摘要
在我国普遍种植的黑麦（冬牧70），在铝胁迫下其根系能分泌柠檬酸苹果酸复合有机酸。为了揭示在铝胁迫下黑麦根系分泌的复合有机酸（柠檬酸-苹果酸）的解毒机理，研究了上述复合有机酸对铝胁迫下小麦幼根细胞膜透性、过氧化物酶（POD）、过氧化氢酶（CAT）、H^＋-ATPase活性和根伸长的影响。结果显示．复合有机酸使小麦幼根电解质渗漏率下降，根尖过氧化物酶、过氧化氧酶、H^＋-ATPase活性提高，幼根伸长量增加，并且复合有机酸的效果随其浓度（25～200μmol／L）的增加而增强。在50或100μmol／L苹果酸的基础上，柠檬酸与苹果酸比值（C：M）从1：2增加到1：1，复合有机酸的解毒效果更显著；而在相同柠檬酸浓度下，苹果酸浓度增加一倍对小麦铝毒害无显著影响。可以推断，在铝胁迫环境下，黑麦根系分泌的柠檬酸-苹果酸复合有机酸可以维持细胞膜结构的完整性，减轻自由基伤害和铝对根生长的毒害，并且复合有机酸中柠檬酸的作用强于苹果酸。铝胁迫下根系分泌复合有机酸是黑麦抵御铝毒害的有效机制。
Aluminum （Al） induced secretion of both （Dongmu 70）, which is planted widely in China. In order to compound organic acids （citrate and malate） in rye, the citrate and elucidate Al malate from detoxification effects of these organic roots of rye mechanism of acids on root elongation, root cell membrane osmosis, activities of catalase （CAT）, peroxidase （POD） and H^＋- ATPase of rootapices in Al-sensitive wheat seedlings were studied. The result showed that electrolyte of roots induced by Al was suppressed by addition of both citrate and malate, while an increase in root elongation and activates of CAT, POD, H^＋-ATPase were found in the treatments with both citrate and malate under Al stress. These effects of compound organic acids were increased with the increasing of their dose（25-200 μmol/L）. An increasing rate of citrate/malate（from 1 ： 2 to 1 ：1） could depressed Al toxicity more significantly in certain concentra These results indicated that secretion of both citrate and malate tion of malate（50,100 μmol/L）. under Al stress was an effective mechanism for rye （Dongmu 70） to deal with Al toxicity to enhance root growth and cell membrane structure integrality, and decrease free radical damage.
出处
《广西农业生物科学》
CAS
CSCD
2006年第4期325-329,340,共6页
Journal of Guangxi Agricultural and Biological Science
基金
国家自然科学基金项目(30360048)
教育部优秀青年教师计划项目(2003[355])
关键词
黑麦
有机酸
铝
小麦
ryc
organic acid
aluminum
wheat
