polycotyledon mutant of tomato shows enhanced polar auxin transport

• Published in: Plant physiology (Bethesda) Vol. 133; no. 1; pp. 113 - 125
• Main Authors: Al-Hammadi, A.S.A, Sreelakshmi, Y, Negi, S, Siddiqi, I, Sharma, R
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Biologists 01.09.2003; American Society of Plant Physiologists
• Subjects: 2,3,5-triiodobenzoic acid; Auxins; Biological and medical sciences; Biological Transport - drug effects; Biological Transport - genetics; Cell Size - genetics; Cell Size - physiology; Cotyledon - genetics; Cotyledon - growth & development; Cotyledon - metabolism; Cotyledons; Curvature; Development and Hormone Action; Embryos; Epidermal cells; Flowers - genetics; Flowers - growth & development; Flowers - metabolism; Fundamental and applied biological sciences. Psychology; gravitropism; Gravitropism - genetics; Gravitropism - physiology; Hypocotyls; indole acetic acid; Indoleacetic Acids - metabolism; Inflorescences; Lycopersicon esculentum; mutants; Mutation; Phenotype; Phenotypes; phenotypic variation; physiological transport; Plant growth. Development of the storage organs; Plant Leaves - genetics; Plant Leaves - growth & development; Plant Leaves - metabolism; plant morphology; Plant physiology and development; Plants; pleiotropy; Seedlings; Seeds - genetics; Seeds - growth & development; Seeds - metabolism; Solanum lycopersicum - genetics; Solanum lycopersicum - growth & development; Solanum lycopersicum - metabolism; Solanum lycopersicum var. lycopersicum; tomatoes; Triiodobenzoic Acids - pharmacology; vegetable crops; Vegetative apparatus, growth and morphogenesis. Senescence; Translocation; Auxin; Growth; Phenotype; Dicotyledones; Angiospermae; Lycopersicon esculentum; Development; Plant growth substance; Polarity; Spermatophyta; Solanaceae; Mutation
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.103.025478

The polycotyledon mutant of tomato (Lycopersicon esculentum L. cv Ailsa Craig) showed altered development during embryogenesis and during vegetative and reproductive phases. The phenotype was pleiotropic and included the formation of extra cotyledons, changes in leaf shape, increased number of flowers (indeterminacy) with abnormal floral organs, the formation of epiphyllous structures, and altered gravitropism. The earliest defects were observed at the transition from the globular to the heart stage of embryogenesis with the formation of multiple cotyledons. Epidermal cells in the mutant embryo were smaller and less expanded compared with wild type. Examination of polar auxin transport (PAT) showed a striking enhancement in the case of the mutant. Increase in PAT did not appear to be caused by a decrease in flavonoids because the mutant had normal flavonoid levels. Application of 2,3,5-triiodobenzoic acid, an inhibitor of polar transport of auxin, rescued postgermination phenotypes of young seedlings. Our analysis reveals a level of control that negatively regulates PAT in tomato and its contribution to plant development and organogenesis.