Dynamic changes in the date palm fruit proteome during development and ripening. (6th August 2014)

• Record Type: Journal Article
• Authors: Marondedze, Claudius; Gehring, Christoph; Thomas, Ludivine
• Is Part Of: Horticulture research. Volume 1(2014)
• Publication Date: 2014-08-06
• Subjects: Proteomics; Horticulture -- Research -- Periodicals; 635.072
• DOI: 10.1038/hortres.2014.39
• Languages: English
• ISSNs: 2052-7276

Abstract

Abstract: Date palm ( Phoenix dactylifera ) is an economically important fruit tree in the Middle East and North Africa and is characterized by large cultivar diversity, making it a good model for studies on fruit development and other important traits. Here in gel comparative proteomics combined with tandem mass spectrometry were used to study date fruit development and ripening. Total proteins were extracted using a phenol-based protocol. A total of 189 protein spots were differentially regulated ( p ≤0.05). The identified proteins were classified into 14 functional categories. The categories with the most proteins were 'disease and defense' (16.5%) and 'metabolism' (15.4%). Twenty-nine proteins have not previously been identified in other fleshy fruits and 64 showed contrasting expression patterns in other fruits. Abundance of most proteins with a role in abiotic stress responses increased during ripening with the exception of heat shock proteins. Proteins with a role in anthocyanin biosynthesis, glycolysis, tricarboxylic acid cycle and cell wall degradation were upregulated particularly from the onset of ripening and during ripening. In contrast, expression of pentose phosphate- and photosynthesis-related proteins decreased during fruit maturation. Although date palm is considered a climacteric species, the analysis revealed downregulation of two enzymes involved in ethylene biosynthesis, suggesting an ethylene-independent ripening of 'Barhi' fruits. In summary, this proteomics study provides insights into physiological processes during date fruit development and ripening at the systems level and offers a reference proteome for the study of regulatory mechanisms that can inform molecular and biotechnological approaches to further improvements of horticultural traits including fruit quality and yield. Fruit development: Changes in date palm proteins: Changes in the levels of proteins affected by the maturation of date palm fruit provide insight into the molecular regulation of the process. Scientists led by Claudius Marondedze of the King Abdullah University of Science and Technology in Saudi Arabia observed that the abundances of 189 proteins differ between fruit samples collected 25, 70, 110 and 125 days after pollination. Functional classification of the proteins indicated that the categories 'disease and defense', 'metabolism' and 'unclassified' contained the largest numbers of differentially expressed proteins. Maturation-related regulation of 64 of the proteins differed between dates and other fruits. Twenty-nine have never been identified in fleshy fruits from monocotyledonous plants (one of the two major groups of flowering plants) like the date palm. The findings might suggest unique ways to improve the quality and yields of dates.