A transcriptional network that controls strawberry fruit ripening

Xiaojing Li and Guozheng Qin, Institute of Botany, Chinese Academy of Sciences

Background: Strawberry is an important horticultural crop with a high economic value worldwide. Various factors regulate the ripening of strawberry fruit, including the plant hormone abscisic acid (ABA), epigenetic modifications, and transcription factors. In a previous study, the transcription factor Ripening Inducing Factor (RIF) was reported to be necessary for the ripening of strawberry fruit, but the regulatory network mediated by RIF remains unclear.

Question: What are the direct target genes of RIF in strawberry? How is the transcriptional activity of RIF modulated?

Findings: We found that RIF in diploid strawberry (Fragraria vesca, FvRIF) functions as a key regulator in controlling fruit ripening, and loss of function of FvRIF leads to a complete blockage of the ripening process. DNA affinity purification sequencing coupled with RNA sequencing identified 2080 genes as potential direct targets of FvRIF, including genes involved in anthocyanin biosynthesis, cell wall degradation, and sugar metabolism. We demonstrate that FvRIF regulates various aspects of fruit ripening by directly modulating core sets of genes involved in these processes. Furthermore, we show that FvRIF physically interacts with the kinase FvMAPK6, which phosphorylates and regulates FvRIF activity.

Next steps: We next wish to identify the transcription factors that directly bind to the promoter of FvRIF and regulate its expression. Moreover, our work suggests a number of transcription factors as the targets of FvRIF. It will be interesting to explore their function in the regulation of strawberry fruit ripening.


Xiaojing Li, Carmen Martín-Pizarro, Leilei Zhou, Bingzhu Hou, Yuying Wang, Yuanyue Shen, Bingbing Li, David Posé, Guozheng Qin (2023) Deciphering the regulatory network of the NAC transcription factor FvRIF, a key regulator of strawberry (Fragaria vesca) fruit ripening. https://doi.org/10.1093/plcell/koad210