Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, S-901 83, Umeå, Sweden.
Planta. 1984 May;161(2):148-55. doi: 10.1007/BF00395475.
Scots pine (Pinus sylvestris L.) seedlings grown in nutrient solution in controlled-environment chambers were used. The effects of a shortday (SD, early autumn) treatment on growth and the content of "free" and alkaline hydrolysable abscisic acid (ABA) in shoots and roots were investigated. The weekly relative growth rates of seedlings grown continuously under long-day (LD, summer) conditions were stable at approx. 0.08 g g(-1) d(-1) between weeks four and eight from germination. Weekly relative growth rates of seedlings transferred to SD conditions decreased rapidly to a then stable level of approx. 0.04 g g(-1) d(01). Shoot elongation ceased within two weeks of SD treatment. The content of both "free" and alkaline hydrolysable ABA was approx. 40-50% higher in shoots of seedlings grown for five weeks in LD plus one week in SD than in shoots of seedlings grown for five or six weeks in LD. Two additional weeks of SD did not change the "free" ABA content. Three weeks in simulated late autumn (SD but decreased temperatures) and three weeks in simulated winter (lower light intensity and temperature) further increased the content of "free" ABA in the shoots. A transfer back to LD conditions reduced the ABA content to a level equal to the level found during the first LD period. The recovery of radioactive ABA at certain times after application ofr[(3)H] ABA was the same in shoots and roots of LD-grown and SD-treated seedlings.
以在营养液中生长于人工气候室内的欧洲赤松（Pinus sylvestris L.）幼苗为材料，研究了短日（SD，早秋）处理对生长和芽及根中“自由态”和碱性水解型脱落酸（ABA）含量的影响。在长日（LD，夏季）条件下连续生长的幼苗，从发芽后第 4 周到第 8 周，每周的相对生长率稳定在约 0.08 g g(-1) d(-1)。转移到 SD 条件下的幼苗的每周相对生长率迅速下降至约 0.04 g g(-1) d(-1)的稳定水平。SD 处理后两周内，芽的伸长停止。在 LD 条件下生长 5 周，然后在 SD 条件下生长 1 周的幼苗芽中“自由态”和碱性水解型 ABA 的含量比在 LD 条件下生长 5 或 6 周的幼苗芽中“自由态”和碱性水解型 ABA 的含量高约 40-50%。再增加两周的 SD 不会改变“自由态”ABA 的含量。在模拟晚秋（SD 但降低温度）和模拟冬季（光照强度和温度降低）条件下再培养 3 周，进一步增加了芽中“自由态”ABA 的含量。回到 LD 条件下，ABA 含量降低到与 LD 第一个周期相同的水平。在 LD 生长和 SD 处理的幼苗芽和根中，r[(3)H]ABA 处理后特定时间 ABA 的放射性回收是相同的。
