Abscisic acid and cessation of apical growth in Salix pentandra

Abstract

Effects of exogenous abscisic acid (ABA) on growth and transpiration in seedlings of two ecotypes of Salix pentandra L. were studied in phytotron experiments. Application of ABA resulted in increased stomatal resistance, reduced transpiration and reduced growth rate. ABA did not induce cessation of apical growth in seedlings grown under a 24‐h photoperiod. The content of endogenous ABA in seedlings grown under 24‐h (LD) or 12‐h (SD) photoperiods was analysed from purified methanol extracts using gas chromatography and electron capture detection. No significant differences were found in the ABA contents of LD‐ and SD‐grown plants. SD‐induced cessation of apical growth was not associated with increased stomatal resistance or reduced transpiration rate.

The effect of drought and enhanced UV-B radiation on the growth and physiological traits of two contrasting poplar species

“…Then, samples of 30-50 mg of plant material were homogenized in 5 ml of 50 mM sodium phosphate buffer, pH 7.0 with 0.02% sodium diethyldithiocarbamate as antioxidant and 30 ng [ 2 H 4 ] ABA as an internal standard. ABA was measured by gas chromatography-mass spectrometry as described by Jensen et al (1986) with selective ion monitoring (SIM). Ions at 190.1 and 194.1 were monitored, and the amount of ABA in the sample was calculated using a standard curve drawn from the area ratios of known amounts of ABA and [ 2 H 4 ] ABA.…”

Different responses of two contrasting Populus davidiana populations to exogenous abscisic acid application

“…The flow rate was 2 ml min −1 and a 2-min fraction (retention time 16.2-18.2, ABA eluted at 17.2 min) was collected and reduced to dryness (SpeedVac). ABA was measured by gas chromatography-mass spectrometry as described by Jensen et al (1986) with selective ion monitoring (SIM). Ions at 190.1 and 194.1 were monitored and amount of ABA in the sample was calculated using a standard curve drawn from the area ratios of known amounts of ABA and [ 2 H 4 ] ABA.…”

Seasonal changes in endogenous ABA and IAA and the influence of applied ABA and auxin in relation to shoot growth and abscission in Valencia Orange (Citrus sinensis (L.) Osbeck)

“…In Salix short days induce cessation of shoot extension (Junttila, 1976) . This is not correlated with endogenous ABA (Johansen et al ., 1986) and changes in endogenous gibberellins appear to be involved (Junttila, 1976 Junttila andJensen, 1988) . Research by Jones et al, 1976, andGoldschmidt (1984), with alternately bearing citrus, suggested that the elevated levels of ABA found in leaves, stems and buds were correlated with the extended quiescence of buds on trees bearing a heavy crop of fruit.…”