Petunia hybrida S-proteins: ribonuclease activity and the role of their glycan side chains in self-incompatibility

Broothaerts, W.; Vanvinckenroye, P.; Decock, Benny; Damme, Jo Van; Vendrig, J. C.

doi:10.1007/bf00200545

Cited by 48 publications

(25 citation statements)

References 39 publications

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“…As bases bioquímicas e genéticas desse sistema têm sido intensamente estudados em Solanaceae (Linskens 1975, Herrero & Dickinson 1979, Broothaerts et al 1991, Golz et al 1995. A presença de auto-incompatibilidade indica que a polinização cruzada deve ser obrigatória para que as populações tenham sucesso reprodutivo.…”

Section: Discussionunclassified

Biologia reprodutiva de Calibrachoa elegans (Miers) Stehmann & Semir (Solanaceae)

Stehmann¹,

Semir²

2001

Rev. bras. Bot.

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-(Reproductive biology of Calibrachoa elegans (Miers) Stehmann & Semir (Solanaceae)). Calibrachoa elegans is an endemic annual species from the "canga" region in the iron quadrangle, Minas Gerais, Brazil. The study of its reproductive biology involved cross-pollination experiments, self-incompatibility tests and observations of the pollination process. Results of manual pollination experiments showed that the studied population is allogamous. Interruption of pollen tube growth in the style of self-pollinated flowers confirmed the occurrence of self-incompatibility reactions. Pollination is effected only by females of Hexantheda missionica (Colletinae, Apoideae), which show high fidelity to flowers of C. elegans; males use the flowers as a nectar source, as stops between flights when searching for females, and as shelter during the night. They prepare the shelter by cutting and removing anthers and style. The populations of Hexantheda missionica found in Minas Gerais are the first records of this species for southeastern Brazil and probably represent remnants that reached this region during the past, but are now disjunct and isolated from those in southern Brazil.RESUMO -(Biologia reprodutiva de Calibrachoa elegans (Miers) Stehmann & Semir (Solanaceae)). Calibrachoa elegans é uma espécie anual, endêmica da região da canga do quadrilátero ferrífero de Minas Gerais, Brasil. O estudo da sua biologia reprodutiva envolveu experimentos de cruzamentos, teste do sistema de auto-incompatibilidade e observação do processo de polinização. Os experimentos realizados através de polinizações manuais indicam que a população estudada é preferencialmente alógama. A interrupção do crescimento do tubo polínico no estilete das flores autopolinizadas, verificada através da microscopia de fluorescência, confirmou a ocorrência de reação de auto-incompatibilidade. A polinização é realizada apenas pelas fêmeas de Hexantheda missionica (Colletinae, Apoideae), uma abelha com alta fidelidade de visita às flores de C. elegans. Os machos desta espécie utilizam as flores como fonte de néctar, como local para pouso entre os vôos de patrulhamento a procura de fêmeas para acasalamento e como abrigo noturno. Para se acomodarem na flor, geralmente cortam e removem os estames e o estilete. As populações de Hexantheda missionica encontradas em Minas Gerais são o primeiro registro da espécie para a região sudeste do Brasil e, provavelmente, representam remanescentes que chegaram a esta região no passado e que agora se encontram disjuntas e isoladas das populações da região sul do Brasil.

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Section: Discussionunclassified

Biologia reprodutiva de Calibrachoa elegans (Miers) Stehmann & Semir (Solanaceae)

Stehmann¹,

Semir²

2001

Rev. bras. Bot.

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“…However, the biochemical nature of S-RNase was not known until several years later when the amino-acid sequence of the fungal RNase T2 was determined (Kawata et al 1988 ) and found to share a signifi cant degree of sequence homology between its catalytic domain and a conserved domain of several allelic variants of S-RNase (McClure et al 1989 ). Subsequently, S-RNase was shown to indeed possess RNase activity in vitro (McClure et al 1989 ;Broothaerts et al 1991 ;Singh et al 1991 ). The S-RNase gene has been shown to be solely responsible for pistil specifi city in SI by gain-and lossof-function experiments Murfett et al 1994 ).…”

Section: Identifi Cation and Characterization Of The S-rnase Genementioning

confidence: 99%

S-RNase-Based Self-Incompatibility in Petunia: A Complex Non-Self Recognition System Between Pollen and Pistil

