1
|
Wu J, Nan X, Zhang X, Xu W, Ma H, Yang Z, Wang C. The Identification and Analysis of the Self-Incompatibility Pollen Determinant Factor SLF in Lycium barbarum. PLANTS (BASEL, SWITZERLAND) 2024; 13:959. [PMID: 38611487 PMCID: PMC11013074 DOI: 10.3390/plants13070959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/07/2024] [Accepted: 03/22/2024] [Indexed: 04/14/2024]
Abstract
Self-incompatibility is a widespread genetic mechanism found in flowering plants. It plays a crucial role in preventing inbreeding and promoting outcrossing. The genes that control self-incompatibility in plants are typically determined by the S-locus female determinant factor and the S-locus male determinant factor. In the Solanaceae family, the male determinant factor is often the SLF gene. In this research, we cloned and analyzed 13 S2-LbSLF genes from the L. barbarum genome, which are located on chromosome 2 and close to the physical location of the S-locus female determinant factor S-RNase, covering a region of approximately 90.4 Mb. The amino acid sequence identity of the 13 S2-LbSLFs is 58.46%, and they all possess relatively conserved motifs and typical F-box domains, without introns. A co-linearity analysis revealed that there are no tandemly repeated genes in the S2-LbSLF genes, and that there are two pairs of co-linear genes between S2-LbSLF and the tomato, which also belongs to the Solanaceae family. A phylogenetic analysis indicates that the S2-LbSLF members can be divided into six groups, and it was found that the 13 S2-LbSLFs are clustered with the SLF genes of tobacco and Petunia inflata to varying degrees, potentially serving as pollen determinant factors regulating self-incompatibility in L. barbarum. The results for the gene expression patterns suggest that S2-LbSLF is only expressed in pollen tissue. The results of the yeast two-hybrid assay showed that the C-terminal region of S2-LbSLFs lacking the F-box domain can interact with S-RNase. This study provides theoretical data for further investigation into the functions of S2-LbSLF members, particularly for the identification of pollen determinant factors regulating self-incompatibility in L. barbarum.
Collapse
Affiliation(s)
- Jiali Wu
- School of Biological Science and Engineering, North Minzu University, Yinchuan 750021, China
| | - Xiongxiong Nan
- State Key Laboratory of Efficient Production of Forest Resources, Yinchuan 750004, China
| | - Xin Zhang
- School of Biological Science and Engineering, North Minzu University, Yinchuan 750021, China
- Innovation Team for Genetic Improvement of Economic Forests, North Minzu University, Yinchuan 750021, China
| | - Wendi Xu
- School of Biological Science and Engineering, North Minzu University, Yinchuan 750021, China
- Innovation Team for Genetic Improvement of Economic Forests, North Minzu University, Yinchuan 750021, China
| | - Haijun Ma
- School of Biological Science and Engineering, North Minzu University, Yinchuan 750021, China
- Ningxia Grape and Wine Innovation Center, North Minzu University, Yinchuan 750021, China
| | - Zijun Yang
- School of Biological Science and Engineering, North Minzu University, Yinchuan 750021, China
| | - Cuiping Wang
- School of Biological Science and Engineering, North Minzu University, Yinchuan 750021, China
- Innovation Team for Genetic Improvement of Economic Forests, North Minzu University, Yinchuan 750021, China
| |
Collapse
|
2
|
Cornille A, Antolín F, Garcia E, Vernesi C, Fietta A, Brinkkemper O, Kirleis W, Schlumbaum A, Roldán-Ruiz I. A Multifaceted Overview of Apple Tree Domestication. TRENDS IN PLANT SCIENCE 2019; 24:770-782. [PMID: 31296442 DOI: 10.1016/j.tplants.2019.05.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 05/15/2019] [Accepted: 05/20/2019] [Indexed: 05/19/2023]
Abstract
The apple is an iconic tree and a major fruit crop worldwide. It is also a model species for the study of the evolutionary processes and genomic basis underlying the domestication of clonally propagated perennial crops. Multidisciplinary approaches from across Eurasia have documented the pace and process of cultivation of this remarkable crop. While population genetics and genomics have revealed the overall domestication history of apple across Eurasia, untangling the evolutionary processes involved, archeobotany has helped to document the transition from gathering and using apples to the practice of cultivation. Further studies integrating archeogenetic and archeogenomic approaches will bring new insights about key traits involved in apple domestication. Such knowledge has potential to boost innovation in present-day apple breeding.
