FvWRKY50 is an important gene that regulates both vegetative growth and reproductive growth in strawberry

The WRKY transcription factors play important roles in plant growth and resistance,but only a few members have been identified in strawberry.Here we identified a WRKY transcription factor,FvWRKY50,in diploid strawberry which played essential roles in strawberry vegetative growth,and reproductive growth.Knocking out FvWRKY50 by genome editing accelerated flowering time and leaf senescence but delayed anthocyanin accumulation in fruit.Further analysis showed that FvWRKY50 acted as a transcriptional repressor to negatively regulate the expression of flowering-and leaf senescence-related genes,including FvFT2,FvCO,FvFT3,and FvSAUR36.Notably,FvWRKY50 directly upregulated the expression of FvCHI and FvDFR by binding their promoter under normal conditions,but at low temperature FvWRKY50 was phosphorylated by FvMAPK3 and then induced protein degradation by ubiquitination,delaying anthocyanin accumulation.In addition,the homozygous mutant of FvWRKY50 was smaller while the biallelic mutant showed normal size.These new findings provide important clues for us to further reveal the regulatory mechanisms of strawberry growth and fruit ripening.

Removal of the main inflorescence to induce reflowering of loquat

Loquat(Eriobotrya japonica Lindl.)is an evergreen fruit tree species of the Rosaceae,and its unique flowering time greatly hinders its production.To explore the artificial regulation of loquat flowering time,we removed the main inflorescence(by cutting it)to induce reflowering.For different loquat tree cultivars with different stages,the inflorescence was removed by cutting the main floral axis at two alternative positions:the upper or the lower position beneath the inflorescence,and it was found that the proportion of reflowering resulting from removing the upper position of the main floral axis of yellow-flesh loquat cultivars during the full-bloom stage was the highest.In addition,compared with those of the normal-growing panicles,the number of flower buds and branch axes of the reflowering panicles decreased significantly after cutting.Importantly,these newly produced inflorescences flowered 2–4 months later than normal-growing inflorescences did,effectively prolonging both the flowering and fruiting time.In addition,qRT-PCR results showed that EjFT1,EjFT2,EjAP1–1 and EjAP1–2 were highly expressed in the floral axis.These findings highlighted a new method for extending the production cycle of loquat and provided a reference for the flowering regulation of loquat and other economically important fruit tree species.