Overexpression of Cymbidium goeringii Cgo-miR159 Regulates Anther Dehiscence and Pollen Development in Arabidopsis and Tobacco.

Background: MicroRNA159 (miR159) is a conserved miRNA found in various plant species. By regulating GAMYB-like transcription factors, miR159 is involved in diverse biological processes. Cymbidium goeringii, a significant traditional Chinese orchid, has unique flower shape and elegant fragrance. However, its development has been several limited because of the low flower bud differentiation and the difficult reproduction. This research aims to provide guidance for the role of cgo-miR159 in reproductive organ development to enhance the ornamental and economic value of Cymbidium. Methods: In this study, miR159 was cloned and its expression was determined across different development stages and tissue types. The function of cgo-miR159 was identified using gene transformation in Arabidopsis and tobacco plants. Results: High expression levels of cgo-miR159 were detected in the leaves and stamens during reproductive growth and expression peaked during flower bud development when the flower was above 0.5 to 3 cm in length. In transgenic experiments, the ectopic expression of cgo-miR159 led to defective development in the stamens of model plants (Arabidopsis and tobacco), including earlier anther dehiscence and pollen deformity, which resulted in developmental abnormalities and reduced seeds count in fruits. Conclusions: In summary, cgo-miR159 affected the development of reproductive organs in model plants. This research complements previous studies on the function of miR159 and provide useful references for the genetic improvement of orchids. [ABSTRACT FROM AUTHOR]