Isolation of transposable elements from Prunus species and their application for fruit breeding

1997 Fiscal Year Final Research Report Summary

• Project/Area Number: 07660011
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Breeding science
• Research Institution: Osaka City University
• Principal Investigator: UEMATSU Chiyomi Osaka City Univ., Scinece, Assistant Professor, 理学部, 助手 (30232789)
• Project Period (FY): 1995 – 1997
• Keywords: Prunus / Anthocyanin synthetic pathway / Chalcone synthase (CHS) / Chalcone isomerase (CHI) / Flavanone 3-hydroxylase (F3H) / Dihydroflavonol reductase (DFR) / Anthocyanidin synthase (AS) / Transpozable element

Research Abstract

Bud mutation is one of the useful way for fruit breeding although its mechanism is not clear. Selected lines of peach and mume, those are called "Gen-pei-zaki", have two types of branches within one tree. Some branches bear pink colored flowers, others bear white flowers. This phenomenon seems most likely to be caused by the activity of a transposable element. In this project we tried to isolate the transposable element from "Gen-pei-zaki" lines of peach and aimed at clarifying the mechanism of flower color mutation.
When a branch has an intact anthocyanin synthetic pathway, it will bear pink colored flowers. If the transposable element is inserted into a structural gene or a regulatory gene involved in the anthocyanin synthetic pathway, flower color should be white. In order to detect polymorphism of DNAs between two types of branches, non-RI southern blotting system was applied. CHS, CHI, F3H, DFR and AS genes were cloned from the peach by this study and used as a probe. PAL, UFGT, Myb and Myc genes obtained from Antirrhinum majus kindly offered from Dr.Martin were also used as a probe. CHS and DFR gene probes gave different hybridization patterns between branch types. According to hybridization patterns, CHS, CHI, F3H and AS genes were estimated to exist as single or a few copies per haploid genome. On the other hand, the number of PAL and DFR genes were estimated as bigger than them. For the further investigation, genomic library was constructed using pink petals of peach flowers. Structure of six clones obtained from the third screening for DFR genes are now continuously analyzed.
There were only few reports about Prunus species using molecular analysis except for the molecular mapping. This study indicated that molecular techniques were applicable for Prunus species. Further investigation will reveal the difference of CHS and DFR genes between two branch types. Finally transposable element will be isolated and applied for fruit breeding.