Impact of InMIR319 and light on the expression of InTCP4 gene involved in the development of Ipomoea nil plants

MicroRNAs regulate gene expression by guiding the cleavage or attenuating the translation of target mRNAs. In Arabidopsis thaliana, the subset of class II TCP genes (plant-specific group of transcription factors) contains an miR319-binding site. One of them, AtTCP4, regulates negatively leaf growth and positively leaf senescence. In addition, miR319 targeting of TCP4 is critical for petal and stamen development and affects flowering time. The aim of this work was to identify the cDNA of InTCP4 gene and In-miR319 precursor in Ipomoea nil (Pharbitis nil). The cDNA sequence of InTCP4 shows a significant similarity to the cDNA members of the TCP family of other plant species and contains nucleotides complementary to miR319. The identified sequence In-pre-miR319 creates a long hairpin structure and mature miRNA sequence is located in a similar place as in precursors found in other plant species. Accumulation of InTCP4 mRNA and In-pre-miR319 was examined in various organs of I. nil plants. We found that the InTCP4 is strongly expressed in cotyledons of I. nil seedlings while the In-pre-miR319 accumulates mainly in the hypocotyls of seedlings. Moreover, we investigate the role of InTCP4 in the flowering induction, flower development and cotyledon senescence in I. nil. We indicate that the InTCP4 expression is controlled by both light/clock and miR319. Both InTCP4 and InMIR319 probably participate in the regulation of such processes as do their homologues in other plant species, the development of cotyledons, leaves and flower elements. The main function of InMIR319 seems to be the regulation of InTCP4 organ localization.