本研究探討巴克素(Paclobutrazol, PBZ)前處理對淹水逆境甘藷之抗氧化酵素與抗氧化物的影響。甘藷品種臺農57號栽種於網室內之塑膠盆，維持適當水分45天後，以PBZ（0及0.5mg/plant）處理1天，接著淹水至土表上5cm至5天，而後排水2天，以多因子設計逢機完全區集3重複，每植株採完全展開之幼葉，測定抗氧化酵素活性與抗氧化物含量。結果顯示，經過不同天數淹水，增加的抗壞血酸過氧化酶活性、以及總穀胱甘肽、氧化態抗壞血酸與總抗壞血酸之含量提供甘藷較高之淹水耐受性。甘藷在無淹水狀態下，穀胱甘肽還原酶與抗壞血酸過氧化酶之活性以及總穀胱甘肽、氧化態抗壞血酸與丙二醛之含量受PBZ前處理之調節而增加，PBZ可能促進甘藷維持活化氧族生成與解毒間平衡的能力。甘藷對淹水逆境具保護機制，PBZ前處理使此潛力表現，PBZ前處理增加甘藷不同淹水時間與排水後所有抗氧化酵素活性與抗氧化物含量，提高甘藷之淹水耐受性，尤其是丙二醛含量受高度調節。
The aim of this research was to study the effect of paclobutrazol pretreatment on the changes of antioxidative enzymes and antioxidants in the flooding-stressed sweetpotato Ipomoea batatas (L.) Lam. 'Tainung 57' was grown in plastic boxes in a screenhouse and maintained in optimal water conditions for 45 days followed by PBZ treatments (0 and 0.5 mg/plant) for 1 day. Then flooding was induced by raising the water level to 5 cm above the soil medium surface for a 5-day period followed by drainage for 2 days. A factorial experiment in randomized complete blocks with three replications was conducted. Young fully expanded leaves from each plant were clipped to measure enzyme activities and antioxidant contents. Increased ascorbate peroxidase activity, total glutathione, oxidized ascorbic acid, and total ascorbic acid amounts on different days of flooding provided the sweetpotato with increased flooding tolerance. The levels of glutathione reductase, ascorbate peroxidase, total glutathione, oxidized ascorbic acid, and malondialdehyde were regulated and elevated by paclobutrazol pretreatment under non-flooded conditions. Paclobutrazol pretreatment increased the levels of all antioxidative enzymes and antioxidants following different flooding durations and drainage, and boosted the flooding tolerance of the sweetpotato.
