Comparison of the levels of six endogenous gibberellins in roots and shoots of spinach in relation to photoperiod
This communication describes the distribution of gibberellins (GAs) in roots and shoots of spinach in relation to photoperiod. From previous work shoots were known to contain GA/sub 53/, GA/sub 44/, GA/sub 19/, GA/sub 17/, GA/sub 20/, and GA/sub 29/. We now show by combined gas chromatography-mass spectrometry that roots contain gas chromatography-selected ion current monitoring. Neither GA/sub 17/ nor GA/sub 20/ were detected in root extracts. Analysis by the d-5 corn bioassay also showed no effect of photoperiodic treatment on the levels of GA-like substances in root extracts. Both phloem and xylem exudates had patterns of GA-like activity similar to those found in shoots and roots, respectively. Moreover, foliar application of (/sup 3/H)GA/sub 20/ resulted in the transport of label from the shoot to the roots. Over half of the label in the roots represented unmetabolized (/sup 3/H)GA/sub 20/, indicating that part of the GA/sub 20/ in the phloem is transported to the roots. Consequently, if GA/sub 20/ is made in, or transported to the roots, it is rapidly metabolized in that organ. This is a clear indication that regulation of GA metabolism is greatly different in roots and shoots.
- Research Organization:
- Michigan State Univ., East Lansing, MI (United States)
- DOE Contract Number:
- EY-76-C-02-1338
- OSTI ID:
- 6761679
- Journal Information:
- Plant Physiol.; (United States), Vol. 66:4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GIBBERELLIC ACID
TISSUE DISTRIBUTION
PHOTOPERIOD
BIOLOGICAL EFFECTS
PLANTS
PHOTOSENSITIVITY
BIOASSAY
DAILY VARIATIONS
ENZYME ACTIVITY
GAS CHROMATOGRAPHY
MASS SPECTROSCOPY
METABOLISM
PLANT GROWTH
PLANT STEMS
PLANT TISSUES
QUANTITATIVE CHEMICAL ANALYSIS
QUANTITY RATIO
ROOTS
TIME DEPENDENCE
TRACE AMOUNTS
TRANSLOCATION
VISIBLE RADIATION
CARBOXYLIC ACIDS
CHEMICAL ANALYSIS
CHROMATOGRAPHY
DISTRIBUTION
ELECTROMAGNETIC RADIATION
ESTERS
GROWTH
HETEROCYCLIC COMPOUNDS
HYDROXY ACIDS
LACTONES
ORGANIC ACIDS
ORGANIC COMPOUNDS
RADIATIONS
SENSITIVITY
SEPARATION PROCESSES
SPECTROSCOPY
VARIATIONS
550500* - Metabolism
550200 - Biochemistry