1
|
Macgregor SR, Beronilla PKS, Goring DR. The Arabidopsis SNARE complex genes regulate the early stages of pollen-stigma interactions. PLANT REPRODUCTION 2024; 37:309-320. [PMID: 38038738 DOI: 10.1007/s00497-023-00488-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 10/22/2023] [Indexed: 12/02/2023]
Abstract
KEY MESSAGE The VAMP721, VAMP722, SYP121, SYP122 and SNAP33 SNAREs are required in the Arabidopsis stigma for pollen hydration, further supporting a role for vesicle trafficking in the stigma's pollen responses. In the Brassicaceae, the process of accepting compatible pollen is a key step in successful reproduction and highly regulated following interactions between the pollen and the stigma. Central to this is the initiation of secretion in the stigma, which is proposed to provide resources to the pollen for hydration and germination and pollen tube growth. Previously, the eight exocyst subunit genes were shown to be required in the Arabidopsis stigma to support these pollen responses. One of the roles of the exocyst is to tether secretory vesicles at the plasma membrane for membrane fusion by the SNARE complex to enable vesicle cargo release. Here, we investigate the role of Arabidopsis SNARE genes in the stigma for pollen responses. Using a combination of different knockout and knockdown SNARE mutant lines, we show that VAMP721, VAMP722, SYP121, SYP122 and SNAP33 are involved in this process. Significant disruptions in pollen hydration were observed following pollination of wildtype pollen on the mutant SNARE stigmas. Overall, these results place the Arabidopsis SNARE complex as a contributor in the stigma for pollen responses and reaffirm the significance of secretion in the stigma to support the pollen-stigma interactions.
Collapse
Affiliation(s)
- Stuart R Macgregor
- Department of Cell & Systems Biology, University of Toronto, Toronto, M5S 3B2, Canada
- Faculty of Science, York University, Toronto, Canada
| | - Paula K S Beronilla
- Department of Cell & Systems Biology, University of Toronto, Toronto, M5S 3B2, Canada
| | - Daphne R Goring
- Department of Cell & Systems Biology, University of Toronto, Toronto, M5S 3B2, Canada.
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, M5S 3B2, Canada.
| |
Collapse
|
2
|
Beronilla PKS, Goring DR. Investigating a role for PUB17 and PUB16 in the self-incompatibility signaling pathway in transgenic Arabidopsis thaliana. PLANT DIRECT 2024; 8:e622. [PMID: 39044900 PMCID: PMC11263811 DOI: 10.1002/pld3.622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 01/23/2024] [Accepted: 07/03/2024] [Indexed: 07/25/2024]
Abstract
In Brassicaceae self-incompatibility (SI), self-pollen rejection is initiated by the S-haplotype specific interactions between the pollen S cysteine-rich/S-locus protein 11 (SCR/SP11) ligands and the stigma S receptor kinases (SRK). In Brassica SI, a member of the Plant U-Box (PUB) E3 ubiquitin ligases, ARM-repeat containing 1 (ARC1), is then activated by SRK in this stigma and cellular events downstream of this cause SI pollen rejection by inhibiting pollen hydration and pollen tube growth. During the transition to selfing, Arabidopsis thaliana lost the SI components, SCR, SRK, and ARC1. However, this trait can be reintroduced into A. thaliana by adding back functional copies of these genes from closely related SI species. Both SCR and SRK are required for this, though the degree of SI pollen rejection varies between A. thaliana accessions, and ARC1 is not always needed to produce a strong SI response. For the A. thaliana C24 accession, only transforming with Arabidopsis lyrata SCR and SRK confers a strong SI trait (SI-C24), and so here, we investigated if ARC1-related PUBs were involved in the SI pathway in the transgenic A. thaliana SI-C24 line. Two close ARC1 homologs, PUB17 and PUB16, were selected, and (Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) technology was used to generate pub17 and pub16 mutations in the C24 accession. These mutants were then crossed into the transgenic A. thaliana SI-C24 line and their potential impact on SI pollen rejection was investigated. Overall, we did not observe any significant differences in SI responses to implicate PUB17 and PUB16 functioning in the transgenic A. thaliana SI-C24 stigma to reject SI pollen.
