Bethlenfalvay G J, Brown M S, Franson R L
U.S. Department of Agriculture, Agricultural Research Service, Western Regional Research Center, Albany, California 94710.
Plant Physiol. 1990 Oct;94(2):723-8. doi: 10.1104/pp.94.2.723.
Soybean (Glycine max [L.] Merr.) plants were colonized by the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe (VAM plants) or fertilized with KH(2)PO(4) (nonVAM plants) and grown for 50 days under controlled conditions. Plants were harvested over a 4-day period during which the soil was permitted to dry slowly. The harvest was terminated when leaf gas exchange was no longer measurable due to drought stress. Significantly different effects in shoot water content, but not in shoot water potential, were found in VAM and nonVAM plants in response to drought stress. Leaf conductances of the two treatments showed similar response patterns to changes in soil water and shoot water potential but were significantly different in magnitude and trend relative to shoot water content. The relationships between transpiration, CO(2) exchange and water-use efficiency (WUE) were the same in VAM and nonVAM plants in response to decreasing soil water and shoot water potential. As a function of shoot water content, however, WUE showed different response patterns in VAM and nonVAM plants.
大豆（Glycine max [L.] Merr.）植株接种了泡囊丛枝菌根（VAM）真菌摩西球囊霉（Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe）（VAM植株），或施以磷酸二氢钾（非VAM植株），并在可控条件下生长50天。在4天时间内对植株进行收获，在此期间让土壤缓慢变干。当由于干旱胁迫叶片气体交换无法再测量时，收获结束。在干旱胁迫下，VAM植株和非VAM植株在地上部含水量方面存在显著不同的影响，但在地上部水势方面没有差异。两种处理的叶片导度对土壤水分和地上部水势变化呈现相似的响应模式，但相对于地上部含水量，其在幅度和趋势上存在显著差异。在VAM植株和非VAM植株中，随着土壤水分和地上部水势降低，蒸腾作用、CO₂交换与水分利用效率（WUE）之间的关系相同。然而，作为地上部含水量的函数，VAM植株和非VAM植株中WUE呈现不同的响应模式。