Sun

Williams

et al. 2014

Sexual Reproduction in Animals and Plants

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Self-incompatibility (SI) is an intraspecifi c reproductive barrier that allows many families of fl owering plants to prevent inbreeding and promote outcrosses. Extensive studies of SI in fi ve families during the past more than two decades have revealed three distinct SI mechanisms. This chapter focuses on the mechanism employed by the Solanaceae, using mostly results obtained from Petunia. We fi rst discuss the identifi cation of two polymorphic genes at the S -locus, the S-RNase gene, which controls pistil specifi city, and the S-locus F-box ( SLF ) gene, now named SLF1 . For several years after its identifi cation, SLF1 was thought to be solely responsible for pollen specifi city, and biochemical models were developed based on this assumption. However, results inconsistent with this assumption were subsequently obtained, which led to the recent fi nding that pollen specifi city is controlled by multiple, but an as yet unknown number of, polymorphic SLF genes located at the S -locus. A new model, named collaborative non-self recognition, has been proposed to explain the biochemical basis of specifi c inhibition of self-pollen tube growth. Based on this model, compatible pollination results from ubiquitination and subsequent degradation of non-self S-RNases collectively mediated by all SLF proteins, with each SLF responsible for detoxifying a subset of non-self S-RNases. We conclude this chapter with a discussion of some of the new questions raised by the fi nding that pollen specifi city is controlled by multiple SLF genes.Keywords Collaborative non-self recognition • Petunia • Self-incompatibility • S -locus F-box proteins • S-RNase IntroductionIn contrast to animals, plants cannot freely move about to select appropriate mates. To preserve species identity and to generate genetic diversity within species, it is imperative that plants possess mechanisms by which their female reproductive tissues, the pistils, can prevent unwanted or unsuitable pollen from delivering sperm cells to the ovary to effect fertilization. For example, many fl owering plants that produce bisexual fl owers have adopted a genetically controlled pre-zygotic barrier, called self-incompatibility (SI). SI involves a self/non-self recognition process between pollen and pistil. As a result of the recognition, self-pollen is rejected by the pistil to prevent inbreeding, and only non-self pollen is accepted to promote outcrosses. The specifi c recognition process involves the interaction between pistil specifi city determinant and pollen specifi city determinant, both of which are encoded by genes tightly linked at a highly polymorphic locus, named the S -locus. Variants of the S -locus are referred to as S -haplotypes and designated S 1 , S 2 , S 3 , etc.SI is quite common in fl owering plants, but to date our understanding of the molecular and biochemical basis is limited to 5 of the estimated more than 60 families that possess SI. Extensive studies on these 5 families since the mid-1980s have revealed three distinct mechanisms (Tak...

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“…Clarke and co-workers subsequently showed that this sequence similarity is not fortuitous, and that N. alata S-proteins indeed had ribonuclease activity (McClure et al, 1989). P. inflata and Petunia hybrida S-proteins were also later examined and found to be ribonucleases (Broothaerts et al, 1991;Singh et al, 1991).…”

Section: Conserved Residues;mentioning

confidence: 99%

Gametophytic Self-Incompatibility: A Mechanism for Self/Nonself Discrimination during Sexual Reproduction

Kao

Huang

1994

Plant Physiol.

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CENETIC BASlS O F SELF-INCOMPATIBILITYVarious mechanisms in flowering plants have evolved to prevent the tendency of self-fertilization created by close proximity of male and female reproductive organs in a perfect flower. One such mechanism, called self-incompatibility (SI), allows the pistil of a plant to reject self pollen or pollen from genetically related individuals, thus preventing inbreeding and promoting outcrosses. Genetic studies camed out early in this century led to the identification of two different types of SI: gametophytic self-incompatibility (GSI) and sporophytic self-incompatibility (SSI). GSI was first studied in the Solanaceae family, and SSI was first studied in the Cruciferae family. To date, these two families still remain the best characterized for their respective SI systems. In both families, SI is controlled by a multiallelic locus termed the S-locus.For GSI, the SI behavior of the pollen is determined by the genotype of the pollen grain itself, whereas for SSI, the SI behavior of the pollen is determined by the genotype of the pollen parent. This difference most likely reflects the difference in the site of expression of the pollen S-allele: microspores for GSI and tapetal tissue for SSI (de Nettancourt, 1977). In the case of SSI, depending on the S-allele combination, the two S-allele specificities displayed by the pollen may be co-dominant or may exhibit other relationships such as dominance or mutual weakening (de Nettancourt, 1977). Figure 1 illustrates the dlfference in the SI behavior of SSI and GSI, assuming co-dominance of S-alleles in the pollen for SSI. Crosses between an S1S2 plant (female) and an s 1 s 3 plant (male) will be compatible if the species displays GSI and will be incompatible if the species displays SSI. The reasons are as follows. In the case of GSI, the SI phenotypes of SI and S3 pollen produced by the S1S3 plant are S1 and S3, respectively. The pollen bearing Sl-allele is rejected by the pistil of the S1S2 plant because of the matching of the S1-allele, whereas the pollen bearing S3-allele, an allele different from those camed by the pistil, is able to effect fertilization to produce SlS3 or S2S3 progeny. The rejection of incompatible pollen usually occurs after the pollen has germinated and Research in the authors' laboratory was supported by grants from the National Science Foundation (DCB-8616087, DCB-8904008, and IBN-9220145) grown into the style. In the case of SSI, both S1 and S3 pollen behave genetically as if they bear both S1-and S3-alleles. Since the S1-allele is also camed by the pistil, neither pollen is able to effect fertilization. The rejection of incompatible pollen usually occurs on the surface of the stigma.Interest in SI largely lies, on the one hand, in its use as a model system to study cell-cell communication, and, on the other hand, in exploring its potential applications in hybrid seed production. Studies prior to 1980 focused mostly on the physiological, cytological, and genetic aspects. A detailed account of the large volume of...

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Petunia hybrida S-proteins: ribonuclease activity and the role of their glycan side chains in self-incompatibility

Cited by 48 publications

References 39 publications

Biologia reprodutiva de Calibrachoa elegans (Miers) Stehmann & Semir (Solanaceae)

Biologia reprodutiva de Calibrachoa elegans (Miers) Stehmann & Semir (Solanaceae)

S-RNase-Based Self-Incompatibility in Petunia: A Complex Non-Self Recognition System Between Pollen and Pistil

Gametophytic Self-Incompatibility: A Mechanism for Self/Nonself Discrimination during Sexual Reproduction

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