Cell-type proteomic and metabolomic resolution of early and late grain filling stages of wheat endosperm

Shuang Zhang, Arindam Ghatak, Mitra Mohammad Bazargani, Hannes Kramml, Fujuan Zang, Shuang Gao, Živa Ramšak, Kristina Gruden, Rajeev K. Varshney, Dong Jiang, Palak Chaturvedi, Wolfram Weckwerth

The nutritional value of wheat grains, particularly their protein and metabolite composition, is a result of the grain-filling process, especially in the endosperm. Here, we employ laser microdissection (LMD) combined with shotgun proteomics and metabolomics to generate a cell type-specific proteome and metabolome inventory of developing wheat endosperm at the early (15 DAA) and late (26 DAA) grain-filling stages. We identified 1803 proteins and 41 metabolites from four different cell types (aleurone (AL), sub-aleurone (SA), starchy endosperm (SE) and endosperm transfer cells (ETCs). Differentially expressed proteins were detected, 67 in the AL, 31 in the SA, 27 in the SE and 50 in the ETCs between these two-time points. Cell-type accumulation of specific SUT and GLUT transporters, sucrose converting and starch biosynthesis enzymes correlate well with the respective sugar metabolites, suggesting sugar upload and starch accumulation via nucellar projection and ETC at 15 DAA in contrast to the later stage at 26 DAA. Changes in various protein levels between AL, SA and ETC support this metabolic switch from 15 to 26 DAA. The distinct spatial and temporal abundances of proteins and metabolites revealed a contrasting activity of nitrogen assimilation pathways, e.g. for GOGAT, GDH and glutamic acid, in the different cell types from 15 to 26 DAA, which can be correlated with specific protein accumulation in the endosperm. The integration of cell-type specific proteome and metabolome data revealed a complex metabolic interplay of the different cell types and a functional switch during grain development and grain-filling processes.

Functional and Evolutionary Ecology, Research Platform Vienna Metabolomics Center
External organisation(s)
Molecular Systems Biology Lab (MOSYS), National Technique Innovation Center for Regional Wheat Production/Key Laboratory of Crop Ecophysiology, Nanjing Agricultural University, Iranian Research Organization for Science and Technology (IROST), National Institute of Biology, State Agricultural Biotechnology Centre, Murdoch University
Plant Biotechnology Journal
No. of pages
Publication date
Peer reviewed
Austrian Fields of Science 2012
106031 Plant physiology, 106037 Proteomics, 106057 Metabolomics, 106028 Plant anatomy
ASJC Scopus subject areas
Biotechnology, Agronomy and Crop Science, Plant Science
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