Nitric oxide signaling pathway in medicinal plants

Abstract

Nitrogen monoxide or nitric oxide is a biological active growth regulator that a wide range of studies have recently shown that it acts as a growth regulator (signaling molecule) in plants. As soon as Nitric Oxide (NO) known as a new biological agent in plants and animals, biological branches of sciences like medicine, biochemistry, physiology and genetics have paid special attention to it. NO is a very reactive gas shape free radical which has attracted much attention during recent years. This compound is produced by the plant and it has increased the shelf life of some fruits, vegetables and cut flowers in low concentrations. NO is mostly synthesized from enzymatic and non-enzymatic pathways whose enzymatic biosynthesis pathway is done by reductase nitrate biosynthesis pathway through the cytosol, also it is known as an important and very reactive signaling molecule with short life which is produced by a group of enzymes known as synthesize NO which transforms L-arginine to L-citrulline and NO. It has been revealed that plants use NO as a growth regulator which regulates and modifies antimicrobial defensive responses. Recently, it has been approved that this material plays a vital role in regulating the normal physiological activities of plants such as pores closing, aging, increasing the vase life of cut flowers after harvesting, respiration and photosynthesis, antioxidant enzymes activities and growth.