氯化鋁對水稻幼苗根生理作用影響之研究

Studies on the Physiological Effects of AlCl3 on Roots of Rice Seedlings

王振武(Jen-Wu Wang)

指導教授 ： 高景輝

國立臺灣大學/生物資源暨農學院/農藝學研究所/博士(2006年)

https://doi.org/10.6342/NTU.2006.01052

摘要

第二章中文摘要
在本試驗中我們探討氯化鋁對水稻完整穀粒及去殼穀粒中貯存物質的影響。氯化鋁對發芽中水稻穀粒的乾重、鮮重、澱粉以及蛋白質含量沒有影響，對於α-amylase 及protease 活性亦無影響。但去除穀殼的穀粒以氯化鋁處理，則發現氯化鋁會抑制胚乳乾重、鮮重、澱粉以及蛋白質含量的下降，以及抑制胚乳中α-amylase 及 protease活性的上升。試驗證實上述結果是由於水稻穀粒的穀殼會阻礙鋁進入水稻穀粒胚乳中。

第三章中文摘要
將氯化鋁溶解於半量之木村氏B水耕液，其抑制水稻根生長之能力會明顯低於溶解於蒸餾水中的氯化鋁。木村氏B水耕液內含有無機鹽與有機酸，因此我們探討氯化鈣、氯化鎂與有機酸對氯化鋁所抑制水稻幼苗根生長之影響。試驗結果顯示，氯化鈣、氯化鎂、磷酸氫鈉等無機鹽及citrate，malate，tartarate與oxalate等有機酸可降低氯化鋁所抑制水稻根之生長。進一步研究發現氯化鈣、氯化鎂磷酸氫鈉等無機鹽及citrate，malate，tartarate與oxalate等有機酸係經由降低水稻根內鋁之含量而降低氯化鋁對水稻幼苗根生長的抑制作用。

第四章中文摘要
本章主要探討氯化鋁對水稻幼苗根抗氧化系統的影響，以及在氯化鋁抑制水稻幼苗根生長的過程中，抗氧化劑AsA及GSH所扮演的角色。氯化鋁處理會迅速的抑制水稻幼苗根的生長，但不會影響脂質過氧化作用及抗氧化酵素的活性。相較於對照組，氯化鋁處理會導致H2O2、AsA及GSH含量的下降，而外加AsA或GSH則會減緩氯化鋁對水稻幼苗根生長的抑制作用。氯化鋁處理會造成水稻幼苗根內SPOX活性的上升以及木質素含量的累積，而外加AsA或GSH則會減緩氯化鋁處理所導致H2O2、SPOX活性及木質素含量的增加，試驗結果顯示氯化鋁處理導致AsA及GSH含量的下降，因而誘導木質化的發生，可能是鋁抑制水稻幼苗根生長的機制之一。

第五章中文摘要
本章主要是探討氯化鋁所抑制的水稻幼苗根生長是否與多元胺有關。研究結果顯示氯化鋁抑制水稻幼苗根生長的同時，造成putrescine (PUT) 含量的上升，卻降低spermidine (SPD) 及spermine (SPM) 的含量。利用PUT合成抑制劑D-arginine (D-Arg) 及methylornithine (MO) 處理，則明顯降低氯化鋁所導致PUT含量的上升。氯化鋁處理也會導致水稻幼苗根內diamine oxidase (DAO) 活性下降。外加D-Arg及MO處理則可以部分恢復氯化鋁所抑制的水稻幼苗根生長，而其機制並非透過降低鋁的吸收，若再處理PUT則無法觀察到D-Arg及MO對氯化鋁抑制水稻幼苗根生長的恢復作用。本研究顯示PUT的累積是氯化鋁抑制水稻幼苗根生長的原因之一，而木質化則是PUT或氯化鋁抑制水稻幼苗根生長的可能機制。

關鍵字

水稻 ； 氯化鋁 ； 生長 ； 水解酵素 ； 有機酸 ； 氧化逆境 ； 抗敗血酸 ； 多元胺 ； 木質素

並列摘要

Chapter 2
The effect of AlCl3 on endosperm reserve mobilization of rice grains or dehulled rice grains during germination was investigated. AlCl3 had no effect on grain dry weight (DW), grain fresh weight (FW), protein and starch contents in endosperm, α-amylase and protease activities in endosperm of germinating rice grains. However, when dehulled rice grains were treated with AlCl3, AlCl3 inhibited the decrease in DW, FW, and starch and protein contents, and the increase in α-amylase and protease activities in endosperm. Evidence is provided to show that the hull is a barrier against influx of Al to endosperm.

Chapter 3
AlCl3 dissolved in half-strength Kimura B nutrient solution was observed to be less effective in inhibiting root growth of rice seedlings than that dissolved in distilled water. Kimura B nutrient solution is composed of inorganic salts and citrate. Thus, we investigated the influence of inorganic salts and organic acids on AlCl3-inhibited root growth of rice seedlings. It was observed that CaCl2, MgCl2, NaH2PO4, citrate, malate, tartarate, and oxalate were able to reduce AlCl3-inhibited root growth of rice seedlings. The effect of CaCl2, MgCl2, and organic acids on AlCl3-inhibited root growth is mediated through reducing Al level in roots of rice seedlings.

Chapter 4
The effect of AlCl3 on the antioxidant system of rice roots and the role of antioxidants AsA and GSH in AlCl3-inhibited growth of rice roots were investigated. AlCl3 treatment resulted in a rapid inhibition of root growth but had no effect on lipid peroxidation and antioxidative enzyme activities in rice roots. AlCl3 treatment resulted in lower content of H2O2, AsA, and GSH than controls. Exogenous AsA or GSH conteracted growth inhibition by AlCl3. AlCl3 treatment increased syringaldazine peroxidase (SPOX) activities and lignin content in rice roots. Exogenous AsA or GSH prevented the decrease in H2O2 content and the increase in SPOX activities and lignin content in rice roots caused by AlCl3. Results suggest that lignification induced by low AsA or GSH content may explain the mechanism of Al-inhibited growth of rice roots.

Chapter 5
The effects of AlCl3 on growth and polyamine levels of rice roots were investigated. When rice roots were treated with AlCl3, root growth was markedly inhibited. AlCl3 treatment resulted in a higher putrescine content and lower spermidine and spermine contents in rice roots. D-Arginine and a-methylornithine, inhibitors of putrescine biosynthesis, caused a reduced content of putrescine in rice roots under Al stress. AlCl3 treatment also resulted in a decrease in diamine oxidase activity in rice roots. The growth of rice roots in the presence of AlCl3 was recovered after the addition of D-arginine or a-methylornithine. The protective effect of D-arginine or a-methylornithine in counteracting AlCl3-inhibited growth of rice roots is unlikely caused by reduction of Al uptake. Furthermore, the effect of the growth recovery in AlCl3-treated rice roots by D-arginine or a-methylornithine was reversed by the addition of putrescine. Our results strongly suggest that putrescine accumulation is a factor causing growth inhibition of rice roots under Al tress. Evidence is also presented to show that lignification is responsible for putrescine- and AlCl3-inhibited growth of rice roots.

並列關鍵字

rice ； AlCl3 ； growth ； hydrolytic enzymes ； organic acids ； oxidative stress ； ascorbic acid ； polyamines ； lignin

參考文獻

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