Radin J W, Parker L L
United States Department of Agriculture, Science and Education Administration, Western Cotton Research Laboratory, Phoenix, Arizona 85040.
Plant Physiol. 1979 Sep;64(3):499-501. doi: 10.1104/pp.64.3.499.
Nitrogen deficiency in cotton plants (Gossypium hirsutum L.) considerably increased the sensitivity of stomata to water stress. At air temperatures of 27, 35, and >/=40 C, threshold potentials for complete stomatal closure were -10, -15, and -26 bars in N-deficient plants and -20, -20, and -30 bars in high-N plants, respectively. This three-way interaction among N supply, water potential, and air temperature was similar to that exerted on leaf expansion. The effects of N supply on stomatal behavior could not be explained on the basis of either osmotic or structural considerations. Rather, effects of N deficiency on mesophyll and stomata were independent and divergent. Stomatal behavior may impart a stress avoidance type of drought resistance to N-deficient plants.
棉花植株(陆地棉)缺氮会显著增加气孔对水分胁迫的敏感性。在27、35和≥40℃的气温条件下,缺氮植株气孔完全关闭的阈值电位分别为-10、-15和-26巴,高氮植株则分别为-20、-20和-30巴。氮素供应、水势和气温之间的这种三向相互作用与对叶片扩展的作用相似。氮素供应对气孔行为的影响无法基于渗透或结构方面的考虑来解释。相反,缺氮对叶肉和气孔的影响是独立且不同的。气孔行为可能赋予缺氮植株一种避旱型的抗旱性。