What Is Plant Adaptations And Responses To Salinity Stress?

Plant Adaptations and Responses to Salinity Stress Despite the high salt stress applied, higher plants are able to adapt to these conditions. Salt exclusion and inclusion by higher plants serve as a response to high salinity. With the capability to exclude the salts, negative effects on the entire plant and certain organs are prevented or reduced. Due to the selectively permeable membranes of the plant, K+ are absorbed rather than Na+ leading to low Na+ levels and Cl- content in the plant. Meanwhile, halophytes or salt accumulators have the capacity to survive in high salt concentrations. This was made possible through the salt resistant cell membranes wherein there is a high Na+ to K+ ratio and the removal of excess salt entering
In addition, these halophytes also have the capacity to remove the accumulated salts in the water they uptake from the surface layer of the soil. Among the notable characteristics of these plants are its specialized leaf cells that excrete salt which are called salt glands while others have salt hairs located in their stem to excrete the salt. Moreover, this family of plants are able to adapt through the regulation of the transpiration brought about by the sodium ion that influences the opening and closing of guard cells in order to adjust to the salt present in the environment (Ashour et al., 2002). Thus, according to Jouyuban 2012, these plant responses and adaptations are important for the improvement of crop growth and production. In another study conducted by Rewald etal 2013 that focused on the varying effects of the salinity of the soil on the root morphology, anatomy and physiology of plants, it was proved that certain species of plants develop tolerance to salinity of the soil that are dependent on the combination of regulative and protective traits above and below ground on the cellular level to tissue and organ functions. The
2011). Among these phytohormones are abscisic acid (ABA), indole-3-acetic acid (IAA) and cytokinins (CK) which are closely related to nitrogen signaling (Kiba et al. 2011). ABA is a phytohormone synthesized in almost all cells containing amyloplast or chloroplast and can be detected in living tissue from root to shoot tip. It has been observed that salinity increases the plants ABA concentration leading to the response of the plant for water stress through inducing the closing of the stomata. Nitrogen, a macronutrient present in many key biological molecules as NO3- and NH4+, influences plant development as well. In decreasing levels of nitrogen supply for the plant, the plant is able to respond both in physiological and morphological levels in order to adjust the growth and development of the plant. Based on previous studies cited by Rewald, et al, (2010) there was a correlation and interaction happening between nitrogen and cytokinin in several plant species. This interaction initiated the morphological response, protein synthesis capacity and macronutrient acquisition (Sakakibara et al.