ABSCISIC-ACID CONCENTRATIONS AND FLUXES IN DROUGHTED CONIFER SAPLINGS
ABSCISIC-ACID CONCENTRATIONS AND FLUXES IN DROUGHTED CONIFER SAPLINGS
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DOI：
10.1111/j.1365-3040.1995.tb00539.x
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发表时间：
1995-01-01
影响因子：
7.3
通讯作者：
KHALIL, AAM
中科院分区：
文献类型：
--
作者：
JACKSON, GE;IRVINE, J;KHALIL, AAM
本文首次研究了一个干旱周期中针叶树木质部汁液中脱落酸(ABA)的浓度和通量。樟子松和云杉的汁液中ABA浓度随着干旱的加剧而增加11倍，有明显的日变化趋势，在接近中午时达到最大值(6-8 mmolABA m(-3))，用木质部ABA浓度乘以汁液流速来计算ABA的通量。中午干旱植株的ABA通量通常不高于对照，这是由于当时干旱植株的液流很低，而干旱植株的ABA通量在上午高于对照，我们假设气孔对这些‘早晨剂量’有响应。气孔导度g(S)与叶片膨胀率或ABA通量不能统计相关，但g(S)确实与木质部ABA浓度呈负指数关系。松树比云杉对干旱更适应。干旱处理后第6天，云杉的ABA浓度升高，气孔导度下降，渗透势下降。
We present the first study of abscisic acid (ABA) concentrations and fluxes in the xylem sap of conifers during a drought cycle, In both Pinus sylvestris and Picea sitchensis the concentration of ABA in the sap rose 11-fold as the drought progressed, There were clear diurnal trends in this concentration, which reached its maximum (6-8 mmol ABA m(-3)) near the middle of the day, The fluxes of ABA were calculated by multiplying the xylem ABA concentration by the sap flow rate. The ABA fluxes in the droughted plants in the middle of the day were usually no higher than those of the controls, as a result of the very low sap flow in the droughted plants at that time, However, the ABA flux in the droughted plants was higher than in the controls in the morning, and we postulate that the stomata are responding to these 'morning doses'.Stomatal conductance, g(s), could not be related statistically to leaf turgor or to the ABA flux, However, g(s) did display a negative exponential relationship with ABA concentration in the xylem.Pinus displayed more acclimation to drought than Picea, Its ABA concentration rose and its stomatal conductance fell at day 6 of the drought, as opposed to day 17 for Picea, and its osmotic potential fell during the drought treatment.