Identification and characterization of the miR396f-GRF10 module in phase transition of Lilium

Lilium species are widely used in horticulture for cut flowers and decorations as well as in traditional medicine for their ornamental, edible, and medicinal value. Although it is commonly known that variable temperature treatment could accelerate Lilium development from vegetative to reproductive growth, little is known about the molecular mechanisms of its development. Here, the key module miR396f-GRF10 was selected based on bioinformatics analysis, and transgenic function verification was conducted, which showed that overexpression of Lbr-miR396f inhibited the phase transition. In contrast, overexpression of LbrGRF10 promoted this process. In addition, through subcellular localization and bimolecular fluorescence complementation, the interaction of LbrGRF10 with LbrGIF1 and LbrGIF2 and its localization in the nucleus were confirmed. Results from in situ hybridization experiments revealed that after alternating temperature treatment, in the variable temperature treatment group, the hybridization signal exhibited higher expression levels in the apical growth cone, young leaves, and shoot axes, indicating a significant up-regulation of LbrGRF10 expression. This study provides new perspectives and ideas for revealing the molecular mechanisms of phase transition in Lilium.