GmWRKY16 Enhances Drought and Salt Tolerance Through an ABA-Mediated Pathway in Arabidopsis thaliana

Abstract

The WRKY transcription factors (TFs) are one of the largest families of TFs in plants and play multiple roles in plant development and stress response. In the present study, GmWRKY16 encoding a WRKY transcription factor in soybean was functionally characterized in Arabidopsis. GmWRKY16 is a nuclear protein that contains a highly conserved WRKY domain and a C2H2 zinc-finger structure, and has the characteristics of transcriptional activation ability, presenting a constitutive expression pattern with relative expression levels of over fourfold in the old leaves, flowers, seeds and roots of soybean. The results of quantitative real time polymerase chain reaction (qRT-PCR) showed that GmWRKY16 could be induced by salt, alkali, ABA, drought and PEG-6000. As compared with the control, overexpression of GmWRKY16 in Arabidopsis increased the seed germination rate and root growth of seedlings in transgenic lines under higher concentrations of mannitol, NaCl and ABA. In the meantime, GmWRKY16 transgenic lines showed over 75% survival rate after rehydration and enhanced Arabidopsis tolerance to salt and drought with higher proline and lower MDA accumulation, less water loss of the detached leaves, and accumulated more endogenous ABA than the control under stress conditions. Further studies showed that AtWRKY8, KIN1, and RD29A were induced in GmWRKY16 transgenic plants under NaCl treatment. The expressions of the ABA biosynthesis gene (NCED3), signaling genes (ABI1, ABI2, ABI4, and ABI5), responsive genes (RD29A, COR15A, COR15B, and RD22) and stress-related marker genes (KIN1, LEA14, LEA76, and CER3) were regulated in transgenic lines under drought stress. In summary, these results suggest that GmWRKY16 as a WRKY TF may promote tolerance to drought and salt stresses through an ABA-mediated pathway.

Rice OsHSFA3 Gene Improves Drought Tolerance by Modulating Polyamine Biosynthesis Depending on Abscisic Acid and ROS Levels

“…Similarly, OsHSFA3-overexpressing plants maintained higher biomass as compared to WT under drought stress, which further revealed its role in drought tolerance. These observations were in line with previous findings which revealed higher plant biomass and survival ability in drought-tolerant plants [40,52,53]. These findings indicate that OsHSFA3 induces drought tolerance in transgenic plants by different plant adaptations such as longer root length, reduced water loss and modulating the ABA level to protect from dehydration.…”

“…ABA is an important plant stress signaling hormone which plays important role in drought stress tolerance via regulating expression of various stress-responsive genes [31,39,40]. Thus, we measured endogenous ABA levels in OsHSFA3-overexpressing lines and WT plants.…”

Root‐specific NF‐Y family transcription factor, PdNF‐YB21, positively regulates root growth and drought resistance by abscisic acid‐mediated indoylacetic acid transport in Populus

“…, 2018; Ma et al . , 2019). Over the past 2 decades, studies have elucidated the importance of NF‐Ys in plant growth and stress responses, however the physiological and molecular mechanisms of action remain largely unexplored.…”

Heterologous Expression of a Soybean Gene RR34 Conferred Improved Drought Resistance of Transgenic Arabidopsis

“…As shown in Figure 4, under drought condition, expression levels of all these genes were significantly higher in the transgenic lines compared with those in WT by 30% (HSP70B) to nearly 50% (RD29A and LEA14). Studies have reported rapid induction of the stress marker gene RD29A under various abiotic stresses, such as water deficit, and particularly in stress-tolerant plants, thus emphasized its role as indicator for resistance toward drought [71,73,74]. Herein, in correlation with higher resistance to drought of transgenic plants (Figure 2), RD29A expression was also found to be remarkedly induced, suggesting RD29A is one of GmRR34 target for mediating drought responses, through a direct and/or indirect manner.…”

“…Three well-known stress-responsive genes, RD29A, LEA14, and HSP70B, were also selected to examine their expression in our study to gain insights to the molecular function basis of GmRR34. Expression patterns of these genes have been considered important indicators for drought-responsive studies [71,72]. As shown in Figure 4, under drought condition, expression levels of all these genes were significantly higher in the transgenic lines compared with those in WT by 30% (HSP70B) to nearly 50% (RD29A and LEA14).…”