Expression dynamics indicate the role of Jasmonic acid biosynthesis pathway in regulating macronutrient (N, P and K+) deficiency tolerance in rice (Oryza sativa L.)

Abstract

Key message: Expression pattern indicates that JA biosynthesis pathway via regulating JA levels might control root system architecture to improve nutrient use efciency (NUE) and N, P, K+ defciency tolerance in rice. Abstract: Defciencies of macronutrients (N, P and K+) and consequent excessive use of fertilizers have dramatically reduced soil fertility. It calls for development of nutrient use efcient plants. Plants combat nutrient defciencies by altering their root system architecture (RSA) to enhance the acquisition of nutrients from the soil. Amongst various phytohormones, Jasmonic acid (JA) is known to regulate plant root growth and modulate RSA. Therefore, to understand the role of JA in macronutrient defciency in rice, expression pattern of JA biosynthesis genes was analyzed under N, P and K+ defciencies. Several members belonging to diferent families of JA biosynthesis genes (PLA1, LOX, AOS, AOC, OPR, ACX and JAR1) showed diferential expression exclusively in one nutrient defciency or in multiple nutrient defciencies. Expression analysis during developmental stages showed that several genes expressed signifcantly in vegetative tissues, particularly in root. In addition, JA biosynthesis genes were found to have signifcant expression under the treatment of diferent phytohormones, including Auxin, cytokinin, gibberellic acid (GA), abscisic acid (ABA), JA and abiotic stresses, such as drought, salinity and cold. Analysis of promoters of these genes revealed various cis-regulatory elements associated with hormone response, plant development and abiotic stresses. These fndings suggest that JA biosynthesis pathway by regulating the level of JA might control the RSA thus, it may help rice plant in combating macronutrient defciency.