Plant Physiology Research Group, Biology Department, University of Calgary, Calgary, Alberta, Canada T2N 1N4.
Plant Physiol. 1985 Dec;79(4):1086-9. doi: 10.1104/pp.79.4.1086.
Abscisic acid (ABA) levels in 3-mm apical root segments of slowly droughted sunflower plants (Helianthus annuus L. cv Russian Giant) were analyzed as the methyl ester by selected ion monitoring gas chromatography-mass spectrometry using characteristic ions. An internal standard, hexadeuterated ABA (d6ABA) was used for quantitative analysis. Sunflower seedlings, grown in aeroponic chambers, were slowly droughted over a 7-day period. Drought stress increased ABA levels in the root tips at 24, 72, and 168 hour sample times. Control plants had 57 to 106 nanograms per gram ABA dry weight in the root tips (leaf water potential, -0.35 to -0.42 megapascals). The greatest increase in ABA, about 20-fold, was found after 72 hours of drought (leaf water potential, -1.34 to -1.47 megapascals). Levels of ABA also increased (about 7- to 54-fold) in 3-mm apical root segments which were excised and then allowed to dessicate for 1 hour at room temperature.
用特征离子选择离子监测气相色谱-质谱法对缓慢干旱处理的向日葵植株（Helianthus annuus L. cv Russian Giant） 3mm 顶端根段中的脱落酸（ABA）水平进行了分析，并用甲酯形式表示。采用内标物氘代脱落酸（d6ABA）进行定量分析。在气培室内生长的向日葵幼苗经过 7 天的缓慢干旱处理。干旱胁迫在 24、72 和 168 小时取样时间增加了根尖中的 ABA 水平。对照植株根尖中的 ABA 含量为 57 至 106 纳克/克干重（叶片水势为-0.35 至-0.42 兆帕斯卡）。在干旱 72 小时后，ABA 增加了约 20 倍（叶片水势为-1.34 至-1.47 兆帕斯卡）。在切除 3mm 顶端根段并在室温下干燥 1 小时后，ABA 水平也增加了（约 7 至 54 倍）。
