摘要
对番茄和羽扇豆在不同磷浓度水培中的应答机制作了系统分析 .结果表明 ,在低磷条件下羽扇豆和番茄根系有机酸、酸性磷酸酶和植酸酶分泌量均有所增加 .但下列表现差异明显 :①羽扇豆根系酸性磷酸酶分泌量明显高于番茄 ,而植酸酶分泌量则趋势相反 .②羽扇豆根系有机酸的分泌增高量显著高于番茄 .③番茄诱发应答反应的介质磷浓度显著比羽扇豆高 (前者约为 30 0 μmol/L ,而后者为 10 μmol/L)④番茄诱导应答反应时的内部磷含量(PTPC)亦比羽扇豆高 (前者为 4.2mgP·g-1,后者为 1.5mgP·g-1) .以上结果显示 ,在正常生长过程中番茄对磷的需求量明显高于羽扇豆 ,可能是导致其对磷缺乏适应能力低下的重要因素 .同时缺磷条件下根系诱导分泌酸性磷酸酶、植酸酶和有机酸可能是植物获取磷酸盐 。
Responses of aquicultured lupin and tomato plants to low phosphorus(P) concentrations in the growth media were compared. Under the low P condition, the lupin and tomato plants exhibited similar responses though the rates of the responses were different. These responses included an increased secretion of organic acids, Apase and phytase by roots. However, the following differences were apparent. (1) The increase of Apase secretion was higher in lupin roots than in tomato roots while the increase of phytase secretion was reverse. (2) The increase of organic acid secretion was considerably higher in lupin than that in tomato. (3) The external threshold P concentration in growth media to induce the responses was considerably lower in lupin (approximately 10 μmol/L) than in tomato (300 μmol/L P). (4) The physiological threshold P content (PTPC), an internal P content to induce the response, was considerably higher in tomato (4.2 mg P·g -1) than in lupin (1.5 mg P·g -1), indicating that the P requirement of tomato for normal growth was quite higher than that of lupin plant. It was considered that the high P requirement of tomato for normal growth was the most important factor in the low adaptive ability to P deficient conditions. The secretion of Apase, phytase and organic acids by roots provides a set of adaptive mechanisms by which plants can enhance the availability of P and therefore alter the nutrient status in the rhizosphere.
出处
《南开大学学报（自然科学版）》
CAS
CSCD
北大核心
2001年第4期91-97,122,共8页
Acta Scientiarum Naturalium Universitatis Nankaiensis
基金
NaturalScienceFoundationofTianjin(99312 2 5 11 4)
