The mobile RNAs, StBEL11 and StBEL29, suppress growth of tubers in potato

Key message We demonstrate that RNAs of StBEL11 and StBEL29 are phloem-mobile and function antagonistically to the growth-promoting characteristics of StBEL5 in potato. Both these RNAs appear to inhibit tuber growth by repressing the activity of target genes of StBEL5 in potato. Moreover, upstream sequence driving GUS expression in transgenic potato lines demonstrated that both StBEL11 and -29 promoter activity is robust in leaf veins, petioles, stems, and vascular tissues and induced by short days in leaves and stolons. Steady-state levels of their mRNAs were also enhanced by short-day conditions in selective organs.