ABSTRACT
One of the most important stresses is nutrient stress. Essential mineral nutrients play key roles in many aspects of plant metabolism, growth, and development. There is, therefore, a very wide spectrum of responses to nutrient stresses. Although most nutrient stresses decrease the plant growth rate, the effects on metabolic processes differ between nutrients. For some nutrients, changes in the rates of specific assimilatory and biochemical reactions are the predominant responses to a deficiency of that nutrient. Plants require large amounts of nitrogen for the biosynthesis of amino acids, nucleic acids, proteins, and secondary metabolites. In agricultural soils, nitrate is the dominant form of nitrogen, essential for plant growth and productivity. Boron-deficient plants exhibit various noticeable symptoms in their vegetative and reproductive organs. The scarcity of boron firstly reduces the elongation of growing points due to limited cell wall deposition and then induces necrosis of root tissues due to cell death.
