Research
| Title： | MicroRNA319-targeted RaTCP1 regulates heterophylly in North American Lake Cress |
|---|---|
| First author： | Li, Gaojie; Hu, Shiqi; Sakamoto, Tomoaki; Ikematsu, Shuka; Yang, Jingjing; Zhao, Xuyao; Schultz, Elizabeth A.; Kimura, Seisuke; Hou, Hongwei |
| Journal： | ENVIRONMENTAL AND EXPERIMENTAL BOTANY |
| Years： | 2025 |
| DOI： | 10.1016/j.envexpbot.2025.106205 |
| Abstract： | Heterophylly, the plasticity of leaf form in response to environmental conditions, widely occurs in aquatic and amphibious plants. Rorippa aquatica produces simple or shallow-serrated leaves in terrestrial conditions but deep dissected leaves under submerged conditions. Regulation of CIN-TCP transcription factors by miR319 controls leaf complexity in several species and here we provide evidence that this regulatory module acts in the heterophylly of R. aquatica. RaTCP1, one of the orthologs of AtTCP4 in R. aquatica, was identified as the most likely target of Raq-miR319b. Under submerged conditions that induced increased leaf complexity, RaTCP1 expression was reduced whereas Raq-miR319b expression was increased. Overexpressing Raq-miR319b in Arabidopsis thaliana reduced TCP gene expression and increased leaf serration. Ectopic expression of RaTCP1 rescued the phenotype of crinkled leaf form in tcp mutants of A. thaliana. The phytohormone abscisic acid (ABA) accumulated in terrestrial leaves of R. aquatica, while it was absent in submerged conditions. We found that the expression of Raq-miR319b can be induced by submergence, while it was repressed by ABA. Our results indicate that the environments regulated heterophylly in R. aquatica occur through the miR319-TCP module. These findings provide novel insights into how the plasticity of leaf shape is established in aquatic plants. |
