高景輝Kao, Ching–Huei臺灣大學:農藝學研究所郭俊伶Kuo, Chun-LingChun-LingKuo2010-05-052018-07-112010-05-052018-07-112008U0001-2307200815152200http://ntur.lib.ntu.edu.tw//handle/246246/180064本論文係以水稻品種台中在來1號 (Oryza sativa L. cv. Taichung Native 1, TN1) 為材料，探討 (一) 水稻在缺硫與鎘之雙重逆境對鎘毒害之影響與 (二) 水稻幼苗熱休克前處理對鎘逆境所誘導之銨離子累積與 PAL 活性增加之影響。苗在缺硫下生長，至第三片葉片完全展開後進行鎘處理。試驗結果顯示，缺硫處理降低水稻幼苗地上部株高、鮮重和乾重，但不影響根長、根鮮重與根乾重。缺硫處理也降低水稻幼苗葉片蛋白質和葉綠素含量。不論以 3,3''–diamino–benzidine 染色觀察或化學分析都發現，缺硫會導致幼苗葉片與根部 H2O2 累積。但分析水稻幼苗第二片葉片與根中 ABA 含量，發現對照與缺硫處理間沒有顯著差異。缺硫處理亦可降低水稻幼苗含硫化合物，如： non–protein thiols、cysteine (Cys) 與 reduced 型式 glutathione (GSH) 之含量，與降低 ascorbate peroxidase (APX)、glutathione reductase (GR)、catalase (CAT) 之活性，然而缺硫處理增加 superoxide dismutase (SOD) 活性。試驗結果也顯示，缺硫之水稻幼苗會使後續之鎘毒害加重。外加 GSH、Cys 處理可降低缺硫幼苗所表現之鎘毒害。試驗結果似乎說明缺硫之水稻幼苗由於抗氧化物 (cysteine 與 glutathione) 含量與抗氧化酵素 (APX、GR、CAT) 活性之降低，是造成後續鎘毒害加劇的可能原因。逆境會誘導幼苗第二片葉片中 NH4+ 含量與 phenylalanine ammonia–lyase (PAL) 比活性增加，而熱休克前處理 (HS，黑暗下 45℃) 則降低鎘所誘導 NH4+ 含量與 PAL 比活性增加。在 30℃ 黑暗下 (non–HS) 進行 H2O2 (0.5 mM) 與 GSH (1 mM) 前處理亦可降低鎘所誘導 NH4+ 累積與 PAL 比活性之增加。在 HS 狀況下處理 GSH 合成抑制劑 buthionine sulfoxinine 與 NADPH oxidase 合成抑制劑 imidazole 可促進 NH4+ 累積與 PAL 比活性之增加。在 non–HS 狀況下，外加 ascorbate 及其合成前驅物 galactono–1,4–lactone 可降低鎘所誘導 NH4+ 累積與 PAL 比活性之增加。In this thesis, rice (Oryza sativa L. cv. Taichung Native 1, TN1) seedlings were cultivated hydroponically in green house and were used to study Cd toxicity of rice seedlings under sulfur deficienct conditions. Also included this thesis is the effect of heat shock on Cd–induced accumulation of ammonium ion and increase specific activity in leaves of rice seedlings.ength, dry weight and fresh weight of shoot and the contents of chlorophyll and protein content were reduced under sulfur–deficient conditions. Moreover, sulfur–eficient treatment resulted in accumulation of H2O2 in roots and leaves. However, sulfur deficiency had no effect on abscisic acid content. Sulfur containing compounds, such as non–protein thiols, cysteine and glutathione, were reduced in leaves of rice seedlings grown under sulfur–deficient conditions. Sulfur–deficient seedlings had lower activity of APX, GR and CAT, but higher activity of SOD than sulfur-sufficient seedlings. Exogenous application of glutathione, cysteine to sulfur–deficient rice seedlings reduced cadmium toxicity of rice seedlings. Results suggest that decrease in the contents of cysteine and glutathione and activities of APX, GR and CAT is the possible reasons of increase in cadmium toxicity in of rice seedlings under sulfur deficient conditions. d treatment resulted in an accumulation of NH4+ and increase in PAL activity in leaves of rice seedlings. Rice seedlings were pretreated with heat shock (HS, 45℃, dark) at the time when the third leaves were fully expanded and then treated with CdCl2. The results indicated that CdCl2 induced NH4+ accumulation and increased PAL activities in leaves of rice seedlings. HS pretreatment decreased Cd–induced NH4+ accumulation and PAL specific activity. H2O2 (0.5 mM) and GSH (1 mM) pretreatments under non–HS conditions also had the same effects as HS pretreatment. Pretreatments with GSH inhibitor, buthionine sulfoxinine, or NADPH oxidase inhibitor, imidazole, under HS condition resulted in enhancing Cd–induced NH4+ accumulation and PAL specific activity. Under non–HS condition, pretreatments with ascorbate and its precursor galactono–1,4–lactone reduced Cd–induced NH4+ accumulation and decrease PAL specific activity.論文口試委員審定書…………………………………………….…………...…….. i辭………………………………………………………………….…………...…. ii文摘要……………………………………………………………………….…....iv文摘要……………………………………………………….……………….…...vi錄………………………………………………………………….…………......viii目錄………………………………………………………………........................ ix目錄……………………………………………………………….………...….…xi寫字對照……………………………………………………….….………...…...xii言……………………………………………………………….…..……………....1、鎘危害……………………………………………………………..…………..4、鎘對植物體之生理影響及病徵………………………………….…...............5、鎘與活化氧族的生成…………………………………………..……………...5、鎘與植物的抗氧化系統………………………………….……………………6、硫的重要性……………………………………………….…....…...............…8、綜合逆境…………………………………………………...….…………….…9、PAL 與 NH4+ 與逆境關係……………………………………….…………10、熱休克反應與逆境抵禦………………………………………………..….....10、論文研究方向………………………………………………….………...…..11料方法………………………………………….…………………………………12、材料種植、處理與採收方式………………………………………….….…12、水稻幼苗生長之分析…………………………………………………..……14、化學成分分析……………………………………….…………………..…...14、酵素活性分析…………………………………………………….……….…21、供試藥劑原液之配置……………………………………………..…….…...24、數據統計分析…………………………………………………….……..…...24果………………………………………………………………...………………..25 論………………………………………………………………………….....……45考文獻…………………………………………………………………………….50application/pdf1465889 bytesapplication/pdfen-US水稻鎘缺硫熱休克銨離子ricecadmiumsulfur deficiencyheat shockNH4+thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/180064/1/ntu-97-R95621111-1.pdf