Silencing of Mediates Expression of Other Genes to Increase Yield Parameters in Wheat.

, (cytokinin oxidase/dehydrogenase) family genes influence the development of wheat plants by the specific regulation of cytokinin content in different organs. However, their detailed role is not known. The , highly and specifically expressed in developing spikes and in seedling roots, was silenced by RNAi-mediated gene silencing via and the effect of silencing was investigated in 7 DAP (days after pollination) spikes of T and T generations. Various levels of silencing in both generations influence different models of co-expression with other genes and parameters of yield-related traits. Only a high level of silencing in T resulted in strong down-regulation of , up-regulation of , , and (), and a high yielding phenotype. This phenotype is characterized by a higher spike number, grain number, and grain yield, but lower thousand grain weight (TGW). The content of most of cytokinin forms in 7 DAP spikes of silenced T lines increased from 23% to 76% compared to the non-silenced control. The CKs cross talk with other phytohormones. Each of the tested yield-related traits is regulated by various up- or down-regulated genes and phytohormones. The coordinated effect of silencing on the expression of other genes, phytohormone levels in 7 DAP spikes, and yield-related traits in silenced T lines is presented.