Identification and characterization of the GmRD26 soybean promoter in response to abiotic stresses: potential tool for biotechnological application

Abstract

BackgroundDrought is one of the most harmful abiotic stresses for plants, leading to reduced productivity of several economically important crops and, consequently, considerable losses in the agricultural sector. When plants are exposed to stressful conditions, such as drought and high salinity, they modulate the expression of genes that lead to developmental, biochemical, and physiological changes, which help to overcome the deleterious effects of adverse circumstances. Thus, the search for new specific gene promoter sequences has proved to be a powerful biotechnological strategy to control the expression of key genes involved in water deprivation or multiple stress responses.ResultsThis study aimed to identify and characterize the GmRD26 promoter (pGmRD26), which is involved in the regulation of plant responses to drought stress. The expression profile of the GmRD26 gene was investigated by qRT-PCR under normal and stress conditions in Williams 82, BR16 and Embrapa48 soybean-cultivars. Our data confirm that GmRD26 is induced under water deficit with different induction folds between analyzed cultivars, which display different genetic background and physiological behaviour under drought. The characterization of the GmRD26 promoter was performed under simulated stress conditions with abscisic acid (ABA), polyethylene glycol (PEG) and drought (air dry) on A. thaliana plants containing the complete construct of pGmRD26::GUS (2.054 bp) and two promoter modules, pGmRD26A::GUS (909 pb) and pGmRD26B::GUS (435 bp), controlling the expression of the β-glucuronidase (uidA) gene. Analysis of GUS activity has demonstrated that pGmRD26 and pGmRD26A induce strong reporter gene expression, as the pAtRD29 positive control promoter under ABA and PEG treatment.ConclusionsThe full-length promoter pGmRD26 and the pGmRD26A module provides an improved uidA transcription capacity when compared with the other promoter module, especially in response to polyethylene glycol and drought treatments. These data indicate that pGmRD26A may become a promising biotechnological asset with potential use in the development of modified drought-tolerant plants or other plants designed for stress responses.

Two homologous LHY pairs negatively control soybean drought tolerance by repressing the abscisic acid responses

“…However, the regulation of the drought response in soybean remains poorly understood. It was reported that overexpressing the orthologues of Arabidopsis ABA‐responsive genes in soybean, such as GmMYB84 , GmWRKY12 , GmWRKY54 and GmRD26 , could enhance ABA signaling and confer drought tolerance (Wang et al ., 2017; Shi et al ., 2018; Freitas et al ., 2019; Wei et al ., 2019). However, these regulations usually occurred in the downstream position, particularly on downstream transcriptional factors.…”

Characterization of PtAOS1 Promoter and Three Novel Interacting Proteins Responding to Drought in Poncirus trifoliata

“…Investigations of promoters help to understand the specificity mechanism of plant genes responding to abiotic stresses. For example, the GmRD26 (a NAC transcription factor) promoter has been characterized as being involved in stress and ABA response; ABRE motifs and ABA responsive elements were thought to be the key factor influencing the stress-responsive gene expression regulated by GmRD26 under drought stress [ 39 ]. In transgenic tobacco, disruption of an E-box/ABRE-like motif in the storage protein napA promoter led to the complete abolishment of reporter gene expression, suggesting that E-box is a core motif conferring napA promoter activity [ 40 ].…”

GmPAP12 Is Required for Nodule Development and Nitrogen Fixation Under Phosphorus Starvation in Soybean

“…Total proteins of transgenic soybean root nodules were extracted and quantified as previously described (Freitas et al, 2019). GUS assay was performed in a mixture containing 10 mM of 4-methylumbelliferyl-β-D-glucuronide (MUG; Sigma, United States), and the mixture was incubated for 1 h at 37 • C. The fluorescence product of 4-methylumbelliferone (4-MU) was monitored using a VersaFluor Fluorometer (Bio-Rad) with excitation at 365 nm and emission at 455 nm.…”