中文摘要 |
本研究探討相思樹(Acacia confusa)苗木在模擬酸雨逆境下的生長和生理活性表現,並比較外源添加鈣苗木抵抗酸雨之反應。相思樹苗木先預處理不同濃度(0 mM、0.15 mM、10 mM)的 CaCl2,再噴灑以SO4 2-:NO3-當量濃度比2.5:1混合後並用蒸餾水調至 pH 3.0 的模擬酸雨,且以蒸餾水(pH 5.6)作為對照組,於酸雨噴灑2週後進行取樣分析。經過酸雨處理後,苗木的過氧化酵素(peroxidase, POD)活性顯著上升,而抗壞血酸過氧化酵素(ascorbate peroxidase, APx)活性則顯著降低,使得膜脂質過氧化程度顯著提高,葉綠素螢光參數 Fv/ Fm 值顯著降低,造成細胞膜滲漏率提高。經由 0.15 mM CaCl2 預處理則能幫助苗木抵抗酸雨逆境,苗木的 APx 活性相較於酸雨處理組顯著上升,使得膜脂質過氧化程度明顯降低,而葉綠素螢光參數 Fv/Fm 值顯著提高,導致細胞膜滲漏率降低。然而,處理高濃度的 CaCl2 (10 mM),反而使得苗木在酸雨逆境下,其細胞膜脂質過氧化程度和細胞膜滲漏率相對提高,而抗氧化酵素 APx 活性和葉綠素螢光參數 Fv/Fm 值顯著低於 0.15 mM CaCl2 處理者。
The study was to examine the effects of simulated acid rain on growth and physiological performance of Acacia confusa seedlings, and to compare with the responses of seedling to exogenous calcium before simulated acid rain treatment. Seedlings were pretreated with different concentrations of CaCl2 (0 mM, 0.15 mM, 10 mM, respectively), and then were sparyed with simulated acid rain, which was a mixture solution of 2.5:1 equivalent concentration ratio of SO4 2 – : NO3 – and was adjusted to pH 3 with distilled water, and distilled water (pH 5.6) as control treatment. After 2 weeks, The leaves of seedlings developed a distinct calcium deficiency symptoms under simulated acid rain treatment, peroxidase (POD) activity increased but ascorbate peroxidase (APx) activity decreased, resulted in membrane lipid peroxidation increased. Additionally, chlorophyll fluorescence parameter (Fv/Fm) decreased significantly under simulated acid rain treatment, resulted in membrane leakage increased. Application of 0.15 mM CaCl2 solution to seedlings, APx activity increased but membrane lipid peroxidation decreased, resulted in membrane leakage decreased. The Fv/Fm of seedlings also increased. Furthermore, application of 10 mM CaCl2 solution, resulted in APx activity decreased as well as membrane lipid peroxidation increased. Additionally, Fv/Fm reduced and membrane leakage increased compared to 0.15 mM CaCl2 solution treatment under simulated acid rain stress. |