Effect Of Exogenous Abscisic Acid And Its Inhibitors In Tea Plant Chilling Resistance Under Chilling Stress

Tea[Camellia sinensis(L.)O.Kuntze]is one kinds of important economic crop in China.Chilling stress is an important abiotic stress affecting yield and quality of tea products.Abscisic acid(ABA)is an important phytohormone which is responsible for activating chilling resistance.Understanding of ABA effects on tea plant under chilling stress is essential for developing chilling-tolerant tea genotypes.The fresh leaves of Longjing 43 was used as materials,then dealt with 6 kinds of treatment:CK(distilled water);ABA(50 mg/L);Sodium Tungstate Dihydrate(20 mmol/L);ABA and Sodium Tungstate Dihydrate(first ABA,then Sodium Tungstate Dihydrate;Sodium Tungstate Dihydrate and then ABA).After treated 0,4,8,12,24,48 and72 hours,the samples were taken to test relevant indicators.The results as follow:(1)Physiological and biochemical effect of ABA and its inhibitors in tea plant under chilling stress.With the extension of low chilling stress,the contents of proline,soluble sugar and soluble protein increased.After treated with ABA,the contents of proline,soluble sugar and soluble protein significantly improved,compared to the control group.After treated with sodium tungstate,the contents of proline,soluble sugar and soluble protein increased rapidly.After treated with ABA and sodium tungstate,the contents of proline,soluble sugar and soluble protein were slightly lower than the corresponding control group.Chlorophyll content under different reagents at any point of time was not significantly different.(2)Effect of ABA and its inhibitors in tea plant antioxidant enzyme system under chilling stress.The activities of antioxidant enzymes increased under cold stress.After treated with ABA,the activities of antioxidant enzymes were significantly improved under chilling stress.After applying sodium tungstate,the activities of antioxidant enzymes have also been enhanced,but lower than spraying exogenous ABA group.ABA co-spraying with sodium tungstate,the enhance effect of ABA was impaired by sodium tungstate.Our study showed that exogenous ABA can improve chilling resistance ability of tea,sodium tungstate can reduce chilling resistance of tea;common spraying ABA and sodium tungstate and the effect of sodium tungstate will weaken the effect of ABA.