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TRANSLOCATION OF APPLIED GIBBERELLIN IN BEAN SEEDLINGS
Author(s) -
Chin Ting Yun,
Lockhart James A.
Publication year - 1965
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1965.tb07254.x
Subject(s) - biology , apex (geometry) , elongation , shoot , chromosomal translocation , botany , gibberellin , darkness , leaflet (botany) , horticulture , main stem , biochemistry , materials science , gene , metallurgy , ultimate tensile strength
The direction and extent of GA transport in Pinto beans has been studied. The increase in growth rate was used as a measure of the amount of GA which reached the stem apex. The evidence showed that a similar increase in stem growth occurred whether GA was applied to the first trifoliolate leaf or to the apex of the shoot, but considerably less elongation resulted when GA was applied to primary leaves. When leaves were treated with GA after remaining in darkness for extended times, no increase in stem elongation was observed; however, growth was promoted when the plants were returned to light. The time required for a sufficient amount of GA to be translocated from the leaf to increase stem growth is less than 1 hour. The maximum growth response was found when the treated leaf was left on the plant for 3 or more hours. A study of GA movement in two‐branched plants was made. The untreated branch showed no growth response when GA was applied to the apex of the other branch, even if the dose of GA was 20 × greater than a saturating dose. Similar results were observed when GA was applied to the first trifoliolate leaf. Considerable GA moved from a mature leaf to the opposite shoot if this untreated branch had been defoliated. The pattern of GA movement to the opposite shoot was dependent on the position of the treated leaf on the shoot. It is concluded that the movement of applied GA is related to carbohydrate transport within the plant.