Ectopic expression of FvVND4c promotes secondary cell wall thickening and flavonoid accumulation in Fragaria vesca

Secondary cell wall thickening (SCW) has a significant effect in the growth and development of plants, as well as in the resistance to various biotic and abiotic stresses. It is regulated by a multilevel transcriptional regulatory network, in which VASCULAR-RELATED NAC-DOMAINs (VNDs) act as key regulators. Lignin is an important component of SCW, it has a cooperative regulation with the biosynthesis of flavonoids which also originate from phenylpropanoid pathway. However, there are few studies on SCW thickening and flavonoid biosynthesis in flesh fruits. We want to investigate the role of FvVNDs on cell wall and fruit color development in Fragaria vesca. We characterized three VNDs in Fragaria vesca , and transient overexpression of FvVND4c and its candidate downstream factor FvMYB46 induced SCW thickening in diploid strawberry fruits . We then performed transcriptome analysis of FvVND4c and FvMYB46 overexpressed plants to investigate which metabolic pathways they are involved in.