Overexpression of a Miscanthus lutarioriparius NAC gene MlNAC5 confers enhanced drought and cold tolerance in Arabidopsis

Abstract

MLNAC5 functions as a stress-responsive NAC transcription factor gene and enhances drought and cold stress tolerance in transgenic Arabidopsis via the ABA-dependent signaling pathway. NAC transcription factors (TFs) play crucial roles in plant responses to abiotic stress. Miscanthus lutarioriparius is one of Miscanthus species native to East Asia. It has attracted much attention as a bioenergy crop because of its superior biomass productivity as well as wide adaptability to different environments. However, the functions of stress-related NAC TFs remain to be elucidated in M. lutarioriparius. In this study, a detailed functional characterization of MlNAC5 was carried out. MlNAC5 was a member of ATAF subfamily and it showed the highest sequence identity to ATAF1. Subcellular localization of MlNAC5-YFP fusion protein in tobacco leaves indicated that MlNAC5 is a nuclear protein. Transactivation assay in yeast cells demonstrated that MlNAC5 functions as a transcription activator and its activation domain is located in the C-terminus. Overexpression of MlNAC5 in Arabidopsis had impacts on plant development including dwarfism, leaf senescence, leaf morphology, and late flowering under normal growth conditions. Furthermore, MlNAC5 overexpression lines in Arabidopsis exhibited hypersensitivity to abscisic acid (ABA) and NaCl. Moreover, overexpression of MlNAC5 in Arabidopsis significantly enhanced drought and cold tolerance by transcriptionally regulating some stress-responsive marker genes. Collectively, our results indicated that MlNAC5 functions as an important regulator during the process of plant development and responses to salinity, drought and cold stresses.

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

“…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). …”

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

“…In plants, NAC genes regulate a variety of plant developmental processes, including floral morphogenesis [24], root development [25], leaf senescence [26, 27], stress-inducible flowering induction [28], seed development [29] and fiber development [30]. NAC domain proteins have also been implicated in plant abiotic stresses and defense responses, such as salt [31, 32], wounding [33], cold [34], and particularly drought [31, 32, 35]. For example, ANAC019, ANAC055, ANAC072 and ATAF1 regulate the expression of stress-responsive genes under drought stress in Arabidopsis [36, 37].…”

Cloning, Characterization, and Expression Analysis of Eight Stress‐Related NAC Genes in Tartary Buckwheat

“…For example, ATAF1 is strongly responsive to ABA and dehydration. (Puranik et al, 2013), and Miscanthus lutarioriparius Liu ex Chen & Renvoize ( Ji et al, 2014;Yang et al, 2015). RD26/ANAC072 plays a key role in the regulation of both abiotic and hormone signaling, induced by ABA, methyl jasmonate (MeJA), and salicylic acid (SA), in addition to salt and drought stresses .…”

“…(Zhu et al, 2015), Populus trichocarpa L. (Hu et al, 2010), Setaria italica (L.) P. Beauv. (Puranik et al, 2013), and Miscanthus lutarioriparius Liu ex Chen & Renvoize ( Ji et al, 2014;Yang et al, 2015). Although, NAC genes studies have been extensively studied in model plants or crop species, such as Arabidopsis, soybeans, grapevines, and rice, the identification and functional characterization of stress-related NAC TFs from other plants remains interesting and would provide more insights in revealing the mechanism of NAC-regulated biological processes.…”