- 作者: 陳浩仁; 蘇仲卿; 宋賢一
- 作者服務機構: 國立台灣大學農業化學研究所
- 中文摘要: 將得自日本九州大學農學部的金南風水稻(Kinmaze)穀粒正常種及其胚乳突變種三株(shrunken二株、sugary一株)培植於人工氣候室,突變種也可得結實穀粒但其產量不高。栽培的水稻在開花後不同生長期採收穀粒樣品,分別測定其中酒精可溶糖(ASS)、水溶性多醣(WSP)及澱粉三部份含量的變化與結構的探討。突變種(尤其是sugary)ASS部分有許多未明之寡醣,其中之一可能是三醣類棉子糖(raffinose)。sugary另含有相當高量的WSP,這些WSP是由葡萄糖所構成之聚合物,可能是短分歧鏈的枝鏈澱粉(short-branched amylopectin)。正常種含有較高量的搬粉,和突變種比較,澱粉的組成與結構只有少許差異。由這等結果推測,shrunken與sugary的突變都降低澱粉生合成前體的供應量,而su-gary除此之外亦對澱粉的合成發生干擾。單一變異導致sugary兩種形質的改變,可能是對兩種調控序列有作用的一種trans調控因子的基因發生變異所致。
- 英文摘要: A Japanese rice cultivar, Kinmaze, and three of its endosperm mutants were cultivated in a phy-totron. The grain yields of mutants were low. Grains were sampled at different stages after flowering,and their carbohydrates were fractionated according to solubilities into alcohol soluble sugar (ASS), watersoluble polysaccharide (WSP) and starch fractions. Quantitative and qualitative analyses indicated thatthe mutant grains, especially the sugary phenotype, contained much of several oligosaccharides in the ASSfraction. One of them could be the trisaccharide raffinose. In addition, the sugary grains contained alarge excess amount of WSP, which was characterized as an amylopectin with short branch chains. Thestarch content was much higher in the normal grains than in any of the mutants. However, no significantdifferences were found with respect to the composition and structure of the starch samples based on theresults of debranching analysis. Based on these findings, both the sugary and shrunken mutants werecharacterized as having a reduced supply of starch precursor, the latter in addition having a disturbed modeof starch synthesis. The one point mutation which affected two sites of the metabolism in the sugary mutantwas attributed to the alteration of a double-targeting trans acting element.
- 中文關鍵字: rice; endosperm mutants; carbohydrate constituents; trans acting element.
- 英文關鍵字: --