title: Allele diversity for the apoplastic invertase inhibitor gene from potato.
abstract: In planta the enzymatic activity of apoplastic and vacuolar invertases is controlled by inhibitory proteins. Although these invertase inhibitors (apoplastic and vacuolar forms) have been implicated as contributing to resistance to cold-induced sweetening (CIS) in tubers of potato (Solanum tuberosum L.), there is a lack of information on the structure and allelic diversity of the apoplastic invertase inhibitor genes. We have PCR-isolated and sequenced the alleles of the apoplastic invertase inhibitor gene (Stinh1) from three tetraploid potato genotypes: 1021/1 (a genotype with very high tolerance to CIS), 'Karaka' and 'Summer Delight' (two cultivars that are highly susceptible to CIS). In total, five alleles were identified in these genotypes, of which four (Stinh1-c, Stinh1-d, Stinh1-e, Stinh1-f) were novel. An analysis of allele diversity was conducted by incorporating previously published sequences of apoplastic invertase inhibitors from potato. Eight alleles were assessed for sequence polymorphism in the two exons and the single hypervariable intron. Contrary to the hypervariable intron, only 65 single nucleotide polymorphisms were observed in the exons, of which 42 confer amino acid substitutions. Phylogenetic analysis of amino acid sequences indicates that the alleles of the invertase inhibitor are highly conserved amongst members of the Solanaceae family.
authors.affiliation: The New Zealand Institute for Plant & Food Research Limited, Private Bag 4704, Christchurch 8140, New Zealand.
authors.forename: Sagar S
authors.initials: SS
authors.lastname: Datir
authors.forename: Julie M
authors.initials: JM
authors.lastname: Latimer
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Thomson
authors.forename: Hayley J
authors.initials: HJ
authors.lastname: Ridgway
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Conner
authors.forename: Jeanne M E
authors.initials: JM
authors.lastname: Jacobs
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D003080:Cold Temperature; D018744:DNA, Plant / Q000235:genetics; D005091:Exons; D017343:Genes, Plant; D014644:Genetic Variation; D007438:Introns; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000235:genetics* / Q000378:metabolism; D057891:Tetraploidy; D043324:beta-Fructofuranosidase / Q000037:antagonists & inhibitors
chemical_list: D018744:DNA, Plant; D010940:Plant Proteins; D043324:beta-Fructofuranosidase