INDUCTION OF CRASSULACEAN ACID METABOLISM IN THE FACULTATIVE HALOPHYTE MESEMBRYANTHEMUM-CRYSTALLINUM BY ABSCISIC-ACID
INDUCTION OF CRASSULACEAN ACID METABOLISM IN THE FACULTATIVE HALOPHYTE MESEMBRYANTHEMUM-CRYSTALLINUM BY ABSCISIC-ACID
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DOI：
10.1104/pp.93.3.1253
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发表时间：
1990-07-01
期刊：
影响因子：
7.4
通讯作者：
EDWARDS, GE
中科院分区：
文献类型：
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作者：
CHU, C;DAI, ZY;EDWARDS, GE
兼性盐生植物中胚藻的碳同化方式从C3途径转变为景天酸代谢(CAM)，以响应水分胁迫。在本研究中，外源抗坏血酸(ABA)在微摩尔浓度下，可以部分替代水分胁迫诱导该物种的CAM。当ABA浓度为5-10微摩尔时，水培叶片、根或土壤中的ABA在数天内诱导CAM的表达(由夜间可滴定总酸度和苹果酸的积累表明)。施加ABA后，磷酸烯醇式丙酮酸羧化酶和NADP-苹果酸酶的活性也增加。ABA诱导的程度和时间进程与盐和水分胁迫的诱导程度和时间进程相当。叶片可溶性蛋白的电泳分析表明，在ABA、盐和水分胁迫诱导过程中，磷酸烯醇式丙酮酸羧化酶活性的增加是由于酶蛋白的数量增加所致。ABA可能是胁迫诱导结晶藻CAM表达的一个因子，在胁迫和生化适应之间起着功能纽带的作用。
The facultative halophyte, Mesembryanthemum crystallinum, shifts its mode of carbon assimilation from the C3 pathway to Crassulacean acid metabolism (CAM) in response to water stress. In this study, exogenously applied abscistic (ABA), at micromolar concentrations, could partially substitute for water stress in induction of CAM in this species. ABA at concentrations of 5 to 10 micromolar, when applied to leaves or to the roots in hydroponic culture or in soil, induced the expression of CAM within days (as indicated by the nocturnal accumulation of total titratable acidity and malate). After applying ABA there was also an increase in phosphoenolpyruvative carboxylase and NADP-malic enzyme activities. The degree and time course of induction by ABA were comparable to those induced by salt and water stress. Electrophoretic analyses of leaf soluble protein indicate that the increase in phosphoenolpyruvative carboxylase activity during the induction by ABA, salt, and water stress are due to an increase in the quantity of the enzyme protein. ABA may be a factor in the stress-induced expression of CAM in M. crystallinum, serving as a functional link between stress and biochemical adaptation.