Response to Salinity in Legume Species: An Insight on the Effects of Salt Stress during Seed Germination and Seedling Growth

Abstract

The process of soil salinization and the preponderance of saline water sources all over the world represent one of the most harmful abiotic stress to plant growth. This pointed to the importance of obtaining plants which are tolerant or resistant to salt, considering that projection of climate change for the coming years indicate an increase in temperature and rain scarcity. In the current study, the effect of NaCl was investigated on germinating seeds of Lathyrus sativus L., Vicia sativa L., Vigna radiata L. R.Wilczek and Vigna unguiculata L. Walp., by combining physiological, biochemical, biostatistical and ultrastructural analyses. Our results revealed that germination was not influenced by high NaCl concentrations, while seedling growth was affected even at low NaCl concentrations, probably due to an alteration in water uptake and in organic matter biosynthesis. Nevertheless, the synthesis of antioxidant enzymes, phenolic acids and flavonoids was registered in all species, which tended to cope with the increasing salt stress, allowing a response mechanism such as cytoplasm detoxification and cellular turgor maintenance. Besides, the ultrastructural analysis evidenced plasmolyzed cells close to cells with a normal ultrastructure with no appreciable differences among the species. This research deeply investigates the mechanism of salt‐stress response focusing on species never tested before for their possible tolerance to salinity.

Rising Shallow Groundwater Level May Facilitate Seed Persistence in the Supratidal Wetlands of the Yellow River Delta

“…A possible reason for these results is that high salinity played a role in inhibiting microbial activity ( Whittle et al, 2022 ) under moist conditions to maintain higher seed viability. In addition, it was possible that salt stress triggered an increase in the phenolic compounds and flavonoids level ( Tlahig et al, 2021 ) to protect seeds from microorganisms, and this stress may contribute to antioxidant defense under conditions similar to those in the aging experiment as mentioned above. This conclusion was supported by the interaction between groundwater level and salinity.…”

The effect of salinity stress on germination parameters in Satureja thymbra L. (Lamiaceae)

“…Salinity tolerance and response mechanisms differ according to many parameters such as salt exposure time, salt concentration, plant genotypes and environmental factors. In some plant species and varieties, stress factors cause a lot of damage, while in others, the level of this damage is less (Babalik & Göktürk Baydar, 2021;Tlahig et al, 2021;Tokarz et al, 2021). Since most crops are sensitive to salinity, an increase in salt content causes yield loss.…”

Molecular mechanisms of flavonoid accumulation in germinating common bean (Phaseolus vulgaris) under salt stress

“…However, abiotic stress (e.g., drought, salt, and cold) can affect the flavonoid biosynthetic pathway by regulating flavonoid transport and the expression and accumulation of related proteins, finally affecting the flavonoid content in plants ( 17 ). Previous studies have shown that salt stress significantly inhibits the germination of legume crops (including Lathyrus sativus, Vicia sativa, Vigna radiata , and Vigna unguiculata ) but increases the flavonoid content in their seeds ( 18 ). Besides, another study reported significant differences in the flavonoid content and anti-inflammatory effects of soybean when seeds were germinated under different abiotic stress treatments ( 19 ).…”

“…It has also been reported that abiotic stress could increase the content of total phenolic compounds and total flavonoids in soybean ( Glycine max ) and mung bean ( V. radiata ) sprouts ( 19 , 20 ). Therefore, the regulation of flavonoid biosynthesis is considered an important regulatory mechanism of legume crops in response to salt stress ( 18 ). In another study, Gu et al ( 21 ) demonstrated that moderate drought stress treatment could increase flavonoid content in plants.…”