scholarly journals A Molecular Description of Mutations Affecting the Pollen Component of the Nicotiana alata S locus

Genetics ◽  
1999 ◽  
Vol 152 (3) ◽  
pp. 1123-1135 ◽  
Author(s):  
J F Golz ◽  
V Su ◽  
A E Clarke ◽  
E Newbigin
Keyword(s):  
Extra Chromosome ◽  
Nicotiana Alata ◽  
Self Incompatibility ◽  
S Locus ◽  
Cytological Examination ◽  
Mutagenesis Screen ◽  
Genes Encoding ◽  
Additional Chromosome ◽  
S Allele ◽  
Molecular Description

Abstract Mutations affecting the self-incompatibility response of Nicotiana alata were generated by irradiation. Mutants in the M1 generation were selected on the basis of pollen tube growth through an otherwise incompatible pistil. Twelve of the 18 M1 plants obtained from the mutagenesis screen were self-compatible. Eleven self-compatible plants had mutations affecting only the pollen function of the S locus (pollen-part mutants). The remaining self-compatible plant had a mutation affecting only the style function of the S locus (style-part mutant). Cytological examination of the pollen-part mutant plants revealed that 8 had an extra chromosome (2n + 1) and 3 did not. The pollen-part mutation in 7 M1 plants was followed in a series of crosses. DNA blot analysis using probes for S-RNase genes (encoding the style function of the S locus) indicated that the pollen-part mutation was associated with an extra S allele in 4 M1 plants. In 3 of these plants, the extra S allele was located on the additional chromosome. There was no evidence of an extra S allele in the 3 remaining M1 plants. The breakdown of self-incompatibility in plants with an extra S allele is discussed with reference to current models of the molecular basis of self-incompatibility.

scholarly journals The Turnera Style S-Locus Gene TsBAHD Possesses Brassinosteroid-Inactivating Activity When Expressed in Arabidopsis thaliana

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1566
Author(s):  
Courtney M. Matzke ◽  
Joel S. Shore ◽  
Michael M. Neff ◽  
Andrew G. McCubbin
Keyword(s):  
Arabidopsis Thaliana ◽  
Empirical Support ◽  
Self Incompatibility ◽  
S Locus ◽  
Style Length ◽  
Hypocotyl Growth ◽  
Genes Encoding ◽  
Endogenous Genes ◽  
Self Fertilization ◽  
Floral Form

Heterostyly distinct hermaphroditic floral morphs enforce outbreeding. Morphs differ structurally, promote cross-pollination, and physiologically block self-fertilization. In Turnera the self-incompatibility (S)-locus controlling heterostyly possesses three genes specific to short-styled morph genomes. Only one gene, TsBAHD, is expressed in pistils and this has been hypothesized to possess brassinosteroid (BR)-inactivating activity. We tested this hypothesis using heterologous expression in Arabidopsis thaliana as a bioassay, thereby assessing growth phenotype, and the impacts on the expression of endogenous genes involved in BR homeostasis and seedling photomorphogenesis. Transgenic A. thaliana expressing TsBAHD displayed phenotypes typical of BR-deficient mutants, with phenotype severity dependent on TsBAHD expression level. BAS1, which encodes an enzyme involved in BR inactivation, was downregulated in TsBAHD-expressing lines. CPD and DWF, which encode enzymes involved in BR biosynthesis, were upregulated. Hypocotyl growth of TsBAHD dwarfs responded to application of brassinolide in light and dark in a manner typical of plants over-expressing genes encoding BR-inactivating activity. These results provide empirical support for the hypothesis that TsBAHD possesses BR-inactivating activity. Further this suggests that style length in Turnera is controlled by the same mechanism (BR inactivation) as that reported for Primula, but using a different class of enzyme. This reveals interesting convergent evolution in a biochemical mechanism to regulate floral form in heterostyly.

scholarly journals Self-incompatibility alleles in Esatern European and Asian almond (Prunus dulcis) genotypes: a preliminary study

2012 ◽  
Vol 18 (2) ◽  
Author(s):  
B. Szikriszt ◽  
S. Ercisli ◽  
A. Hegedűs ◽  
J. Halász
Keyword(s):  
Prunus Dulcis ◽  
Natural Occurrence ◽  
Eastern European ◽  
Self Incompatibility ◽  
S Locus ◽  
Centre Of Origin ◽  
Incompatibility Alleles ◽  
S Allele ◽  
The Village ◽  
New Alleles

