USDA-ARS Plant Stress and Water Conservation Research Unit, Texas Tech University, Lubbock, Texas.
Plant Physiol. 1985 Oct;79(2):415-9. doi: 10.1104/pp.79.2.415.
The effects of water deficits on plant morphology and biochemistry were analyzed in two photoperiodic strains of field-grown cotton (Gossypium hirsutum L.). Plants grown under dryland conditions exhibited a 40 to 85% decrease in leaf number, leaf area index, leaf size, plant height, and total weight per plant. Gross photosynthesis decreased from 0.81 to 0.47 milligram CO(2) fixed per meter per second and the average midday water, osmotic, and turgor potentials decreased to -2.1, -2.4, and 0.3 megapascals, respectively.There was a progressive increase in glutathione reductase activity and in the cellular antioxidant system in the leaves of stressed plants compared to the irrigated controls. The stress-induced increases in enzyme activity occurred at all canopy positions analyzed.Irrigation of the dryland plots following severe water stress resulted in a 50% increase in leaf area per gram fresh weight in newly expanded leaves of both strains over the leaves which had expanded under the dryland conditions. Paraquat resistance (a relative measure of the cellular antioxidant system) decreased in the strain T25 following irrigation. Glutathione reductase activities remained elevated in the T25 and T185 leaves which were expanded fully prior to irrigation and in the leaves which expanded following the irrigation treatment.
对在两种光周期条件下生长于田间的棉花（Gossypium hirsutum L.）的植物形态和生物化学受水分亏缺的影响进行了分析。在旱地条件下生长的植株的叶片数、叶面积指数、叶大小、株高和单株总重分别减少了 40%至 85%。总光合作用从 0.81 毫克 CO2 固定/米/秒降至 0.47 毫克，平均中午水势、渗透势和膨压势分别降至-2.1、-2.4 和 0.3 兆帕。与灌溉对照相比，胁迫植株叶片中的谷胱甘肽还原酶活性和细胞抗氧化系统逐渐增加。在分析的所有冠层位置，胁迫诱导的酶活性增加。在严重水分胁迫后对旱地小区进行灌溉，使两个品系中新展开叶片的叶面积/克鲜重比在旱地条件下展开的叶片增加了 50%。灌溉后，T25 品系的百草枯抗性（细胞抗氧化系统的相对衡量指标）下降。在 T25 和 T185 叶片中，谷胱甘肽还原酶活性仍然较高，这些叶片在灌溉前已完全展开，在灌溉处理后展开的叶片中也较高。
