Maize (Zea mays L.) responses to salt stress in terms of root anatomy, respiration and antioxidative enzyme activity

Abstract

Background Soil salt stress is a problem in the world, which turns into one of the main limiting factors hindering maize production. Salinity significantly affects root physiological processes in maize plants. There are few studies, however, that analyses the response of maize to salt stress in terms of the development of root anatomy and respiration. Results We found that the leaf relative water content, photosynthetic characteristics, and catalase activity exhibited a significantly decrease of salt stress treatments. However, salt stress treatments caused the superoxide dismutase activity, peroxidase activity, malondialdehyde content, Na+ uptake and translocation rate to be higher than that of control treatments. The detrimental effect of salt stress on YY7 variety was more pronounced than that of JNY658. Under salt stress, the number of root cortical aerenchyma in salt-tolerant JNY658 plants was significantly higher than that of control, as well as a larger cortical cell size and a lower root cortical cell file number, all of which help to maintain higher biomass. The total respiration rate of two varieties exposed to salt stress was lower than that of control treatment, while the alternate oxidative respiration rate was higher, and the root response of JNY658 plants was significant. Under salt stress, the roots net Na+ and K+ efflux rates of two varieties were higher than those of the control treatment, where the strength of net Na+ efflux rate from the roots of JNY658 plants and the net K+ efflux rate from roots of YY7 plants was remarkable. The increase in efflux rates reduced the Na+ toxicity of the root and helped to maintain its ion balance. Conclusion These results demonstrated that salt-tolerant maize varieties incur a relatively low metabolic cost required to establish a higher root cortical aerenchyma, larger cortical cell size and lower root cortical cell file number, significantly reduced the total respiration rate, and that it also increased the alternate oxidative respiration rate, thereby counteracting the detrimental effect of oxidative damage on root respiration of root growth. In addition, Na+ uptake on the root surface decreased, the translocation of Na+ to the rest of the plant was constrained and the level of Na+ accumulation in leaves significantly reduced under salt stress, thus preempting salt-stress induced impediments to the formation of shoot biomass.

Genome-wide identification of key genes responding to salt stress in Populus alba

“…And a large amount of MDA will be produced [19]. High concentration of MDA will disrupt the structure and integrity of cell membrane, and lead to the increase of cell membrane permeability [19,20]. This study found that the MDA content in leaves was higher than that in roots under salt stress (Fig.…”

Systematic assessment of salt tolerance based on morpho-physiological traits and genes related in inbred rice lines at the seedling stage

“…Mung bean tolerance to salinity is related to physiological processes in the plant. Previous studies revealed that the level of tolerance of mung bean to salinity is related to membrane permeability and cell osmotic pressure (Nawaz et al 2021;Al Murad et al 2023), its ability to accumulate K (Hao et al 2021;Joshi et al 2022), its ability to inhibit Na translocation from root to shoot (Hu et al 2022), its ability to accumulate water in leaves, proline and glycine betaine, and inhibit chlorophyll degradation (Shafi et al 2019;Sofy et al 2020;). Tolerance in mung beans is also related to enzymatic reactions in the cell.…”

Salinity Stress in Maize: Consequences, Tolerance Mechanisms, and Management Strategies

“…Salinity stress considerably reduced the grain yield of maize by decreasing the number of grains and grain weight during the reproductive growth stage [81]. Reduced photosynthesis and photoassimilates under saline stress are the major causes of poor grain formation, decreasing grains and grain weight [82], and poor biomass production [83]. Poor grain setting and filling at the reproductive stage owing to reduced translocation of assimilates from source to developing grains (sink) under salt stress ultimately reduced grain yield [84].…”