Isolation and characterization of a chromoplast-specific carotenoid-associated protein from Cucumis sativus corollas

• Published in: Plant physiology (Bethesda) Vol. 102; no. 2; pp. 491 - 496
• Main Authors: Smirra, I, Halevy, A.H, Vainstein, A
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Physiologists 01.06.1993
• Subjects: Antibodies; Biological and medical sciences; CAROTENOIDE; CAROTENOIDES; Carotenoids; Cell biochemistry; cell differentiation; Cell physiology; CHLOROPLASTE; Chloroplasts; Chromoplasts; CLOROPLASTO; COROLA; Corolla; COROLLE; CUCUMIS SATIVUS; Development and Growth Regulation; DIFERENCIACION CELULAR; DIFFERENCIATION CELLULAIRE; FLORACION; FLORAISON; Flower buds; Flowering; Fundamental and applied biological sciences. Psychology; Gels; Plant physiology and development; plant proteins; Plants; PLASTE; PLASTIDIOS; PROTEINAS VEGETALES; PROTEINE VEGETALE; Proteins; Flower; Cucurbitaceae; Plastid; Cucumis sativus; Gene expression; Immunological method; Proteins; Regulation(control); Vegetable crop; Dicotyledones; Angiospermae; Pigment protein complex; Chromoplast; Isolation; Spermatophyta; Developmental stage; Differentiation; Localization
• DOI: 10.1104/pp.102.2.491
• ISSN: 0032-0889; 1532-2548

The differentiation of chloroplasts to chromoplasts in corollas of cucumber (Cucumis sativus) is subject to developmental control. To study factors involved in the chloroplast-chromoplast conversion, a chromoplast-specific protein of 35 kD was isolated, and polyclonal antibodies were prepared against it. This protein was found to be a principal component of the carotenoid-protein complex resolved from chromoplast membranes by nondenaturing gel electrophoresis. Immunological studies revealed that expression of this protein is regulated in a temporal and tissue-specific manner. Its steady-state level increased in parallel with flower development and carotenoid accumulation, peaking in mature flowers and then rapidly decreasing to very low levels. The protein was not detectable in cucumber leaves or fruits. To ascertain whether an organ-specific system regulates the chloroplast-chromoplast conversion and to enable future molecular studies of factors involved in this regulation, an in vitro bud culture system was established. Patterns of expression of the 35-kD protein and carotenoids in corollas of detached buds were similar to those in intact buds