Collapse
Affiliation(s)
- Amandine Cornille
- Génétique Quantitative et Evolution- Le Moulon, INRA, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Gif-sur-Yvette, France.
| | - Ferran Antolín
- Integrative Prehistory and Archeological Science (IPNA/IPAS), Department of Environmental Sciences, University of Basel, Spalenring 145, 4055 Basel, Switzerland
| | - Elena Garcia
- Department of Horticulture, University of Arkansas, Fayetteville, AR, USA
| | - Cristiano Vernesi
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre - Fondazione Edmund Mach, via Edmund Mach 1, 38010 San Michele all'Adige, TN, Italy
| | - Alice Fietta
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre - Fondazione Edmund Mach, via Edmund Mach 1, 38010 San Michele all'Adige, TN, Italy
| | - Otto Brinkkemper
- Cultural Heritage Agency, PO Box 1600, 3800 BP Amersfoort, The Netherlands
| | - Wiebke Kirleis
- Institute for Prehistoric and Protohistoric Archeology/Graduate School Human Development in Landscapes, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Angela Schlumbaum
- Integrative Prehistory and Archeological Science (IPNA/IPAS), Department of Environmental Sciences, University of Basel, Spalenring 145, 4055 Basel, Switzerland
| | - Isabel Roldán-Ruiz
- Flanders Research Institute for Agriculture, Fisheries, and Food (ILVO), Plant Sciences Unit, Caritasstraat 39, 9090 Melle, Belgium; Ghent University, Faculty of Sciences, Department of Plant Biotechnology and Bioinformatics, Technologiepark 71, 9052 Ghent, Belgium
| |
Collapse
|
3
|
De Franceschi P, Bianco L, Cestaro A, Dondini L, Velasco R. Characterization of 25 full-length S-RNase alleles, including flanking regions, from a pool of resequenced apple cultivars. PLANT MOLECULAR BIOLOGY 2018; 97:279-296. [PMID: 29845556 DOI: 10.1007/s11103-018-0741-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 05/17/2018] [Indexed: 05/07/2023]
Abstract
Data obtained from Illumina resequencing of 63 apple cultivars were used to obtain full-length S-RNase sequences using a strategy based on both alignment and de novo assembly of reads. The reproductive biology of apple is regulated by the S-RNase-based gametophytic self-incompatibility system, that is genetically controlled by the single, multi-genic and multi-allelic S locus. Resequencing of apple cultivars provided a huge amount of genetic data, that can be aligned to the reference genome in order to characterize variation to a genome-wide level. However, this approach is not immediately adaptable to the S-locus, due to some peculiar features such as the high degree of polymorphism, lack of colinearity between haplotypes and extensive presence of repetitive elements. In this study we describe a dedicated procedure aimed at characterizing S-RNase alleles from resequenced cultivars. The S-genotype of 63 apple accessions is reported; the full length coding sequence was determined for the 25 S-RNase alleles present in the 63 resequenced cultivars; these included 10 previously incomplete sequences (S 5 , S 6a , S 6b , S 8 , S 11 , S 23 , S 39 , S 46 , S 50 and S 58 ). Moreover, sequence divergence clearly suggests that alleles S 6a and S 6b , proposed to be neutral variants of the same alleles, should be instead considered different specificities. The promoter sequences have also been analyzed, highlighting regions of homology conserved among all the alleles.
Collapse
Affiliation(s)
- Paolo De Franceschi
- Dipartimento di Scienze e Tecnologie Agroalimentari (DISTAL), Università degli Studi di Bologna, Bologna, Italy.
| | - Luca Bianco
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy
| | - Alessandro Cestaro
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy
| | - Luca Dondini
- Dipartimento di Scienze e Tecnologie Agroalimentari (DISTAL), Università degli Studi di Bologna, Bologna, Italy
| | - Riccardo Velasco
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy
- Centro di Ricerca in Viticoltura ed Enologia del Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria (CREA-VE), Conegliano, Treviso, Italy
| |
Collapse
|
4
|
Pratas MI, Aguiar B, Vieira J, Nunes V, Teixeira V, Fonseca NA, Iezzoni A, van Nocker S, Vieira CP. Inferences on specificity recognition at the Malus×domestica gametophytic self-incompatibility system. Sci Rep 2018; 8:1717. [PMID: 29379047 PMCID: PMC5788982 DOI: 10.1038/s41598-018-19820-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 01/09/2018] [Indexed: 01/01/2023] Open
Abstract
In Malus × domestica (Rosaceae) the product of each SFBB gene (the pollen component of the gametophytic self-incompatibility (GSI) system) of a S-haplotype (the combination of pistil and pollen genes that are linked) interacts with a sub-set of non-self S-RNases (the pistil component), but not with the self S-RNase. To understand how the Malus GSI system works, we identified 24 SFBB genes expressed in anthers, and determined their gene sequence in nine M. domestica cultivars. Expression of these SFBBs was not detected in the petal, sepal, filament, receptacle, style, stigma, ovary or young leaf. For all SFBBs (except SFBB15), identical sequences were obtained only in cultivars having the same S-RNase. Linkage with a particular S-RNase was further established using the progeny of three crosses. Such data is needed to understand how other genes not involved in GSI are affected by the S-locus region. To classify SFBBs specificity, the amino acids under positive selection obtained when performing intra-haplotypic analyses were used. Using this information and the previously identified S-RNase positively selected amino acid sites, inferences are made on the S-RNase amino acid properties (hydrophobicity, aromatic, aliphatic, polarity, and size), at these positions, that are critical features for GSI specificity determination.
