|Yang, Ching Pa|
|Brown, Charles - Chuck|
Submitted to: American Journal of Potato Research
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2000
Publication Date: 12/15/2000
Citation: CULLEY, D., YANG, C., DEAN, W., BROWN, C.R. CHARACTERIZATION OF THE POLYPHENOL OXIDASE GENE FAMILY FROM THE LOW BROWNING SOLANUM SPECIES, S. HJERTINGII. AMERICAN JOURNAL OF POTATO RESEARCH. 77:396-397. 2000.
Technical Abstract: In an attempt to better understand the mechanism responsible for the low browning trait observed in the tubers of the wild tetraploid species Solanum hjertingii we have cloned and characterized several members of the polyphenol oxidase gene family from this species. Using PCR primers designed to amplify a 1.2 kb region of a known S. tuberosum PPO gene sequence (POT32), a series of PPO related sequences were amplified from S. hjertingii DNA and cloned. The sequences of these clones represented 5 distinct genomic sequences showing varying degrees of homology with known S. tuberosum PPO sequences. One clone in particular (HG9) was interesting because it represented a 0.6 kb PCR band present in all S. hjertingii accessions (and crosses with this species) that expressed the low browning trait. This clone was sequenced and shown to represent a truncated 0.6 kb PPO sequence in which the two copper binding regions required for activity had been deleted. From the sequences of the genomic PCR clones, primers were designed to clone the flanking regions from these loci using inverse PCR. Several clones have been isolated using this strategy, including one that contains the region upstream of the truncated HG9 PPO gene. Comparisons of the S. hjertingii PPO genes with the S. tuberosum genes will be presented, along with data on the transcription of these genes.