Abstract
Background: Fruit abortion is a major limiting factor for fruit production. In flat peach, fruit abortion is present in the whole tree of some accessions during early fruit development. However, the physiological factors and genetic mechanism underlying flat fruit abortion remain largely elusive. Results: In this study, we have revealed that the fertilization process was accomplished and the reduction of sucrose and starch contents might result in flat fruit abortion. By combining association and gene expression analysis, a key candidate gene, PpSnRK1γ, was identified. A 1.67-Mb inversion co-segregated with flat fruit shape altered the promoter activity of PpSnRK1γ, resulting in much lower expression in aborting flat peach. Ectopic transformation in tomato and transient overexpression in peach fruit have shown that PpSnRK1γ could increase sugar and starch contents. Comparative transcriptome analysis further confirmed that PpSnRK1γ participated in carbohydrate metabolism. Subcellular localization found that PpSnRK1γ was located in nucleus. Conclusions: This study clarified the reason for flat fruit abortion and identified a critical candidate gene, PpSnRK1γ, responsible for fruit abortion in peach. The results would provide great help in peach breeding and facilitate gene identification for fruit abortion in other plant species.
Population Structure and Phylogeny of Some U.S. Peach Cultivars
