TEMPRANILLOhomologs in apple regulate flowering time in the woodland strawberryFragaria vesca

Abstract

AbstractMany economically valuable fruit trees belong to theRosaceaefamily. The long juvenile period of fruit trees makes their breeding costly and time-consuming. Therefore, flowering time regulation and shortening the juvenile phase have been a breeding priority for genetic improvement of fruit tree crops.TEMPRANILLOgenes act as floral inhibitors in Arabidopsis and so, two orthologs of this gene were isolated here from apple (Malus domestica) and functionally analysed in Arabidopsis and woodland strawberry by being overexpressed in both model plants, and partially silenced in strawberry. The overexpression ofMdTEMgenes down-regulatedFvFT1, FvGA3OX1, andFvGA3OX2genes in strawberry. The overexpression lines exhibited delayed flowering, both in terms of days to flowering and the number of leaves at flowering.RNAi-mediatedsilencing ofTEMresulted in early flowering plants. These plants flowered approximately five days earlier than wild type plants with a lower number of leaves. However, the overexpression ofMdTEMgenes could not functionally rescue theArabidopsismutants. According to the results, it can be concluded thatMdTEM1andMdTEM2are orthologs ofFvTEMgene, which play an important role in regulating the juvenile phase and flowering time through controllingFTand GA biosynthetic gene expression.