Collapse
Affiliation(s)
- Maria I Pratas
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen 208, 4200-135, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135, Porto, Portugal
| | - Bruno Aguiar
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen 208, 4200-135, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135, Porto, Portugal
| | - Jorge Vieira
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen 208, 4200-135, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135, Porto, Portugal
| | - Vanessa Nunes
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen 208, 4200-135, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135, Porto, Portugal
| | - Vanessa Teixeira
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen 208, 4200-135, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135, Porto, Portugal
| | - Nuno A Fonseca
- European Bioinformatics Institute (EMBL-EBI,) Welcome Trust Genome Campus, CB10 1SD, Cambridge, United Kingdom
| | - Amy Iezzoni
- Michigan State University, East Lansing, MI, 48824-1325, USA
| | | | - Cristina P Vieira
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Alfredo Allen 208, 4200-135, Porto, Portugal.
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135, Porto, Portugal.
| |
Collapse
|
5
|
Ashkani J, Rees DJG. A simple, high-throughput modeling approach reveals insights into the mechanism of gametophytic self-incompatibility. Sci Rep 2016; 6:34732. [PMID: 27721467 PMCID: PMC5056379 DOI: 10.1038/srep34732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 09/15/2016] [Indexed: 11/29/2022] Open
Abstract
Specificity in the GSI response results from the S-haplotype-specific molecular interaction of S-locus F-box (SLF/SFB) and SRNase proteins in the self-incompatibility locus (S-locus). The answer to the question of how these two components of the S-locus (SRNase and SLF/SFB) interact has been gathered from several models. Since there is not enough evidence as to which one is the definitive model, none of them can be ruled out. Despite the identification of interacting protein elements, the mechanism by which SLF/SFB and SRNase interact to differently trigger the self-incompatibility among families and subfamilies remain uncertain. The high-throughput modeling approach demonstrates structural visions into the possible existence of a Collaborative Non-Self Recognition model in apple. These findings postulate several prospects for future investigation providing useful information to guide the implementation of breeding strategies.
Collapse
Affiliation(s)
- Jahanshah Ashkani
- Biotechnology Department, University of the Western Cape, Robert Sobokwe Road, Bellville, 7535, South Africa
- Agricultural Research Council, Biotechnology Platform, Private Bag X5, Onderstepoort, 0110, South Africa
| | - D. J. G. Rees
- Biotechnology Department, University of the Western Cape, Robert Sobokwe Road, Bellville, 7535, South Africa
- Agricultural Research Council, Biotechnology Platform, Private Bag X5, Onderstepoort, 0110, South Africa
| |
Collapse
|
6
|
Matsumoto D, Tao R. Recognition of a wide-range of S-RNases by S locus F-box like 2, a general-inhibitor candidate in the Prunus-specific S-RNase-based self-incompatibility system. PLANT MOLECULAR BIOLOGY 2016; 91:459-69. [PMID: 27071402 DOI: 10.1007/s11103-016-0479-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 04/04/2016] [Indexed: 05/27/2023]
Abstract
Many species in the Rosaceae, the Solanaceae, and the Plantaginaceae exhibit S-RNase-based gametophytic self-incompatibility (GSI). This system comprises S-ribonucleases (S-RNases) as the pistil S determinant and a single or multiple F-box proteins as the pollen S determinants. In Prunus, pollen specificity is determined by a single S haplotype-specific F-box protein (SFB). The results of several studies suggested that SFB exerts cognate S-RNase cytotoxicity, and a hypothetical general inhibitor (GI) is assumed to detoxify S-RNases in non-specific manner unless it is affected by SFB. Although the identity of the GI is unknown, phylogenetic and evolutionary analyses have indicated that S locus F-box like 1-3 (or S locus F-box with low allelic sequence polymorphism 1-3; SLFL1-3), which are encoded by a region of the Prunus genome linked to the S locus, are good GI candidates. Here, we examined the biochemical characteristics of SLFL1-3 to determine whether they have appropriate GI characteristics. Pull-down assays and quantitative expression analyses indicated that Prunus avium SLFL1-3 mainly formed a canonical SCF complex with PavSSK1 and PavCul1A. Binding assays with PavS(1,3,4,6)-RNases showed that PavSLFL1, PavSLFL2, and PavSLFL3 bound to PavS(3)-RNase, all PavS-RNases tested, and none of the PavS-RNases tested, respectively. Together, these results suggested that SLFL2 has the appropriate characteristics to be the GI in sweet cherry pollen, while SLFL1 may redundantly work with SLFL2 to detoxify all S-RNases. We discuss the possible roles of SLFL1-3 as the GI in the Prunus-specific S-RNase-based GSI mechanism.
