Coronatine effects on yield, nutrient uptake, and physio-biochemical attributes of soybean roots

Roots absorb water and nutrients from the soil, give mechanical support to plants, and supply hormones that affect many physiological and biochemical processes. Roots also exert control over whole-plant growth and development by synthesizing plant hormones and controlling the uptake of mineral nutrients. Coronatine (COR) is an analogue of jasmonic acid and is a chlorosis-inducing non-hostspecific phytotoxin with an alleviative effect on plant growth under stress conditions. A 2-year field study was conducted to determine the effect of COR on the physiological and biochemical attributes of the root and the seed yield of soybean (Glycine max L. Cv. Zhonghuang 13). COR was foliar-applied at 10nM during the 7-trifoliolate leafs stage. Root dry weight was significantly increased on average by 37% with COR over the 2years. The root nitrogen concentration increased by 19.2%, phosphorus concentration by 23.3%, and potassium concentration by 31.2% following COR application. The content of cytokinins was increased by 31.5% and 46.0%, while that of abscisic acid was decreased by 45.0% and 25.5% with COR over the 2years. Seed yield was increased 7.0% in 2008 and 9.6% in 2009, respectively, due to COR application.