Enhancing grain size in durum wheat using RNAi to knockdown GW2 genes
Knocking down GW2 enhances grain size by regulating genes encoding the synthesis of cytokinin, gibberellin, starch and cell wall.
Raising crop yield is a priority task in the light of the continuing growth of the world's population and the inexorable loss of arable land to urbanization. Here, the RNAi approach was taken to reduce the abundance of Grain Weight 2 (GW2) transcript in the durum wheat cultivar Svevo. The effect of the knockdown was to increase the grains' starch content by 10–40%, their width by 4–13% and their surface area by 3–5%. Transcriptomic profiling, based on a quantitative real-time PCR platform, revealed that the transcript abundance of genes encoding both cytokinin dehydrogenase 1 and the large subunit of ADP-glucose pyrophosphorylase was markedly increased in the transgenic lines, whereas that of the genes encoding cytokinin dehydrogenase 2 and gibberellin 3-oxidase was reduced. A proteomic analysis of the non-storage fraction extracted from mature grains detected that eleven proteins were differentially represented in the transgenic compared to wild-type grain: some of these were involved, or at least potentially involved, in cell wall development, suggesting a role of GW2 in the regulation of cell division in the wheat grain.
The research was financially supported by Italian Ministry of Education, University and Research (MIUR): project PRIN 2010Z77XAX_001 “Identification and characterization of yield- and sustainability-related genes in durum wheat” and in the frame of the MIUR initiative “Departments of excellence”, Law 232/2016. The Bionanotech Research and Innovation Tower (BRIT, University of Catania) is gratefully acknowledged for making available the Orbitrap Fusion mass spectrometer.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
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