Collapse
Affiliation(s)
- Daiki Matsumoto
- Faculty of Agriculture, Yamagata University, Tsuruoka, 997-8555, Japan
| | - Ryutaro Tao
- Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan.
| |
Collapse
|
7
|
Sassa H. Molecular mechanism of the S-RNase-based gametophytic self-incompatibility in fruit trees of Rosaceae. BREEDING SCIENCE 2016; 66:116-21. [PMID: 27069396 PMCID: PMC4780795 DOI: 10.1270/jsbbs.66.116] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 11/11/2015] [Indexed: 05/07/2023]
Abstract
Self-incompatibility (SI) is a major obstacle for stable fruit production in fruit trees of Rosaceae. SI of Rosaceae is controlled by the S locus on which at least two genes, pistil S and pollen S, are located. The product of the pistil S gene is a polymorphic and extracellular ribonuclease, called S-RNase, while that of the pollen S gene is a protein containing the F-box motif, SFB (S haplotype-specific F-box protein)/SFBB (S locus F-box brothers). Recent studies suggested that SI of Rosaceae includes two different systems, i.e., Prunus of tribe Amygdaleae exhibits a self-recognition system in which its SFB recognizes self-S-RNase, while tribe Pyreae (Pyrus and Malus) shows a non-self-recognition system in which many SFBB proteins are involved in SI, each recognizing subset of non-self-S-RNases. Further biochemical and biological characterization of the S locus genes, as well as other genes required for SI not located at the S locus, will help our understanding of the molecular mechanisms, origin, and evolution of SI of Rosaceae, and may provide the basis for breeding of self-compatible fruit tree cultivars.
Collapse
|
8
|
Ashkani J, Rees DJG. A Comprehensive Study of Molecular Evolution at the Self-Incompatibility Locus of Rosaceae. J Mol Evol 2015; 82:128-45. [PMID: 26714486 DOI: 10.1007/s00239-015-9726-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 12/16/2015] [Indexed: 10/22/2022]
Abstract
The family Rosaceae includes a range of important fruit trees, most of which have the S-RNase-based self-incompatibility (SI). Several models have been developed to explain how pollen (SLF) and pistil (S-RNase) components of the S-locus interact. It was discovered in 2010 that additional SLF proteins are involved in pollen specificity, and a Collaborative Non-Self Recognition model has been proposed for SI in Solanaceae; however, the validity of such model remains to be elucidated for other species. The results of this study support the divergent evolution of the S-locus genes from two Rosaceae subfamilies, Prunoideae/Amygdaloideae and Maloideae, The difference identified in the selective pressures between the two lineages provides evidence for positive selection at specific sites in both the S-RNase and the SLF proteins. The evolutionary findings of this study support the role of multiple SLF proteins leading to a Collaborative Non-Self Recognition model for SI in the Maloideae. Furthermore, the identification of the sites responsible for SI specificity determination and the mapping of these sites onto the modelled tertiary structure of ancestor proteins provide useful information for rational functional redesign and protein engineering for the future engineering of new functional alleles providing increased diversity in the SI system in the Maloideae.
