Expression of a grape bZIP transcription factor, VqbZIP39, in transgenic Arabidopsis thaliana confers tolerance of multiple abiotic stresses

Abstract

The basic region/leucine zipper (bZIP) transcription factors are known to play key roles in response to abiotic stress. In this study, a bZIP gene (VqbZIP39) was isolated from grape (Vitis quinquangularis) and constitutively expressed in Arabidopsis under control of the cauliflower mosaic virus 35S promoter. The transgenic Arabidopsis thaliana plants showed enhance salt and drought stress tolerance during seed germination and in the seedling and mature plant stages. Various physiological parameters related to stress responses were analyzed to gain further insight into the role of VqbZIP39 and it was found that osmotic stress caused less damage to the transgenic seedlings than to the corresponding wild type plants. This correlated with an increase in endogenous ABA content as a consequence of the constitutive overexpression of VqbZIP39, and the up-regulated expression of stress-inducible target genes associated with tolerance of drought, high-salt, and oxidative stresses. Our results suggest that the expression of VqbZIP39 in A. thaliana likely enhances the tolerance to multiple abiotic stresses through the ABA signaling pathway, and may therefore have a similar function in the response to abiotic stresses in grape.

Improvement of drought tolerance by overexpressing MdATG18a is mediated by modified antioxidant system and activated autophagy in transgenic apple

“…Plants utilize both enzymatic and nonenzymatic mechanisms for scavenging ROS (Cheng et al, 2016;Shigeoka et al, 2002;Wang et al, 2015a;Zhou et al, 2013). For example, under drought treatment, overexpression of VqbZIP39 in Arabidopsis increases the activities of CAT, POD and SOD (Tu et al, 2016). Overexpression of MdcyMDH also enhances SOD and CAT activities in transgenic apple callus and in transformed tomato plants (Yao et al, 2011).…”

VlbZIP30 of grapevine functions in drought tolerance via the abscisic acid core signaling pathway

“…1). A phylogenetic analysis indicated that VlbZIP30 is most closely related to the group A ABF/DPBF TFs, which have previously been shown to be involved in ABA and drought stress signaling in A. thaliana (Kang et al , 2002; Kim et al , 2002; Fujita et al , 2005; Yoshida et al , 2015), and in grapevine (Nicolas et al , 2014; Tu et al , 2016a) (Fig. 2A).…”

“…Interestingly, ABF2/bZIP39 (VIT_18s0001g10450), which was characterized as being involved in ABA signaling in grapevine cell culture, has been reported to transiently trans-activate the expression of NAC17 (VIT_19s0014g03290) and PUB19 (VIT 17s0000g08080) following ABA treatment (Nicolas et al , 2014; Pilati et al , 2017). In addition, overexpression of this gene in A. thaliana enhances tolerance to drought stress through the ABA signaling pathway (Tu et al , 2016a), suggesting that NAC17 and PUB19 may enhance drought stress in grapevine.…”

“…The relative electrolyte leakage, MDA content and antioxidant enzyme activity were measured as previously described (Tu et al , 2016b), as was ABA content (Tu et al , 2016a). Histochemical staining procedures were used to detect in situ reactive oxygen species (ROS) levels and dead cells as previously described (Tu et al , 2016b).…”

“…Several, such as CBF1/2/3/4 (Xiao et al , 2006; Siddiqua and Nassuth, 2011; Li et al , 2013), WRKY11 (Liu et al , 2011a), ERF1/2/3 (Zhu et al , 2013), NAC26 (Fang et al , 2016), and PAT1 (Yuan et al , 2016), have been identified and their overexpression in A. thaliana has been shown to enhance drought resistance. However, to date, only a few grapevine bZIP TFs have been functionally characterized during a drought stress response (Gao et al , 2014; Tu et al , 2016a, b), and their regulatory mechanisms are not well understood.…”