低溫逆境對綠豆白化幼苗之生長、粒線體活性及其蛋白質合成之影響

Chilling Stress Effects on the Growth, Mitochondrial Activity and Protein Synthesis in Etiolated Mung bean Seedlings

本研究以對低溫敏感的植物──綠豆（Vigna radiata L.）為材料。在黑暗中萌芽32小時的綠豆幼苗，經4°C處理不同時間後，分析其生長、粒線體活性及蛋白質合成能力等；其結果顯示下列各種現象皆受到抑制：(一)幼苗的生長，(二)粒線體的succinate dehydrogenease活性；(三)幼苗的蛋白質合成能力。但低溫處理會導致幼苗在室溫下呼吸速率增快，且幼苗的組織也受到傷害，因此組織內溶質的漏出物增加。在4°C低溫處理下所合成的35S-蛋白質，經SDS-膠體電泳分析及fluorography後，其中有13種蛋白質帶（protein band）是低溫誘導出的蛋白質（chilling induced proteins）；其分子量是110，88，78，69，58，48，38，27，22，19，14，12.5 及10.5 KD，其中88，69，58，48，38，14，12.5及10.5 KD是主要的低溫誘導蛋白質。這些蛋白質完全與綠豆的熱休克蛋白質不同。

Mungbean (Vigna radiata L.), a chilling sensitive plant species, was used in this study. Seeds were germinated at 28°C in the dark for 32 h before cold treatment. The seedlings were chilled at 4°C for various durations. Growth, respiration rate, protein synthetic activity, cellular leakages and succinate dehydrogenase activity in isolated mitochondria were then determined. Chilling at 4°C suppressed seedling growth, increased solute leakages, suppressed succinate dehydrogenase activity in isolated mitochondria, inhibited general protein synthesis and induced the synthesis of a set of proteins termed chilling-induced proteins. The molecular weights of these chilling-induced proteins were 110, 88, 78, 69, 58, 48, 38, 27, 22, 19, 14, 12.5 and 10.5 Kd, respectively and the proteins with molecular weights of 88, 69, 58, 48, 38, 14, 12.5 and 10.5 Kd were the major chilling-induced proteins of mungbean seedlings. These chilling-induced proteins were different from the heat shock proteins of mungbean seedlings.