Isolation and Regulation of Accumulation of a Minor Chromoplast-Specific Protein from Cucumber Corollas

Autor: Alexander Vainstein, Michael Vishnevetsky, Yael Libal-Weksler, Mariana Ovadis
Rok vydání: 1997
Předmět:
Zdroj: Plant Physiology. 113:59-63
ISSN: 1532-2548
0032-0889
DOI: 10.1104/pp.113.1.59
Popis: The differentiation of chloroplasts to chromoplasts in cucumber (Cucumis sativus L.) corollas parallels flower development. Chromoplast biogenesis involves chlorophyll degradation, carotenoid accumulation, and the appearance of a new set of proteins. To study factors involved in chromoplast biogenesis in floral tissues, a minor (in abundance) protein of about 14 kD, CHRD (chromoplast protein D), was isolated from cucumber corolla chromoplasts. Immunological characterization revealed that the protein is chromoplast-specific and that its steady-state level in corollas increases in parallel to flower development. The protein was not detected in cucumber leaves or fruits. Immunological analysis of corollas and fruits from a variety of other plants also did not reveal cross-reactivity with the CHRD protein antisera. Using an in vitro bud culture system, we analyzed the effect of phytohormones on CHRD expression. Gibberellic acid rapidly enhanced, whereas paclobutrazol down-regulated, the steady-state level of CHRD. Ethylene also down-regulated the protein's steady-state level. It is suggested that hormonal control of chromoplastogenesis is tightly regulated at the tissue/organ level and that mainly developmental signals control carotenoid accumulation in nonphotosynthetic tissues.
Databáze: OpenAIRE