Table 1 Biochemical and physiological responses of plants to salinity stress
From: Salinity tolerance mechanisms and their breeding implications
Sr. no. | Plant traits | Yield-related impacts on plant | Variation in stress | References |
|---|---|---|---|---|
1 | Plants root growth | Inhibition of nutrients and water absorption | Stress lowers the osmotic potential of plant roots. | [30] |
2 | Leaf tissues | Necrosis and chlorosis | Salt in the cells produce toxicity, and antioxidant helps in lowering the toxicity. | [30] |
3 | Leaf anatomy | Impact on leaf tissue | Reduction in the epidermis and mesophyll thickness as well as decrease in the intercellular spaces | [31] |
4 | Oxidative damage | Cellular toxicity due to production of reactive oxygen species (ROS) | Plants having antioxidant activity tolerate this oxidative damage. | [31] |
5 | Osmotic potential | Accumulation of salt in the leaves cause injury to the leaves and roots of the plants. | Halophytes tolerate the salt stress by accumulation of salt in the leaves by modifying the osmotic potential but not glycophytes as they are less tolerant to salt. | [32] |
6 | Photosynthesis and photosynthetic pigments | Reduced photosynthetic capacity | Closing of the stomata by subjection of plant to salt for a short time increases the tolerance of plant to salt stress. | [33] |
7 | Gaseous change characteristics | Salt stress notably decreased the few gaseous changes characteristics like water use efficiency, transpiration rate, etc. in some cultivars of sunflower. | Salt concentration improves the chlorophyll ratio a/b as the amount of chlorophyll b may be transformed into chlorophyll a in the course of the process of degradation resulting in the increased concentration of chlorophyll a. | |
8 | Reproductive development | Salinity caused sterility in some plants. | In response to salinity, plants modify itself by inducing early flowering and prevention of lateral shoot development. | [35] |
9 | Hormones | Increased concentration of ABA | Enhanced amount of ABA during salt stress attenuates the repressive effect of salinity on growth as well as translocation of assimilates. | |
10 | Amino acids | Decrease in the concentration of amino acids such as methionine, arginine, and cystine. | Increase in the amount of proline in response to salt stress | [37] |
11 | Carbohydrates | Agglomeration of trehalose, fructose, glucose, fructans, and starch. | In the carbon storage, osmoprotection and scavenging of ROS, these carbohydrates play a role in salt stress conditions. |