**8. Conclusion and prospects**

Over exploitation of groundwater, the use of irrigation water with high salt content, and the application of salt-based pesticides and fertilizers have all contributed to soil salinization, a major problem for environmental and socioeconomic sustainability in many parts of the world. Salinization occurs when salt concentrations in the soil become elevated, leading to a decrease in soil fertility and crop yields. This is often caused by the accumulation of salts in the soil, either due to a lack of leaching or due to the application of salt-based fertilizers and pesticides. The over-extraction of groundwater can also lead to the accumulation of salts in the soil as the water may

contain a higher concentration of salts than the soil. In addition, irrigation with water that has a high salt content can lead to the accumulation of salts in the soil. To prevent soil salinization, proper irrigation management, the use of low-salt fertilizers and pesticides, and the proper management of groundwater extraction are all essential. Soil salinization is a problem for both terrestrial and aquatic ecosystems, causing problems for plants, animals, and people. Plants are able to adapt their metabolic processes and physiological activities in order to survive in environments with high levels of salt. This can inhibit plant growth, but plants are able to overcome this obstacle by changing the way they assimilate and use nutrients. When exposed to high levels of salt, plants have evolved mechanisms to adapt their metabolism and preserve physiological processes such as changing the expression of genes involved in ion transport and osmotic adjustment. In addition, plants can upregulate the expression of genes involved in antioxidant enzymes, which help protect the plant from oxidative damage caused by high salinity. Plants also increase the expression of genes involved in the synthesis of compatible solutes, which are osmotically active molecules that increase the osmotic potential of the cell and allow it to retain water. Lastly, plants can reduce their transpiration rates and close their stomata to reduce water loss. It is possible to do this by regulating the expression of genes involved in ion transport and osmotic balance. The expression of genes involved in ion transport and osmotic balance under soil salinity is to introduce a salt stress response gene. A salt stress response gene encodes a transcription factor that responds to salinity stress by upregulating the expression of ion transport and osmotic balance-related genes. This upregulation helps the plant to better cope with stress and improve its overall growth and survival.

There are a number of prospects to control soil salinity using secondary metabolites. Some of these include using antimicrobial agents to control bacterial populations, using plant-derived secondary metabolites to regulate salt uptake, and using plant-derived inhibitors of salinization enzymes. There are several secondary metabolites that have been shown to have the ability to mitigate the effects of soil salinity on plant growth. For example, polyamines such as spermidine and spermine have been found to reduce the toxic effects of salt on plant cells by maintaining ion homeostasis and reducing oxidative stress. Another group of secondary metabolites that have been studied for their potential to control soil salinity are plant growth regulators such as auxins, cytokinins, and gibberellins. These compounds have been found to improve plant growth and productivity under saline conditions by regulating the uptake and distribution of ions, maintaining water balance, and enhancing antioxidant defense mechanisms. In addition to polyamines and plant growth regulators, other secondary metabolites, such as flavonoids, alkaloids, and terpenoids, have also been shown to have potential for controlling soil salinity. These compounds have been found to improve plant growth and productivity by reducing oxidative stress, enhancing nutrient uptake, and regulating ion balance. Soil salinity can have a significant impact on plant metabolism and growth, leading to stunted growth and decreased yields that need to be minimized in the future forecast.

*Plant Adaptation to Salinity Stress: Significance of Major Metabolites DOI: http://dx.doi.org/10.5772/intechopen.111600*
