BdVIL4 regulates flowering time and branching through repressing miR156 in ambient temperature dependent way in Brachypodium distachyon

Abstract

Responsing to environmental signals, VERNALIZATION INSENSITIVE 3 (VIN3) family proteins are involved in plant development control by repressing the target genes epigenecticly together with Polycomb Repressive Complex 2 (PRC2) complex. BdVIL4 is a VIN3 like gene in Brachypodium distachyon, preferentially expressed in young tissues spatially. The RNAi plants were constructed to study the function of BdVIL4 on the development process. The plants with BdVIL4 RNA interferenced (BdVIL4 RNAi plants) had no obvious difference from the wild at 23 °C, but flowered significantly later and had more branches than the control at l6 °C. In BdVIL4 RNAi plants the expression of miR156 were upregulated, and much more at low temperature (l6 °C). Coincidentally, similar to the BdVIL4 RNAi plants, the miR156 overexpressors also showed late flowering and more branches, and the late flowering phynotype just only performanced at lower temperature. The results suggested that BdVIL4 are involved in the regulation of branching and flowering responsing to the ambient temperature by repressing the expression of miR156.