Poster: Genomics Resources

Abs # 938: Functional characterization of genes possibly related to storage root induction in sweetpotato

Presenter:	Bae, Jung-Myung , jmbae@korea.ac.kr
Authors	Bae, Jung-Myung  (A)   Ahn, Young Sup  (B)   Shin, Jeong Sheop  (A)
Affiliations:	(A): Graduate School of Biotechnology, Korea University (B): Mokpo Experiment Station, National Honam Agricultural Experiment Station, RDA

Previously, genes possibly related to initiation of storage root development in sweetpotato were identified from early stage storage roots (0.3 – 1 cm in diameter). Single-pass sequences of the 5’ ends of 2,859 sweetpotato cDNA clones were assembled into 483 clusters and 442 singletons. Comparison of sweetpotato ESTs to nodulation/tumorigenesis-related sequence databases (nodule-, tumor-, potato tuber- and development-related sequences) revealed that homologues of 39 sweetpotato EST sequences potentially involved in gene regulation, signal transduction and development were present in at least one of the nodulation/tumorigenesis-related sequence databases. Northern blot analyses of these 39 sequences identified 22 differentially expressed genes in early stage storage root and fibrous root. Transcription levels of seven sweetpotato genes were elevated in early stage storage root. Transcription levels of ten sweetpotato genes were decreased in early stage storage root. Transcription of five sweetpotato genes was elevated in fibrous root of non-storage root stage. Transcription of J-8 like protein , early nodulin 93 (ENOD93) and tumor protein genes was elevated in early stage storage root. To further identify the functional roles of those genes, full-length cDNAs of putative J-8 like protein, tumor protein and ENOD93 were overexpressed in Arabidopsis thaliana. Phenotypic changes in root morphology of transgenic Arabidopsis were studied.