水稻懸浮細胞對逆境之反應

Abstract

本研究是以逆境處理來採討水稻細胞在逆境下的生長及生理反應。 逆境處理包括在培養基中添加20mM NaCl 1. 63Μm H2 O2及真菌抽出物，也使用去除含磷成份之培養基。逆境處理都普遍會抑制細胞生長並降低細胞內可溶性蛋白質含量，但在影響程度上有差別。從蛋白質的電冰分析，可以觀察到在缺磷條件下 雖然蛋白質總量大幅降低，仍有新的蛋白質(26 Kd) 的出現，而且分子量59 Kd蛋白質合量也會增高，甚至釋出細胞外的35 Kd蛋白質也有明顯增加。鹽逆境下細胞的生長並無明顯受到抑制，但促使細胞內超氧歧化酶 觸媒酶 過氧化氫酶活性的增高，並促進酸性磷酸酶的分泌。真茵抽出物也一樣能促使超氧歧化酶及過氧化氫酶活性增高，但不影響酸性磷酸酶活性。缺磷逆境下細胞生長受到抑制，細胞內可溶性蛋白質也明顯降低，然而酸性磷酸酶活性無論是細胞外或細胞內卻大幅增高;從異構酶分析中發現有新異構酶的出現，然而反映酶活性的增高應是細胞內的API及細胞外的AP01異構酶。這些結果顯示細胞會藉生理代謝的改變來適應不同逆境，以求取生存。

Cell growth and physiological responses of rice suspension cells (Oryza sativa cv. Tainan 5) in the phosphorous deficient medium or exposed to 20 mM NaCl, 1.63 μM Hydrogen peroxide or fungal elicitor were investigated.' Cell growth and soluble protein content in cell were inhibited under the stresses. Changes of soluble protein pattern in the media and the cell extract were analyzed by SDS-PAGE. A 59 Kd protein was increased and a 26 Kd protein was induced with phosphate deficient treatment. 26 Kd protein seems to be a specific protein appeared only with phosphate deficiency. The results were further confrrmed with transferred experiments. CcF growth was not obviously affected with salt treatment, \\'hile the activity increase of superoxide dismut~<;(catalase and peroxidase in cells as well as extracellular acid phosphatase were observed. Although serious inhibition of both cell growth and protein synthesis were shown under the stress of phosphorous d. ,L., "'oj. activities of intra- and extracellular acid phosphatase increased with the time of stress treatment. !soZY'lie ;'attems of acid phosphatase in cells were changed with the stress treatment, but the main isozymes AP I and APO1 should be responsible for the activity increase. The results indicate that stress could affect the cells to ',enninate some proteins to be synthesized and to synthesize certain new proteins simultaneously. For adaplpt; >j] to the stressful environment cells should inevitably adjust the metabolism of itself in order to survive.