Yang et al, 2015). …”

“…Among the TF families, the plant-specific NAC [no apical meristem (NAM), Arabidopsis transcription activation factor (ATAF), and cup-shaped cotyledon (CUC)] TF family members have been intensively studied owing to their functions in a wide range of biological processes in plants, including regulation of plant responses to environmental stimuli (Olsen et al, 2005; Tran et al, 2010; Nakashima et al, 2012; Puranik et al, 2012). Increasing number of reports have shown convincing evidence correlating drought tolerance of various plant species and expression of NAC genes (Tran et al, 2004; Hu et al, 2006; Nakashima et al, 2007; Thao et al, 2013; Thu et al, 2014a), suggesting their potential for genetic engineering of improved drought-tolerant crop varieties.…”

Comprehensive analysis and discovery of drought-related NAC transcription factors in common bean

“…Tran et al analyzed 31 full-length NAC genes from soybean and determined that nine were induced by drought [46]. GmNAC043, GmNAC085 and GmNAC101 were identified in drought-tolerant soybean cultivars by genetic engineering [47]. However, there have been no reports about drought-tolerant related NAC TFs from common bean.…”