EVALUATION OF WATER STRESS CONTROL WITH POLYETHYLENE GLYCOLS BY ANALYSIS OF GUTTATION
EVALUATION OF WATER STRESS CONTROL WITH POLYETHYLENE GLYCOLS BY ANALYSIS OF GUTTATION
复制标题
DOI：
10.1104/pp.47.4.453
复制
发表时间：
1971-01-01
期刊：
影响因子：
7.4
通讯作者：
ECKARD, AN
中科院分区：
文献类型：
--
作者：
KAUFMANN, MR;ECKARD, AN
辣椒(Capsicum FrutescensL.)在利于抽穗的条件下，研究了聚乙二醇对植物水分胁迫的控制效果。在营养液中加入聚乙二醇6000，在相同的水势下，土壤中的水分关系与预期的相似。具体地说，根和叶的木质部压力势在24小时内变得更负，而根木质部汁液的渗透势保持不变。压力势的下降与营养液渗透势的下降密切相关。相反，在营养介质中添加聚乙二醇400导致根木质部汁液渗透势降低；木质部的这种渗透调节足够大，足以建立进入水的渗透梯度，并在营养溶液渗透势为−4.8bar时引起渗漏。根和叶木质部的压力势只有在营养液渗透势低于−4.8bar时才变为负值。在聚乙二醇400存在下，大约一半的木质部渗透调节是由根木质部中K+、Na+、Ca2+和Mg2+的积累增加引起的。这些研究表明，聚乙二醇6000等较大的聚乙二醇分子比聚乙二醇400等较小的分子更有助于模拟土壤水分胁迫。
The water relations of pepper plants (Capsicum frutescensL.) under conditions conducive to guttation were studied to evaluate the control of plant water stress with polyethylene glycols. The addition of polyethylene glycol 6000 to the nutrient solution resulted in water relations similar to those expected in soil at the same water potentials. Specifically, xylem pressure potential in the root and leaf became more negative during a 24-hour treatment period, while osmotic potential of the root xylem sap remained constant. The decrease in pressure potential was closely correlated with the decrease in osmotic potential of the nutrient solution. In contrast, the addition of polyethylene glycol 400 to the nutrient medium resulted in a reduction of osmotic potential in the root xylem sap; this osmotic adjustment in the xylem was large enough to establish an osmotic gradient for entry of water and cause guttation at a nutrient solution osmotic potential of −4.8 bars. Pressure potential in the root and leaf xylem became negative only at nutrient solution osmotic potentials lower than −4.8 bars. About half of the xylem osmotic adjustment in the presence of polyethylene glycol 400 was caused by increased accumulation of K+, Na+, Ca2+, and Mg2+in the root xylem. These studies indicate that larger polyethylene glycol molecules such as polyethylene glycol 6000 are more useful for simulating soil water stress than smaller molecules such as polyethylene glycol 400.