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Article|06 Aug 2014|OPEN
Dynamic changes in the date palm fruit proteome during development and ripening
Christoph Gehring1 , Ludivine Thomas2 and Claudius Marondedze,1 ,
1Biological and Environmental Sciences & Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
2Bioscience and Bioengineering Core Facility, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
*Corresponding author. E-mail: claudius.marondedze@kaust.edu.sa

Horticulture Research 1,
Article number: 39 (2014)
doi: https://doi.org/10.1038/hortres.2014.39
Views: 943

Received: 28 Apr 2014
Revised: 29 May 2014
Accepted: 15 Jun 2014
Published online: 06 Aug 2014

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.