Functional Analysis of Fvcry1 Reveals the Mechanism of Blue Light in Regulating Vegetative-Reproductive Growth Balance of Strawberry

Abstract

Strawberry is an ideal crop for vertical farming due to its tiny size and high commercial value of fruit. Even though the LED has been widely used as artificial light resource for cultivation of strawberry in vertical farm. The molecular mechanism of blue light spectrums regulating development of strawberry remain to be elucidated. There are two light receptors, including FvCRY1 and FvCRY2, initiate blue light signal in strawberry. To reveal the mechanism of blue light in regulating vegetative-reproductive growth balance of strawberry. We utilized the RNAi method to knock down the expression level of FvCRY1 in wild strawberry (Fragaria vesca ‘Fin56’). The phenotype of RNAi lines comparing the wild type lines was performed. The vegetative growth was significantly promoted displaying an increasing numbers and lengths of stolons in RNAi lines. The B-box transcription factors (BBX) play important roles in light signal transduction and regulation of flowering time. We further analyzed the gene expression of FvBBXs in RNAi lines using qRT-PCR. The FvCO, which has been demonstrated to be a critical regulator in vegetative-reproductive growth balance, was significant repressed in gene expression level. Besides, two new BBX genes, including FvBBX19a and FvBBX28c, were promoted in RNA lines. Collectively, our results shed light on the role of blue light signaling mediated by FvCRY1 in regulating the balance of vegetative-reproductive growth in strawberry.