为探讨外源脱落酸(ABA)及其抑制剂钨酸钠对茶树[ Camellia sinensis ( Linn.) O. Ktze.]耐寒性的影响效应，以茶树品种‘龙井 43’(‘Longjing 43’)的 2 年生幼苗为实验材料，在低温(4℃ )条件下分别设置 50 mg· L^-1 ABA和 20 mmol· L^-1钨酸钠单一及复合处理共 6 个处理组( T1:仅喷施蒸馏水，对照;T2:仅喷施 ABA；T3：仅喷施钨酸钠；T4：同时喷施 ABA 和钨酸钠; T5:0 h 时喷施 ABA，24 h 时喷施钨酸钠；T6:0 h 时喷施钨酸钠， 24 h 时喷施ABA)，对处理 0 ~ 72 h 叶片中渗透调节物质含量和抗氧化酶活性的变化进行了比较分析。 结果显示:低温条件下，各处理组幼苗叶片中可溶性糖、游离脯氨酸和可溶性蛋白质含量以及超氧化物歧化酶( SOD)、过氧化氢酶( CAT)和过氧化物酶(POD)活性均在处理初期逐渐升高，之后各指标的变化趋势存在差异。 在处理的中后期，除 T4 处理组的游离脯氨酸含量低于对照组外，各处理组的可溶性糖、游离脯氨酸和可溶性蛋白质含量总体上显著高于对照组；T2 处理组的 SOD、CAT 和 POD 活性均显著高于对照组，而 T3 处理组仅 SOD 活性明显高于对照组，其 CAT 和POD 活性则低于或略高于对照组。 对各单一与复合处理组的比较结果显示:T4 处理组的 SOD 和 POD 活性总体上低于 T2 处理组，但高于 T3 处理组;而其 CAT 活性总体上低于 T2 和 T3 处理组。 在处理 24 h 后，T5 处理组的可溶性糖、游离脯氨酸和可溶性蛋白质含量以及 SOD 和 POD 活性的变化趋势与 T2 处理组一致;T6 处理组的可溶性糖和游离脯氨酸含量及 POD 活性变化趋势与 T3 处理组一致，而其可溶性蛋白质含量以及 SOD 和 CAT 活性的变化趋势却与 T3 处理组有一定差异。上述研究结果表明:低温条件下喷施适量的 ABA 或钨酸钠均可以提升茶树叶片中渗透调节物质含量及抗氧化酶活性，但同时喷施 ABA 和钨酸钠对茶树叶片中渗透调节物质含量及抗氧化酶活性的影响却不显著。

In order to study effects of exogenous abscisic acid (ABA) and its inhibitor sodium tungstate
on cold tolerance of Camellia sinensis ( Linn.) O. Ktze., taking two-year-old seedling of C. sinensis‘Longjing 43’ as experimental material, six treatment groups of single and mixed treatments of 50mg· L^-1 ABA and 20 mmol· L^-1 sodium tungstate (T1: only spraying distilled water, the control; T2:only spraying ABA; T3: only spraying sodium tungstate; T4: spraying ABA and sodium tungstate at the same time; T5: spraying ABA at 0 h, and spraying sodium tungstate at 24 h; T6: spraying sodium tungstate at 0 h, and spraying ABA at 24 h) were set up under low temperature (4 ℃), changes in osmoregulation substance content and antioxidant enzyme activity in leaf treating for 0 - 72 h were compared and analyzed. The results show that contents of soluble sugar, free proline and soluble protein and activities of superoxide dismutase ( SOD), catalase ( CAT ) and peroxidase ( POD ) in leaf of seedling in each treatment group increase gradually at the early stage of treatment, and afterwards, changing trends of each index are different. At the middle and later stages of treatment, except free proline content in T4 treatment group is lower than that in the control group, contents of soluble sugar, free proline and soluble protein in each treatment group are generally significantly higher than those in the control group; activities of SOD, CAT and POD in T2 treatment group are significantly higher than those in the control group, while in T3 treatment group, only SOD activity is obviously higher than that in the control group, and activities of CAT and POD are lower or slightly higher than those in the control group. The results of comparison on single and mixed treatment groups show that activities of SOD and POD in T4 treatment group are generally lower than those in T2 treatment group, but are higher than those in T3 treatment group, while its CAT activity is generally lower than that in T2 and T3 treatment groups. After treated for 24 h, changing trends of contents of soluble sugar, free proline and soluble protein and activities of SOD and POD in T5 treatment group are consistent with those in T2 treatment group; changing trends of contents of soluble sugar and free proline and POD activity in T6 treatment group are consistent with those in T3 treatment group, but there are a certain differences in changing trends of soluble protein content and activities of SOD and CAT between T6 treatment group and T3 treatment group. It is suggested that spraying proper amount of ABA or sodium tungstate can enhance osmoregulation substance content and antioxidant enzyme activity in leaf of C. sinensis under low temperature, but effect of spraying ABA and sodium tungstate at the same time on osmoregulation substance content and antioxidant enzyme activity in leaf of C. sinensis is not significant.