A new dual-specific incompatibility allele revealed by absence of glycosylation in the conserved C2 site of a Solanum chacoense S-RNase
| Autor: | Jonathan Soulard, Mario Cappadocia, Nicolas Boivin, David Morse, Xike Qin |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
0106 biological sciences
Glycan Glycosylation Solanum chacoense Pollination Physiology Plant Science medicine.disease_cause Solanum 01 natural sciences 03 medical and health sciences chemistry.chemical_compound Ribonucleases Pollen medicine Allele Alleles 030304 developmental biology Genetics 0303 health sciences biology Protein primary structure food and beverages gametophytic self-incompatibility biology.organism_classification Phenotype carbohydrates (lipids) chemistry biology.protein site-directed mutagenesis Allelic recognition S-RNase 010606 plant biology & botany Research Paper |
| Zdroj: | Journal of Experimental Botany |
| ISSN: | 1460-2431 0022-0957 |
| Popis: | The stylar determinant of gametophytic self-incompatibility (GSI) in Solanaceae, Rosaceae, and Plantaginaceae is an S-RNase encoded by a multiallelic S-locus. The primary structure of S-RNases shows five conserved (C) and two hypervariable (HV) regions, the latter forming a domain implicated in S-haplotype-specific recognition of the pollen determinant to SI. All S-RNases are glycosylated at a conserved site in the C2 region, although previous studies have shown that N-linked glycans at this position are not required for S-haplotype-specific recognition and pollen rejection. Here the incompatibility phenotype of three constructs derived from an originally monoglycosylated S11-RNase of Solanum chacoense, that were designed to explore the role of the HV domain in determining pollen recognition and the role of the N-linked glycan in the C2 region, is reported. In one series of experiments, a second glycosylation site was introduced in the HVa region to test for inhibition of pollen-specific recognition. This modification does not impede pollen rejection, although analysis shows incomplete glycosylation at the new site in the HVa region. A second construct, designed to permit complete glycosylation at the HVa site by suppression of the conserved site in the C2 region, did increase the degree of site occupancy, but, again, glycosylation was incomplete. Plants expressing this construct rejected S 11 pollen and, surprisingly, also rejected S 13 pollen, thus displaying an unusual dual specificity phenotype. This construct differs from the first by the absence of the conserved C2 glycosylation site, and thus the dual specificity is observed only in the absence of the C2 glycan. A third construct, completely lacking glycosylation sites, conferred an ability to reject only S 11 pollen, disproving the hypothesis that lack of a conserved glycan would confer a universal pollen rejection phenotype to the plant. |
| Databáze: | OpenAIRE |
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