Almond [Prunus dulcis (Mill.) D. A. Webb.] as one of the oldest domesticated plants is thought to have originated in central Asia. Gametophytic self-incompatibility of almond is controlled by the highly polymorphic S-locus. The S-locus encodes for an S-ribonuclease (S-RNase) protein in the pistils, which degrades RNA in self-pollen tubes and hence stops their growing. This study was carried out to detect S-RNase allelic variants in Hungarian and Eastern European almond cultivars and Turkish wild growing seedlings, and characterize their S-allele pool. Five new alleles were identifi ed, S31H, S36-S39 in Eastern European local cultivars. The village Bademli and Akdamar island are two distinct places of almond natural occurrence in Turkey. Trees growing wild around Bademli city showed greater genetic diversity than those originated on Akdamar island. Many of the previously described 45 S-RNase alleles have been also detected in these regions. Homology searches revealed that Turkish almonds carried some P. webbii alleles indicating hybridization between the two cultivars and massive introgression events. Our results supply long-awaited information on almond S-allele diversity from regions between the main cultivation centres and the centre of origin of this species; and are discussed from the aspect of methodological developments and evolution of the cultivated almond.

Latent S alleles are widespread in cultivated self-compatible Brassica napus

Genome ◽  
2004 ◽  
Vol 47 (2) ◽  
pp. 257-265 ◽  
Author(s):  
U U Ekuere ◽  
I A.P Parkin ◽  
C Bowman ◽  
D Marshall ◽  
D J Lydiate
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Self Incompatibility ◽  
S Locus ◽  
Winter Oilseed Rape ◽  
A Genome ◽  
C Genome ◽  
S Alleles ◽  
Crop Types ◽  
S Allele

The genetic control of self-incompatibility in Brassica napus was investigated using crosses between resynthesized lines of B. napus and cultivars of oilseed rape. These crosses introduced eight C-genome S alleles from Brassica oleracea (S16, S22, S23, S25, S29, S35, S60, and S63) and one A-genome S allele from Brassica rapa (SRM29) into winter oilseed rape. The inheritance of S alleles was monitored using genetic markers and S phenotypes were determined in the F1, F2, first backcross (B1), and testcross (T1) generations. Two different F1 hybrids were used to develop populations of doubled haploid lines that were subjected to genetic mapping and scored for S phenotype. These investigations identified a latent S allele in at least two oilseed rape cultivars and indicated that the S phenotype of these latent alleles was masked by a suppressor system common to oilseed rape. These latent S alleles may be widespread in oilseed rape varieties and are possibly associated with the highly conserved C-genome S locus of these crop types. Segregation for S phenotype in subpopulations uniform for S genotype suggests the existence of suppressor loci that influenced the expression of the S phenotype. These suppressor loci were not linked to the S loci and possessed suppressing alleles in oilseed rape and non-suppressing alleles in the diploid parents of resynthesized B. napus lines.Key words: self-incompatibility, B. oleracea, B. rapa, S locus, suppression.

scholarly journals S-RNase Alleles Associated With Self-Compatibility in the Tomato Clade: Structure, Origins, and Expression Plasticity

2021 ◽  
Vol 12 ◽  
Author(s):  
Amanda K. Broz ◽  
Christopher M. Miller ◽  
You Soon Baek ◽  
Alejandro Tovar-Méndez ◽  
Pablo Geovanny Acosta-Quezada ◽  
...  
Keyword(s):  
Natural Populations ◽  
Reproductive Barriers ◽  
Self Incompatibility ◽  
S Locus ◽  
Loss Of Function ◽  
Resistance Factors ◽  
Tomato Species ◽  
Genes Encoding ◽  
Self Compatibility ◽  
Barrier Resistance

The self-incompatibility (SI) system in the Solanaceae is comprised of cytotoxic pistil S-RNases which are countered by S-locus F-box (SLF) resistance factors found in pollen. Under this barrier-resistance architecture, mating system transitions from SI to self-compatibility (SC) typically result from loss-of-function mutations in genes encoding pistil SI factors such as S-RNase. However, the nature of these mutations is often not well characterized. Here we use a combination of S-RNase sequence analysis, transcript profiling, protein expression and reproductive phenotyping to better understand different mechanisms that result in loss of S-RNase function. Our analysis focuses on 12 S-RNase alleles identified in SC species and populations across the tomato clade. In six cases, the reason for gene dysfunction due to mutations is evident. The six other alleles potentially encode functional S-RNase proteins but are typically transcriptionally silenced. We identified three S-RNase alleles which are transcriptionally silenced under some conditions but actively expressed in others. In one case, expression of the S-RNase is associated with SI. In another case, S-RNase expression does not lead to SI, but instead confers a reproductive barrier against pollen tubes from other tomato species. In the third case, expression of S-RNase does not affect self, interspecific or inter-population reproductive barriers. Our results indicate that S-RNase expression is more dynamic than previously thought, and that changes in expression can impact different reproductive barriers within or between natural populations.