Collapse
Affiliation(s)
- Jahanshah Ashkani
- Biotechnology Department, University of the Western Cape, Private Bag X17, Bellville, 7535, South Africa. .,Biotechnology Platform, Agricultural Research Council, Private Bag X5, Onderstepoort, 0110, South Africa.
| | - D J G Rees
- Biotechnology Platform, Agricultural Research Council, Private Bag X5, Onderstepoort, 0110, South Africa
| |
Collapse
|
9
|
Genome-wide characterization and analysis of F-box protein-encoding genes in the Malus domestica genome. Mol Genet Genomics 2015; 290:1435-46. [PMID: 25855485 DOI: 10.1007/s00438-015-1004-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 01/29/2015] [Indexed: 10/24/2022]
Abstract
The F-box protein family is a large family that is characterized by conserved F-box domains of approximately 40-50 amino acids in the N-terminus. F-box proteins participate in diverse cellular processes, such as development of floral organs, signal transduction and response to stress, primarily as a component of the Skp1-cullin-F-box (SCF) complex. In this study, using a global search of the apple genome, 517 F-box protein-encoding genes (F-box genes for short) were identified and further subdivided into 12 groups according to the characterization of known functional domains, which suggests the different potential functions or processes that they were involved in. Among these domains, the galactose oxidase domain was analyzed for the first time in plants, and this domain was present with or without the Kelch domain. The F-box genes were distributed in all 17 apple chromosomes with various densities and tended to form gene clusters. Spatial expression profile analysis revealed that F-box genes have organ-specific expression and are widely expressed in all organs. Proteins that contained the galactose oxidase domain were highly expressed in leaves, flowers and seeds. From a fruit ripening expression profile, 166 F-box genes were identified. The expressions of most of these genes changed little during maturation, but five of them increased significantly. Using qRT-PCR to examine the expression of F-box genes encoding proteins with domains related to stress, the results revealed that F-box proteins were up- or down-regulated, which suggests that F-box genes were involved in abiotic stress. The results of this study helped to elucidate the functions of F-box proteins, especially in Rosaceae plants.
Collapse
|
10
|
Minamikawa MF, Koyano R, Kikuchi S, Koba T, Sassa H. Identification of SFBB-containing canonical and noncanonical SCF complexes in pollen of apple (Malus × domestica). PLoS One 2014; 9:e97642. [PMID: 24847858 PMCID: PMC4029751 DOI: 10.1371/journal.pone.0097642] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 04/22/2014] [Indexed: 12/04/2022] Open
Abstract
Gametophytic self-incompatibility (GSI) of Rosaceae, Solanaceae and Plantaginaceae is controlled by a single polymorphic S locus. The S locus contains at least two genes, S-RNase and F-box protein encoding gene SLF/SFB/SFBB that control pistil and pollen specificity, respectively. Generally, the F-box protein forms an E3 ligase complex, SCF complex with Skp1, Cullin1 (CUL1) and Rbx1, however, in Petunia inflata, SBP1 (S-RNase binding protein1) was reported to play the role of Skp1 and Rbx1, and form an SCFSLF-like complex for ubiquitination of non-self S-RNases. On the other hand, in Petunia hybrida and Petunia inflata of Solanaceae, Prunus avium and Pyrus bretschneideri of Rosaceae, SSK1 (SLF-interacting Skp1-like protein1) is considered to form the SCFSLF/SFB complex. Here, we isolated pollen-expressed apple homologs of SSK1 and CUL1, and named MdSSK1, MdCUL1A and MdCUL1B. MdSSK1 was preferentially expressed in pollen, but weakly in other organs analyzed, while, MdCUL1A and MdCUL1B were almost equally expressed in all the organs analyzed. MdSSK1 transcript abundance was significantly (>100 times) higher than that of MdSBP1. In vitro binding assays showed that MdSSK1 and MdSBP1 interacted with MdSFBB1-S9 and MdCUL1, and MdSFBB1-S9 interacted more strongly with MdSSK1 than with MdSBP1. The results suggest that both MdSSK1-containing SCFSFBB1 and MdSBP1-containing SCFSFBB1-like complexes function in pollen of apple, and the former plays a major role.
Collapse
Affiliation(s)
- Mai F. Minamikawa
- Graduate School of Horticulture, Chiba University, Matsudo, Chiba, Japan
| | - Ruriko Koyano
- Graduate School of Horticulture, Chiba University, Matsudo, Chiba, Japan
| | - Shinji Kikuchi
- Graduate School of Horticulture, Chiba University, Matsudo, Chiba, Japan
| | - Takato Koba
- Graduate School of Horticulture, Chiba University, Matsudo, Chiba, Japan
| | - Hidenori Sassa
- Graduate School of Horticulture, Chiba University, Matsudo, Chiba, Japan
| |
Collapse
|