Seed and hormonal regulation of gibberellin 20-oxidase expression in pea pericarp

• Published in: Plant physiology (Bethesda) Vol. 115; no. 1; pp. 123 - 128
• Main Authors: Van Huizen, R, Ozga, J.A, Reinecke, D.M
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Physiologists 01.09.1997
• Subjects: ACIDO GIBERELICO; Actins; ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; ARN MENSAJERO; ARN MESSAGER; Biological and medical sciences; BIOSINTESIS; BIOSYNTHESE; BIOSYNTHESIS; DEVELOPMENTAL STAGES; ENZYMIC ACTIVITY; ETAPAS DE DESARROLLO; EXPRESION GENICA; EXPRESSION DES GENES; Flowering; Fundamental and applied biological sciences. Psychology; GENE EXPRESSION; Gene Regulation and Molecular Genetics; GENETIC REGULATION; GENETICA; GENETICS; GENETIQUE; GIBBERELLINE; Gibberellins; GRAINE; Growth regulators; Hormones; MESSENGER RNA; Metabolism; OXIDOREDUCTASES; OXIDORREDUCTASAS; OXYDOREDUCTASE; Peas; PERICARP; PERICARPE; PERICARPIO; PISUM SATIVUM; Plant physiology and development; Plants; RNA; SEEDS; SEMILLA; STADE DE DEVELOPPEMENT; Auxin; Enzyme; Oxidase; Gibberellin; Biosynthesis; Gene expression; Regulation(control); Leguminosae; Dicotyledones; Pisum sativum; Seed; Angiospermae; Plant growth substance; Spermatophyta; Developmental stage; Oxidoreductases
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.115.1.123

To understand further how seeds, auxin (4-chloroindole-3-acetic acid [4-Cl-IAA]), and gibberellins (GAs) regulate GA biosynthesis in pea (Pisum sativum L.) pericarp at the molecular level, we studied the expression of GA 20-oxidase in this tissue using northern-blot analysis. Pericarp GA 20-oxidase mRNA levels were highest from prepollination (-2 d after anthesis [DAA]) through anthesis (0 DAA), then decreased 3-fold by 2 DAA, and remained at these levels through 6 DAA. The effects of seeds and hormones (4-Cl-IAA and GA3) on the expression of GA 20-oxidase in pea pericarp were investigated over a 36-h treatment period. GA 20-oxidase mRNA levels in 2 DAA pericarp with seeds remained relatively stable throughout the treatment period; however, when the seeds were removed the pericarp transcript levels declined. When 2 DAA deseeded pericarps were treated with 4-Cl-IAA, a significant increase in GA 20-oxidase mRNA levels was detected within 2 h and transcript levels remained elevated for up to 12 h after 4-Cl-IAA application. GA3 significantly decreased GA 20-oxidase mRNA levels in deseeded pericarp within 2 h of application. These data suggest that the previously reported conversion of GA19 to GA20 in pea pericarp is controlled by seeds, 4-Cl-IAA, and GA3 at least in part by regulating GA 20-oxidase mRNA levels in this tissue