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.

Sequence Diversity in Coding Regions of Candidate Genes in the Glycoalkaloid Biosynthetic Pathway of Wild Potato Species

“…In maize domestication was associated with strong selection of non-transcribed gene regions carrying a regulatory element in teosinte branched1 gene (Wang et al 1999). In HMG2 and SQE the greater sequence variation in introns was caused not only by the number of SNPs but also greater frequency of indels as it was found for an apoplastic invertase inhibitor gene in potato (Datir et al 2012). The lack of regulatory elements in the introns and major constrains on exon region due to pleiotropic effect of these primary metabolism genes could explain greater polymorphism on introns.…”

SNPs in Genes Functional in Starch-Sugar Interconversion Associate with Natural Variation of Tuber Starch and Sugar Content of Potato (Solanum tuberosumL.)

“…The metabolic scheme shown in Figure 1 , however, suggests that this number does not include all important steps in starch biosynthesis and degradation. Furthermore, natural alleles of only few genes functional in starch-sugar interconversion have been characterized at the molecular level ( Datir et al 2012 ; Draffehn et al 2010 , 2012 ; Sowokinos et al 1997 ). DNA variants associated with tuber quality traits were initially discovered based on the analysis of SSCPs ( Dong and Zhu 2005 ), which were highly suitable for de novo discovery of DNA variation in specific loci but not for cost- and labor-effective high-throughput screenings in breeding programs ( Li et al 2005 , 2008 , 2013 ; Urbany et al 2011 ).…”

Cold storage reveals distinct metabolic perturbations in processing and non-processing cultivars of potato

“…5) 455 could be attributed to either the natural allelic variations of genes or changes in transcript levels. 456 Natural variation in candidate genes such as invertase and invertase inhibitors revealed that the 457 genetic polymorphism raises the possibility that SNPs in alleles of these genes may contribute to 458 the phenotypic variation in response to CIS among the potato genotypes (Menéndez et al, 2002;459 Baldwin et al, 2011;Datir et al, 2012;Datir et al, 2019). 460 461 Considerable variation in the levels of citrate and malate were observed in the present investigation 462 ( Fig.…”