Identification and localization of a caleosin in olive (Olea europaea L.) pollen during in vitro germination.
In plant organs and tissues, the neutral storage lipids are confined to discrete spherical organelles called oil bodies. Oil bodies from plant seeds contain 0.6-3% proteins, including oleosins, steroleosins, and caleosins. In this study, a caleosin isoform of approximately 30 kDa was identified in the olive pollen grain. The protein was mainly located at the boundaries of the oil bodies in the cytoplasm of the pollen grain and the pollen tube. In addition, caleosins were also visualized in the cytoplasm at the subapical zone, as well as in the tonoplast of vacuoles present in the pollen tube cytoplasm. The cellular behaviour of lipid bodies in the olive pollen was also monitored during in vitro germination. The number of oil bodies decreased 20-fold in the pollen grain during germination, whereas the opposite tendency occurred in the pollen tube, suggesting that oil bodies moved from one to the other. The data suggest that this pollen caleosin might have a role in the mobilization of oil bodies as well as in the reorganization of membrane compartments during pollen in vitro germination.
Zienkiewicz
Krzysztof
K
Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín (CSIC), Profesor Albareda 1, 18008, Granada, Spain.
Castro
Antonio J
AJ
Alché
Juan de Dios
Jde D
Zienkiewicz
Agnieszka
A
Suárez
Cynthia
C
Rodríguez-García
María Isabel
MI
D015153:Blotting, Western; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D013058:Mass Spectrometry; D031658:Olea / Q000378:metabolism* / Q000502:physiology; D010940:Plant Proteins / Q000378:metabolism*; D011058:Pollen / Q000378:metabolism* / Q000502:physiology
D002135:Calcium-Binding Proteins; D010940:Plant Proteins; C402836:caleosin protein, Sesamum indicum