Drought Tolerance Responses in Vegetable-Type Soybean Involve a Network of Biochemical Mechanisms at Flowering and Pod-Filling Stages

Abstract

Severe drought stress affects the production of vegetable-type soybean (Glycine max L. Merrill), which is in infancy for Africa despite its huge nutritional benefits. This study was conducted under controlled environmental conditions to establish the effects of severe drought stress on ascorbate peroxidase (APX), guaiacol peroxidase (GPX), and glutathione reductase (GR) activities as well as proline, total soluble sugars (TSS), and hydrogen peroxide (H2O2) contents of five vegetable-type soybean cultivars (UVE8, UVE14, UVE17, AGS354, AGS429) at flowering and pod-filling stages. Drought induced significant increases in the contents of proline (selectively at pod filling for AGS429), TSS (at both stages for AGS429, and only at pod filling for UVE14), and malondialdehyde (AGS354 at flowering; UVE17 at pod filling). UVE8 and AGS354 had the highest H2O2 levels at flowering under drought stress, while AGS429 had the lowest. However, AGS429 was the only cultivar with significantly increased H2O2 under drought stress. Furthermore, drought stress induced significant increases in APX, GPX, and GR activities at flowering for AGS429. AGS354 recorded the highest decline for all antioxidative enzymes, while UVE17 decreased for GPX only. All biochemical parameters, except H2O2, were significantly higher at pod filling than at the flowering stage. The relationship between H2O2 and total seed mass (TSMP) or total seed per plant (TSP) was significantly positive for both stages, while that of TSS (at flowering) and proline (at pod filling) were significantly related to total pods per plant (TPP). The study suggests that during drought, the tolerance responses of vegetable-type soybean, APX, GPX, and GR (especially at the flowering stage), function in concert to minimize H2O2 production and lipid peroxidation, thereby allowing H2O2 to function in the signaling events leading to the induction of drought tolerance. The induction of TSS at flowering and proline at pod filling is important in the drought tolerance response of this crop.

Genome-Wide Variation Analysis of Four Vegetable Soybean Cultivars Based on Re-Sequencing

“…In this study, 16 and 10 genes were associated with sucrose and starch metabolic processes, respectively, some of which might play a role in sucrose and starch metabolism. A number of SNPs are reportedly associated with sucrose and protein contents [ 8 , 26 , 27 ]. Once confirmed, the differences could provide an insight into breeding selection of vegetable soybean as well as the loss of function of genes that may have a key role in grain soybean.…”

“…The frequent usage of limited elite lines may lead to a relatively narrowed genetic background of vegetable soybean [ 20 , 21 ]. The development of related markers and the mining of specific genes can provide marker resources for molecular-marker-assisted breeding and further reveal the genome composition of the two soybean types [ 27 , 28 ]. This will have an important guiding significance for the classification of vegetable soybean breeding, and can effectively improve the directivity of vegetable soybean breeding and promote the development of the vegetable soybean industry.…”

The Physiological and Biochemical Responses of European Chestnut (Castanea sativa L.) to Blight Fungus (Cryphonectria parasitica (Murill) Barr)

“…Most research has focused primarily on plant responses to abiotic stress [27,[39][40][41][42], but there is also an increasing number of studies that also examine some form of biotic stress factors [11,[43][44][45]. The crops included in the experiments come primarily from the most important crops, such as maize.…”

“…Furthermore, the reactive oxygen species (ROS) in plants, despite their destructive effects, are secondary indicators [26]. When plants produce ROS moderately, they may indicate stress tolerance, e.g., induced hydrogen peroxide improved the drought tolerance responses in soybeans [27]. Under oxidative stress conditions caused by biotic stressors, the activity of antioxidant enzymes, including superoxide dismutase (SOD), guaiacol peroxidase (GPX), and ascorbate peroxidase (APX), are increasing [25,28].…”

Identification of effective Rhizobium isolate(s) for efficient symbiosis with soybean under moisture stress conditions

“…Further, the drought stress affects the performance of soybean, which must be clarified for minimizing the threat of climate change to global food security. The effects of moisture are significant on soybean germination, plant respiration, chlorophyll content, leghemoglobin, proline, flowering, gene expression, seed development, and seed quality (Moloi et al, 2021;Arya et al, 2021). Nonetheless, there are only a few reports on the effects of drought stress exerted on root morphology safety (Pantalone et al, 1996).…”