Study on expression modes and cleavage role of miR156b/c/d and its target gene Vv-SPL9 during the whole growth stage of grapevine

miR156 regulates the expression of its target SPL (PROMOTER BINDING-LIKE) genes during flower and fruit development, diverse developmental stage transitions, especially from vegetative to reproductive growth phases, by cleaving the target mRNA SPL of one plant-specific transcription factor. However, systematic reports on grapevine have yet to be presented. Here, the precise sequence of miR156 (vvi-miR156b/c/d) in grapevine “Takatsuma” was cloned with a previously cloned grapevine SPL (Vv-SPL9). Expression profiles in 18 grapevine tissues were identified through stem-loop RT-PCR. The interaction mode between vvi-miR156b/c/d and Vv-SPL9 was further validated by detecting the cleavage site and cleavage products of 3′- and 5′-ends via an integrated approach of 5′-RLM-RACE (RNA ligase-mediated 5′-rapid amplification of cDNA ends), 3′-PPM-RACE (poly(A) polymerase-mediated 3′-rapid amplification of cDNA ends), and qRT-PCR (real time reverse transcriptase-polymerase chain reaction). The variati...