Physiological and transcriptional responses to salt stress in salt‐tolerant and salt‐sensitive soybean (Glycine max[L.] Merr.) seedlings

Abstract

Excess salinity is a major environmental threat to agriculture. However, the adaptive mechanisms underlying salt tolerance in soybean (Glycine max [L.] Merr.) remain unclear. The aim of this study was to investigate the differences between salt‐tolerant and salt‐sensitive soybeans in their physiological characteristics and the expression patterns of 8 cation antiporters under salt stress. The inhibitory effects of salt stress on growth and photosynthesis in salt‐sensitive soybean were stronger than those in salt‐tolerant soybean. The concentration of phosphate and most other ions in the seedlings significantly declined under a 150‐mM‐NaCl treatment. Relative K+, Mg2+, and P concentrations were significantly positively correlated with relative net photosynthetic rate. GmNHX1 (Glyma.10G158700) and GmNcl1 (Glyma.03g171500) had similar expression patterns in the salt‐tolerant and salt‐sensitive cultivars. Furthermore, a significant correlation was present between the transcript levels of these 2 genes and the Na+ concentration in soybean leaves. In addition to GmSALT3, which is the major gene in soybean for salt tolerance in previous studies, GmNHX1 and GmNcl1 may be associated with salt tolerance in soybean to some extent. The salt‐tolerant cultivars in this study maintained higher K+, Mg2+, and P concentrations in the leaf and had higher photosynthetic rates than the salt‐sensitive cultivar did under salt stress. These findings can provide theoretical references for the molecular breeding of salt‐tolerant soybean and the sustainable use of saline soils.

Low pH alleviated salinity stress of ginger seedlings by enhancing photosynthesis, fluorescence, and mineral element contents

“…These results suggest that the reason for photosynthesis under salt stress alone is nonstomatal limitation. Similar results were reported previously ( Feng et al, 2014 ; Ning et al, 2018 ) However, low pH with salt stress reduced the Ci and increased the Pn; Gs; and the activities of Rubisco, FBA and FBP. Taken together, these results indicated that low pH could protect photosynthetic structures and increase the photosynthesis enzyme activities, thereby increasing the photosynthesis rate.…”

Chitosan Modified Biochar Increases Soybean (Glycine max L.) Resistance to Salt-Stress by Augmenting Root Morphology, Antioxidant Defense Mechanisms and the Expression of Stress-Responsive Genes

“…The beneficial effect of CMB (extent of the decline in sodium accumulation) was significantly greater than with BR. Ning et al [ 34 ] demonstrated that soybean plants require more photosynthetic products in roots under saline stress to absorb sufficient moisture and nutrients to sustain regular growth. Under salt stress conditions, most of the energy acquired by photosynthesis and fixed into carbon compounds are used by plants for general maintenance, whereas only a small proportion (10–40%) is used directly for biomass accumulation [ 4 ].…”

“…After harvesting and washing with deionized water, the root and leaf of soybean plants were separated. The sodium ion concentration measurement followed the procedure of [ 34 ]. Briefly, soybean leaves and roots were ground in an IKA mill (A11 basic, IKA) to a powder with uniform particle size.…”

Towards sustainable agriculture for the salt‐affected soil

“…Abdel Latef, Srivastava, El‐sadek, Kordrostami, and Lam‐Son Phan Tran () applied titanium dioxide nanoparticles to enhance tolerance of broad bean plants under saline soil, obtaining good effects and providing new ideas to improve salt‐affected soil in combination with bean planting. Ning, Kan, Shao, and Yu () investigated transcriptional responses to salt stress in salt‐tolerant and salt‐sensitive soybean ( Glycine max [L.] Merr.) seedlings and got two important salt‐tolerant genes (GmNHX1 and GmNcl1), providing potential base for biotechnologically breed soybean to meet salt‐resistant planting.…”