scholarly journals PERICLINAL CHIMERAS COMPOSED OF LYCOPERSICON PERUVIANUM AND L. ESCULENTUM DEMONSTRATE THAT S-LOCUS ASSOCIATED PROTEINS AND SELF-INCOMPATIBILITY CAN BE UNCOUPLED

HortScience ◽  
1995 ◽  
Vol 30 (2) ◽  
pp. 193b-193
Author(s):  
Bindu Chawla ◽  
Robert Bernatzki ◽  
Michael Marcotrigiano
Keyword(s):  
Fruit Set ◽  
Self Incompatibility ◽  
Lycopersicon Peruvianum ◽  
S Locus ◽  
Rna Analysis ◽  
Sds Page ◽  
Associated Proteins ◽  
Periclinal Chimeras ◽  
S Allele ◽  
L1 And L2

Lycopersicon peruvianum is a wild species of tomato that exhibits gametophytic self-incompatibility (S), wherein the SI response is controlled by the genotype of the pollen. Cultivated tomato (L. esculentum) is a self-compatible species. Assisted by phenotypic markers, periclinal graft chimeras between these two species have been obtained. Fruit set analysis following breeding demonstrated that the available five chimeras (PPE, PEE, PEP, EPP, and EEP) are able to accept pollen from L. peruvianum, suggesting that there is a failure of the SI response. SI response is known to be dependent on S-locus associated proteins. These proteins are present in the style, which is mainly derived from the L1 and L2 layers of meristem. RNA analysis of the style tissue using a cloned S-locus cDNA as a probe showed that, except for EEP, all chimeras expressed the S-allele. This was also confirmed by SDS-PAGE analysis of stylar proteins that were present in variable amounts depending on the periclinal combination. Thus, the breakdown of SI is not associated with the lack of expression of the S-locus. Further work is being conducted to understand the nature of this breakdown.

scholarly journals Molecular S-genotyping of sweet cherry (Prunus avium L.) genetic resources

2019 ◽  
Vol 46 (No. 3) ◽  
pp. 146-152
Author(s):  
Josef Patzak ◽  
Alena Henychová ◽  
František Paprštein ◽  
Jiří Sedlák
Keyword(s):  
Genetic Resources ◽  
Sweet Cherry ◽  
Prunus Avium ◽  
Self Incompatibility ◽  
S Locus ◽  
Specific Pcr ◽  
Sweet Cherries ◽  
Allele Specific ◽  
S Allele ◽  
Specific Pcr Primer

Sweet cherries are self-incompatible, which is determined by a gametophytic self-incompatibility system (GSI). The self-incompatibility is controlled by a multi-allelic S-locus. Knowledge about the S-allele constitution of the cultivars is essential for fruit growers and breeders. Recently, molecular PCR-based methods have been developed to distinguish all S-alleles in sweet cherries. In our work, we analysed S-locus genotypes by 13 universal and allele-specific PCR primer combinations within 117 registered, old and local sweet cherry cultivars from the Czech genetic resources of the Research and Breeding Institute of Pomology in Holovousy, the Czech Republic. We confirmed the previous S-genotyping for 66 accessions except for Drogans Gelbe, Hedelfinger, Erika, Meckenheimer Frühe, Badeborner, Bing, Alfa, Gamma, Huldra, Rivan, Valerij Tschkalov, Viola and Winkler’s Frühe. It could be due to either mislabelling or mistakes in the previous analyses. Newly, S-genotyping was determined for 51 accessions in which we found 4 new S-loci combinations. We detected the S-locus combinations in 19 incompatibility groups. The most frequent incompatibility groups were III (S<sub>3</sub>S<sub>4</sub>), II (S<sub>1</sub>S<sub>3</sub>), IV (S<sub>2</sub>S<sub>3</sub>), and VI (S<sub>3</sub>S<sub>6</sub>) with 22, 20, 12 and 12 genotypes, respectively.  

Segregation Distortion of T-DNA Markers Linked to the Self-Incompatibility (S) Locus in Petunia hybrida

Genetics ◽  
2000 ◽  
Vol 154 (3) ◽  
pp. 1323-1333
Author(s):  
Robin M Harbord ◽  
Carolyn A Napoli ◽  
Timothy P Robbins
Keyword(s):  
Segregation Distortion ◽  
Petunia Hybrida ◽  
Selectable Marker ◽  
The Self ◽  
Self Incompatibility ◽  
S Locus ◽  
Differential Transmission ◽  
S Allele ◽  
Maize Transposable Element ◽  
General Method

