Gibberellins and gravitropism in maize shoots: endogenous gibberellin-like substances and movement and metabolism of (/sup 3/)gibberellin A

Journal Article · Sun Mar 01 00:00:00 EST 1987 · Plant Physiol.; (United States)

DOI:https://doi.org/10.1104/pp.83.3.645· OSTI ID:6438445

Rood, S B; Kaufman, P B; Abe, H; Pharis, R P

(/sup 3/H)Gibberellin A/sub 20/(GA/sub 20/) of high specific radioactivity was applied equilaterally in a ring of microdrops to the internodal pulvinus of shoots of 3-week-old vertical normal maize (Zea mays L.), and to a pleiogravitropic (prostrate) maize mutant, lazy (la). All plants converted the (/sup 3/H)GA/sub 1//sup -/ and (/sup 3/H)GA/sub 29/-like metabolites as well as to several metabolites with the partitioning and chromatographic behavior of glucosyl conjugates of (/sup 3/H)GA/sub 1/(/sup 3/H)GA/sub 29/, and (/sup 3/H)GA/sub 8/. The tentative identification of these putative (/sup 3/H)GA glucosyl conjugates was further supported by the release of the free (/sup 3/H)GA moiety after cleavage with cellulase. Within 12 hours of the (/sup 3/H)GA/sub 20/ feed, there was a significantly higher proportion of total radioactivity in lower than in upper halves of internode and leaf sheaf pulvini in gravistimulated normal maize. Further, there was a significantly higher proportion of putative free GA metabolites of (/sup 3/H)GA/sub 20/, especially (/sup 3/H) GA/sub 1/, in the lower halves of normal maize relative to upper halves. The differential localization of the metabolites between upper and lower halves was not apparent in the pleiogravitropic mutant, la. Endogenous GA-like substances were also examined in gravistimulated maize shoots. Forty-eight hours after gravistimulation of 3-week-old maize seedlings, endogenous free GA-like substances in upper and lower leaf sheath and internode pulvini halves were extracted, chromatographed, and bioassayed using the Tanginbozu dwarf rice microdroassay. Lower halves contained higher total levels of GA-like activity.

• Research Organization: Univ. of Lethbridge, Alberta
• OSTI ID: 6438445
• Journal Information: Plant Physiol.; (United States), Vol. 83:3
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CELLULASE
ENZYME ACTIVITY
GIBBERELLIC ACID
MEMBRANE TRANSPORT
METABOLISM
MAIZE
PLANT GROWTH
BIOASSAY
CHROMATOGRAPHY
METABOLITES
TRACER TECHNIQUES
TRITIUM COMPOUNDS
CARBOXYLIC ACIDS
CEREALS
ENZYMES
ESTERS
GLYCOSYL HYDROLASES
GRASS
GROWTH
HETEROCYCLIC COMPOUNDS
HYDROLASES
HYDROXY ACIDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LACTONES
O-GLYCOSYL HYDROLASES
ORGANIC ACIDS
ORGANIC COMPOUNDS
PLANTS
SEPARATION PROCESSES
550501* - Metabolism- Tracer Techniques