Metabolic Studies of Applied Indoleacetic Acid-1-C¹⁴ in Plant Tissues as Affected by Light and 2,4-D Treatment.

Abstract

PLANT PHYSIOLOGY rows of orchards than within the orchards, and the formation of precipitates of only slightly soluble salts on the surfaces of leaves in exposed positions. In the present studies this precipitation occurred on the leaves of the oranges sprayed for 1 second every 30 seconds, but there was none on the leaves under continuous irrigation. Continuous sprinkling is known to be practiced without injury in situations where the same water supply intermittently applied causes severe injury. SUMMARY Lemon and orange leaves accumulated more sodium and chloride when irrigated with sprinklers of the intermittent type during the day than they did when similarly irrigated during the night. They accumulated more when intermittently sprinkled than when continuously sprinkled. Intermittent sprinkling permitted evaporation and concentration of the salts in the water films left on the leaves. In advance of the measurements it was thought that little accumulation could be expected from the concentrations of salts in the initial irrigation water, and this proved to be the case.Comparisons were made of absorption by orange seedlings and by rooted lemon cuttings when the plants were inverted and the tops immersed for overnight periods in aerated single-salt solutions. Foliar absorptions by this procedure supported the earlier results and gave a constancy of cation accumulation except when there were heavy accumulations of chloride in association with particular cations.

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

“…These proportions are in general agreement with those found in our earlier studies (2,4). The fact that our results differ so markedly from those obtained by Fang et al (5) has already been ascribed to the presence in our media of calcium ions whiclh are essential to the normal metabolism of TAA by isolated pea roots (4). The importance of maintaining sterile conditions, especially when using medlia containing sucrose, must be stressed.…”

“…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.…”

Influence of Auxins on in vitro Incorporation of Glycine-C14 in Pea Shoot Proteins

“…Alaska peas wxere gerinaiiitted at rooml temlperature between 2 sheets of moist paper in tlle dark for 4 to 5 days as described previously (4). The tioIns per minute in a water bath nmaintained at 25°.…”

Studies on 3-Indoleacetic Acid Metabolism. V. Effect of Calcium Ions on 3-indoleacetic Acid Uptake and Metabolism by Pea Roots

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It has previously been shown that indoleacetic acid (IAA) applied to pea roots is in part clegraded and in part conjugated witlh aspartic acid to form indoleacetylaspartic acicl (IAAspA) (2,6 NaHCO, which was then added to the ethanol evaporate; this step was found to be unnecessary.) If IAA and IAAspA were both present in root tissues, methodl 1 was used for colorinmetric ainalxysis.

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