Absorption, Distribution, and Destruction of Indoleacetic Acid in Plum Stem Cuttings

Abstract

Rooting of greenwood cuttings of Marianna 2624plum (Priunus cerasifera Ehrh. X P. munsoniana Wight & Hedr.) taken in spring or summer is dependent on the presence of a certain minimum leaf area.Treatment of the basal portion of the cuttings with indoleacetic (IAA) or indolebutyric acid (IBA) sub-stantially increases the number of roots per cutting (20). The site of the auxin action is not known. Perhaps there is a direct effect at the site of application wlhere roots appear. Another possibility is that auxin stimulates mobilization of root-promoting substances from the leaves; these substances would then presumably be translocated basipetally to the site of root initiation.Although much study has been given to the absorption and translocation of auxins in intact plants, very few workers have investigated these phenomena in detached parts of woody plants. Cooper (4), using the standard Avena curvature test to follow movement of IAA in the bark of leafless lemon cuttings found initially relatively large amounts of IAA in the region of treatment; however, 95 per cent of the auxin disappeared during the 1st day, and little auxin was translocated to the apices of the cuttings. Turetskaya (24) followed the distribution of I-13 in soft and hardwood cuttings of various species treated with I'31-labeled-p-iodophenoxyacetic acid. In the hardwood cuttings the maximum I13' accumulation occurred in the base of the stem where the roots were formed. Decreasing amounts of f131 were found in xylem, bark, and buds, in that order. Turetskaya (25) followed the movement of C14-carboxyl-labeled naphthaleneacetic acid in leafy cuttings of balsam, cherry, and currant, and found some evidence that the NAA was metabolized.The present study was designed to follow the absorption, translocation, and persistence of C14 from alpha-labeled IAA in cuttings of Marianna 2624 plum. MATERIALS AND METHODS

Evaluation of Propagation of Chinese Hibiscus (<i>Hibiscus rosa-sinensis</i>) through Stenting Method in Response to Different IBA Concentrations and Rootstocks

“…According to Hartmann et al [2], one of the best rooting promoters is the IBA due to its fast auxin activity and an enzymatic system of fairly slow destruction. Strydum and Hartman [11] compared respiration level of treated cuttings with exogenous auxin and control plants; he found that positive effect of auxin is related to increase of level of respiration, high level of amino acid storage at the base of cuttings 24 hours after treatment with auxin. These processes occur simultaneously with increased nitrogen material content at the base of cuttings that move toward upper part of cutting as asparagine does.…”

Studies on 3-indoleacetic acid metabolism. VII. Metabolism of radioactive 3-indoleacetic acid by pea roots

“…These conjugates have been observed to form only in intact tissues, while in homogenized tissue extracts the IAA molecule is degraded by oxidative decarboxylation, ring opening, or both (8). In previous studies by others on IAA metabolism of intact tissues using radioactive IAA labeled in the side-chain (5,11) it was found that the carboxyl group (-1-C14) and, after a lag period, the methylene group (-2-C'4) yielded respiratory C'140,; the chemical nature of the dlecarboxylated metabolites remained unknown.…”

Adventitious Root Formation in Relation to the Uptake and Distribution of Supplied Auxin

“…One such example is the dependency of rooting of some cuttings on a certain minimum leaf area (e.g. Strydom & Hartmann, 1960). The general observation that the presence of leaves markedly enhances the response of cuttings to supplied auxin has been widely accepted as evidence for the existence of other specific ' leaf factors' essential for root formation (e.g.…”