Abstract In plants with a gametophytic self-incompatibility system the specificity of the pollen is determined by the haploid genotype at the self-incompatibility (S) locus. In certain crosses this can lead to the exclusion of half the gametes from the male parent carrying a particular S-allele. This leads to pronounced segregation distortion for any genetic markers that are linked to the S-locus. We have used this approach to identify T-DNA insertions carrying a maize transposable element that are linked to the S-locus of Petunia hybrida. A total of 83 T-DNA insertions were tested for segregation distortion of the selectable marker used during transformation with Agrobacterium. Segregation distortion was observed for 12 T-DNA insertions and at least 8 of these were shown to be in the same linkage group by intercrossing. This indicates that differential transmission of a single locus (S) is probably responsible for all of these examples of T-DNA segregation distortion. The identification of selectable markers in coupling with a functional S-allele will allow the preselection of recombination events around the S-locus in petunia. Our approach provides a general method for identifying transgenes that are linked to gametophytic self-incompatibility loci and provides an opportunity for transposon tagging of the petunia S-locus.

scholarly journals S-RNase proteins: functional studies of the 120kDa glycoprotein and SRNase oligomerization

2005 ◽  
Author(s):  
◽  
Charles Nathan Hancock
Keyword(s):  
Nicotiana Alata ◽  
Self Incompatibility ◽  
S Locus ◽  
Transmitting Tract ◽  
Functional Studies ◽  
S Haplotype ◽  
S Factor ◽  
Self Association ◽  
Incompatible Cross ◽  
F Box Protein

Flowering plants control fertilization through pollen-pistil interactions. Self-incompatibility (SI) is a well-studied pollen-pistil interaction that promotes cross-pollination. SI is controlled by a multi-haplotype locus called the S-locus. In Nicotiana alata, S-RNase is a product of the S-locus and regulates specificity in the pistil, while S-locus F-box protein (SLF) controls specificity in the pollen. The interaction between S-RNase and SLF determines whether the pollination is compatible or incompatible. In an incompatible cross, the ribonuclease activity of S-RNase inhibits pollen tube growth. Genetic experiments indicate that, in addition to S-RNase and SLF, non-S-factors are also required for SI. S-RNase binding proteins represent potential non-S-factors required for SI. Using affinity chromatography, we found that S-RNase selfassociates and three homologous stylar glycoproteins - the 120kDa glycoprotein (120K), N. alata pistil extensin-like protein III (NaPELP III), and N. alata transmitting tract specific glycoprotein (NaTTS) - bind directly to S-RNase. I studied the oligomerization of S-RNase in detail and found that self-association is dependent on S-haplotype and buffer conditions. I determined that the components of the S-RNase complex account for 30% of soluble pistil protein. 120K is the most likely candidate for a non-S-factor because it enters the cytoplasm of growing pollen tubes and shows polymorphism when SI and self-compatible Nicotiana species are compared. To test its role in SI, I suppressed 120K expression using RNAi. Suppressing 120K caused a breakdown of SI, confirming that it functions in SI.

scholarly journals Genotyping Hungarian apricot cultivars for self-(in)compatibility by isoelectric focusing and PCR analysis

2005 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Pedryc ◽  
J. Halász ◽  
R. Hermán ◽  
A. Hegedűs
Keyword(s):  
Isoelectric Focusing ◽  
Genetic System ◽  
Pcr Analysis ◽  
Self Incompatibility ◽  
S Locus ◽  
Prunus Species ◽  
First Intron ◽  
S Alleles ◽  
S Allele ◽  
Consensus Primers

Self-incompatibility (SI) in flowering plants is a widespread genetic system that promotes out-crossing. In Prunus species the SI is a gametophytic trait, which is controlled by a single multiallelic locus, termed S-locus. S-alleles codify stylar glycoproteins with ribonuclease activity (S-RNases). Our objective was to assess the S-genotype of some Hungarian apricot varieties by isoelectric focusing of stylar RNases as well as by PCR analysis using cherry consensus primers. Consensus primers amplified one or two bands of various sizes. Primers amplifying the 1st intron gained fragments the size of which ranged from 250 to 500 bp; while those amplifying the 2nd intron resulted in fragments of 800-2000 by length. Our data demonstrated that the first intron of the apricot S-RNase gene is shorter than the second one, which coincides with the structure of cherry S-RNase alleles. `Hargrand' (S1S2) and `Harcoe (S1S4) possessed one common S-RNase isoenzyme. Hungarian 'Orias' apricot cultivars showed different bands compared to the previous cultivars, but they shared completely identical patterns confirming that they possess the same S-genotype. 'Bergeron', `Harmat' and 'Korai zamatos' are characterised by an evidently distinct S-RNase pattern. The self-compatible cultivar (`Bergeron') had one allele, which suggests its correspondence to the Sc. Primers for the 2nd intron was unsuccessful in gaining fragments, which indicates that the 2nd intron in the Sc allele is too long to get any amplification. On the basis of our data, identities and differences were revealed in the S-allele constitution of some economically important Hungarian apricot cultivars at protein and DNA levels.

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