Transcriptome analysis identifies differentially expressed genes inducing tuber formation in early-late maturing potato varieties

Potato fruiting time is not only affected by potato ripeness,but also by environmental factors and polygene regulation.How to accurately control the transition of potato fruiting time has important scientific significance and production practical value.At present,the key regulatory factors of this transition are still unclear.In this study,the heterologous early-maturing variety Favorita (F) was used as the scion to graft the late-maturing variety Qingshu 9 (Q),which proved that the heterologous early-maturing scion can induce early potato formation on the late-maturing rootstock.Furthermore,we comprehensively analyzed the transcriptome data of functional leaves and stolons of mutually grafted plants and identified a total of 593 DEGs,of which 38 transcription factor (TFs) genes were included in the DEGs.Based on gene molecular function annotations and existing reports,we speculated that PIF5,bHLH93,CBF3,ERF109,TCP19 and YABBY1 are the key differential genes that induce tuber formation in early and late maturing potato varieties.The YABBY1 gene was selected for functional verification.Compared with the wild type, the leaf area of the StYABBY1 overexpressing plants was smaller and no potato tubercles were formed.The RNAi line had no obvious change in the leaf area and formed tubers.This indicates that StYABBY1 has a biological function in regulating leaf size and tuber formation.