Determination of Abscisic Acid and its Relationship to Drought Stress Based on Cowpea Varieties with Different Capability of Drought Resistance

Cowpea (Vigna unguiculata L.) is one of the most important grain legume supplying necessarily dietary proteins. Although its can tolerate drought environment, still the severe condition can limit the growth and development of this plant. Abscisic acid (ABA) has a crucial function in stress physiology, but little information is available for methods describing ABA determination in cowpea and its relationship to drought stress based on cowpea varieties with different capability of drought resistance. Here, an effectual approach based on high-performance liquid chromatography (HPLC) method was established to separate and determine the endogenous abscisic acid in cowpea and further the cowpea varieties with different capability of drought resistance were used to explore relationships between ABA content and drought stress. The results potentially provided useful reference for the cultivation of cowpea crop. Results-This method showed good liner regression (R² = 0.9998), coupled with high stability, precision and repeatability. The endogenous ABA decreased under drought treatment and the drought sensitive line had higher ABA content than drought resistant one, suggesting ABA performs a vital function in cowpea’s response and resistance to drought stress. The studies potentially provided useful reference for the cultivation and breeding of cowpea crop.