Expression pattern of drought stress marker genes in soybean roots under two water deficit systems

Abstract

The study of tolerance mechanisms for drought stress in soybean is fundamental to the understanding and development of tolerant varieties. Using in silico analysis, four marker genes involved in the classical ABA-dependent and ABA-independent pathways of drought response were identified in the Glycine max genome in the present work. The expression profiles of the marker genes ERD1-like, GmaxRD20A-like, GmaxRD22-like and GmaxRD29B-like were investigated by qPCR in root samples of drought sensitive and tolerant soybean cultivars (BR 16 and Embrapa 48, respectively), submitted to water deficit conditions in hydroponic and pot-based systems. Among the four putative soybean homologs to Arabidopsis genes investigated herein, only GmaxRD29B-like was not regulated by water deficit stress. Distinct expression profiles and different induction levels were observed among the genes, as well as between the two drought-inducing systems. Our results showed contrasting gene expression responses for the GmaxRD20A-like and GmaxRD22-like genes. GmaxRD20A-like was highly induced by continuous drought acclimating conditions, whereas GmaxRD22-like responses decreased after abrupt water deprivation. GmaxERD1-like showed a different expression profile for the cultivars in each system. Conversely, GmaxRD20A-like and GmaxRD22-like genes exhibited similar expression levels in tolerant plants in both systems.

Improving water use efficiency by changing hydraulic and stomatal characteristics in soybean exposed to drought: the involvement of nitric oxide

“…Throughout this study, we analyzed the response of soybean cultivars to WD and the mechanisms associated with increasing tolerance to this stress triggered by NO. Generally, our results are in agreement with previous studies indicating that cultivar EMBRAPA 48 presents higher tolerance to WD than cultivar BR 16 (Neves-Borges et al 2012, Marcolino-Gomes et al 2013, Arraes et al 2015. In fact, when subjected to WD, plants of cultivar EMBRAPA 48 were able to maintain their biomass, productivity, and photosynthetic rates at levels remarkably higher than those observed for BR 16.…”

Water Stress Modulates Soybean Aphid Performance, Feeding Behavior, and Virus Transmission in Soybean

“…Plant dry weight measured at the end of the experiment also showed the same pattern ( P < 0.001) except there was no difference in dry weight between well-watered and saturated plants ( Figure 1B ). The expression of a drought-stress marker, RD20A ( Neves-Borges et al, 2012 ), 3 days after the commencement of water stress, treatments showed a significant increase in expression under drought stress as compared to well-watered and saturated plants (Supplementary Figure S2 ). Feeding by either non-viruliferous or viruliferous aphids did not affect plant water content or dry weight in response to the water-stress treatments (Data not shown).…”

Proteomic and Metabolomic Analysis of a Drought Tolerant Soybean Cultivar from Brazilian Savanna

“…A lower perturbation level of the metabolic pathways for the Embrapa 48 was observed. This behavior was also found in the gene expression profiles and suggests a lack of adaptive traits, which are important for the plants resistance to drought in the sensitive genotype [18]. Another explanation could be the occurrence of damage-related responses that may not have been induced in the tolerant cultivar under the same stress level.…”

“…The results showed that the Embrapa 48 cultivar may be characterized as drought-tolerant and the BR 16 cultivar as droughtsensitive. Physiological responses and gene expression profiles were also evaluated to understand the mechanism of tolerance for these cultivars [17,18]. Until now, no studies have investigated proteome and metabolome, so this research can lead to a new understanding of the contrasting molecular mechanisms for drought tolerance between these genotypes that share a common ancestor.…”