Enhancing grain size in durum wheat using RNAi to knock-down GW2 genes.

Sestili F., Pagliarello R., Zega A., Saletti R., Pucci A., Botticella E., Masci S., Tundo S., Moscetti I., Foti S., Lafiandra D. 2019 Enhancing grain size in durum wheat using RNAi to knock-down GW2 genes. Theoretical and Applied Genetics, 132(2): 419-429 https://doi.org/10.1007/s00122-018-3229-9.

Abstract
Key message Knocking down GW2 enhances grain size by regulating genes encoding the synthesis of cytokinin,
gibberellin, starch and cell wall.
Abstract 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.