The plant hormone auxin can be regulated by formation and hydrolysis of amide-linked indole-3-acetic acid (IAA) conjugates. Here, we report the characterization of the dominant Arabidopsis iaa-leucine resistant3 (ilr3-1) mutant, which has reduced sensitivity to IAA-Leu and IAA-Phe, while retaining wild-type responses to free IAA. The gene defective in ilr3-1 encodes a basic helix-loop-helix leu...

Indoleacetic acid (IAA) oxidase has been reported to be involved in plant growth because of its alleged role in the control of endogenous IAA levels. This purported role was reevaluated in terms of the properties and subcellular location of the enzyme in etiolated pea (Pisum sativum L. var. Alaska) epicotyls.The enzymic properties of IAA oxidase in the floating pea epicotyl segments are similar...

Effect of growth hormones i.e., gibberellic acid (GA3), indole-3-acetic acid (IAA) and Kinetin was studied on the root of Cicer arietinum L. after forty-five and sixty days of treatments and compared with control. The application of GA3 alone and in combination with IAA or Kinetin or both caused extension growth and insignificant increase in the number of rootlets accompanied with decrease in t...

The endogenous levels of indole-3-acetic acid (IAA) and phenyl acetic acid (PAA) were estimated in developing seeds of two different varieties of Cajanus cajan: Black seeded variety (V1, big seeded) and B. D. N2 (V2, small seeded). Antibodies against IAA and PAA were raised in rabbits. By competitive ELISA, free and conjugated IAA and free forms of PAA were estimated. Growth analysis of seeds w...

Strains of Vibrio spp. isolated from roots of the estuarine grasses Spartina alterniflora and Juncus roemerianus produce the phytohormone indole-3-acetic acid (IAA). The colorimetric Salkowski assay was used for initial screening of IAA production. Gas chromatography-mass spectroscopy (GC-MS) was then employed to confirm and quantify IAA production. The accuracy of IAA quantification by the Sal...

Auxin is central to many aspects of plant development; accordingly, plants have evolved several mechanisms to regulate auxin levels, including de novo auxin biosynthesis, degradation, and conjugation to sugars and amino acids. Here, we report the characterization of an Arabidopsis thaliana mutant, IAA carboxyl methyltransferase1-dominant (iamt1-D), which displayed dramatic hyponastic leaf pheno...

Auxin is a phytohormone involved in cell elongation and division. Levels of indole-3-acetic acid (IAA), the primary auxin, are tightly regulated through biosynthesis, degradation, sequestration, and transport. IAA is sequestered in reversible processes by adding amino acids, polyol or simple alcohols, or sugars, forming IAA conjugates, or through a two-carbon elongation forming indole-3-butyric...

Tang and Bonner (16) have described an indoleacetic acid (IAA) oxidase system in pea epicotyls, and also an IAA oxidase inhibitor (17). These findings have been confirmed and extended by others (5-8, 18) and an IAA oxidase has been found in several plants, including beans (18) and pineapple leaf tissue (9). The presence of an inhibitor of IAA oxidation has not previously been shown in the pinea...

Indole-3-acetic acid (IAA) was detected in the ether extracts of culture filtrates of indigotin-producing strains of the basidiomycete Schizophyllum commune. Several solvents, known to give distinctly different R(F) values for IAA, and 3 location reagents gave identical results with synthetic IAA and IAA found in the extract. Confirmation was obtained by the Avena straight growth test, split pe...