Regulatory Role of Mineral Nutrients in Nurturing of Medicinal Legumes Under Salt Stress

Abstract

Medicinal legumes (Fabaceae family) bear primary and secondary metabolites and other important compounds such as nutraceuticals, pharmaceuticals, and other useful products. The medicinal legumes are potential sources of glycosides (aloe-emodin, chrysophenol, emodin, rhein, etc.), antibiotics, flavonoids, alkaloids and phytochemicals. Hence, it is the need of the hour to escalate the yield and quality of these legumes. In fact, balanced nutrition of crop plants plays a vital role in sustaining the yield and quality of medicinal plants together with maintaining the fertility status of soils on long-term basis. The role of mineral nutrition is of vital importance in the cultivation of these plants. The yield of most crop plants increases linearly with the amount of fertilizers absorbed. With a balanced mineral nutrients supply, the maximum genetic potential of plants can be realized successfully. The productivity as well as the quality of a crop is affected by environmental factors; the uptake and utilization of mineral nutrients from the soil, or from the fertilizers applied to the plants is of prime importance. Among the macro-nutrients, nitrogen (N), phosphorus (P), potassium (K) and calcium (Ca) are major components of metabolic molecules that affect the growth and metabolism of plants significantly. They also play important structural and physiological roles in the overall development of plants. On the other hand, out of many crop production strategies, foliar application of mineral fertilizers in the form of aqueous sprays is also a successful method of administering it. Salinity is a major cause of decrease in agricultural productivity and the increasing level of salt accumulation in soils has become an exigent issue for Indian soils. However, as in the majority of cultivated plants, growth and yield of medicinal plants can be affected by environmental constraints such as salinity and drought. The above technique could be applied to ameliorate the productivity and quality of these medicinal legumes under salinity stress. This review covers the possible role of mineral nutrients application on selected medicinal legumes as well as their ameliorative effects on these legumes under salt stress.