Collapse
Affiliation(s)
| | - Daphne R. Goring
- Department of Cell & Systems BiologyUniversity of TorontoTorontoCanada
- Centre for the Analysis of Genome Evolution & FunctionUniversity of TorontoTorontoCanada
| |
Collapse
|
3
|
Lee HK, Canales Sanchez LE, Bordeleau SJ, Goring DR. Arabidopsis leucine-rich repeat malectin receptor-like kinases regulate pollen-stigma interactions. PLANT PHYSIOLOGY 2024; 195:343-355. [PMID: 38270530 DOI: 10.1093/plphys/kiae038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 12/19/2023] [Accepted: 12/21/2023] [Indexed: 01/26/2024]
Abstract
Flowering plants contain tightly controlled pollen-pistil interactions required for promoting intraspecific fertilization and preventing interspecific hybridizations. In Arabidopsis (Arabidopsis thaliana), several receptor kinases (RKs) are known to regulate the later stages of intraspecific pollen tube growth and ovular reception in the pistil, but less is known about RK regulation of the earlier stages. The Arabidopsis RECEPTOR-LIKE KINASE IN FLOWERS1 (RKF1)/RKF1-LIKE (RKFL) 1-3 cluster of 4 leucine-rich repeat malectin (LRR-MAL) RKs was previously found to function in the stigma to promote intraspecific pollen hydration. In this study, we tested additional combinations of up to 7 Arabidopsis LRR-MAL RK knockout mutants, including RKF1, RKFL1-3, LysM RLK1-INTERACTING KINASE1, REMORIN-INTERACTING RECEPTOR1, and NEMATODE-INDUCED LRR-RLK2. These LRR-MAL RKs were discovered to function in the female stigma to support intraspecific Arabidopsis pollen tube growth and to establish a prezygotic interspecific barrier against Capsella rubella pollen. Thus, this study uncovered additional biological functions for this poorly understood group of RKs in regulating the early stages of Arabidopsis sexual reproduction.
Collapse
Affiliation(s)
- Hyun Kyung Lee
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3B2, Canada
| | | | - Stephen J Bordeleau
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3B2, Canada
| | - Daphne R Goring
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3B2, Canada
- Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, ON M5S 3B2, Canada
| |
Collapse
|
4
|
Moussu S, Lee HK, Haas KT, Broyart C, Rathgeb U, De Bellis D, Levasseur T, Schoenaers S, Fernandez GS, Grossniklaus U, Bonnin E, Hosy E, Vissenberg K, Geldner N, Cathala B, Höfte H, Santiago J. Plant cell wall patterning and expansion mediated by protein-peptide-polysaccharide interaction. Science 2023; 382:719-725. [PMID: 37943924 DOI: 10.1126/science.adi4720] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 09/22/2023] [Indexed: 11/12/2023]
Abstract
Assembly of cell wall polysaccharides into specific patterns is required for plant growth. A complex of RAPID ALKALINIZATION FACTOR 4 (RALF4) and its cell wall-anchored LEUCINE-RICH REPEAT EXTENSIN 8 (LRX8)-interacting protein is crucial for cell wall integrity during pollen tube growth, but its molecular connection with the cell wall is unknown. Here, we show that LRX8-RALF4 complexes adopt a heterotetrametric configuration in vivo, displaying a dendritic distribution. The LRX8-RALF4 complex specifically interacts with demethylesterified pectins in a charge-dependent manner through RALF4's polycationic surface. The LRX8-RALF4-pectin interaction exerts a condensing effect, patterning the cell wall's polymers into a reticulated network essential for wall integrity and expansion. Our work uncovers a dual structural and signaling role for RALF4 in pollen tube growth and in the assembly of complex extracellular polymers.
Collapse
Affiliation(s)
- Steven Moussu
- The Plant Signaling Mechanisms Laboratory, Department of Plant Molecular Biology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Hyun Kyung Lee
- The Plant Signaling Mechanisms Laboratory, Department of Plant Molecular Biology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Kalina T Haas
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Caroline Broyart
- The Plant Signaling Mechanisms Laboratory, Department of Plant Molecular Biology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Ursina Rathgeb
- Department of Plant Molecular Biology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Damien De Bellis
- Department of Plant Molecular Biology, University of Lausanne, 1015 Lausanne, Switzerland
- Electron Microscopy Facility, University of Lausanne, 1015 Lausanne, Switzerland
| | | | - Sébastjen Schoenaers
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
- Integrated Molecular Plant Physiology Research (IMPRES), Department of Biology, University of Antwerp, 2020 Antwerp, Belgium
| | - Gorka S Fernandez
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, 8008 Zurich, Switzerland
| | - Ueli Grossniklaus
- Department of Plant and Microbial Biology & Zurich-Basel Plant Science Center, University of Zurich, 8008 Zurich, Switzerland
| | | | - Eric Hosy
- IINS, CNRS UMR5297, University of Bordeaux, 33000 Bordeaux, France
| | - Kris Vissenberg
- Integrated Molecular Plant Physiology Research (IMPRES), Department of Biology, University of Antwerp, 2020 Antwerp, Belgium
- Plant Biochemistry & Biotechnology Lab, Department of Agriculture, Hellenic Mediterranean University, Stavromenos PC 71410, Heraklion, Crete, Greece
| | - Niko Geldner
- Department of Plant Molecular Biology, University of Lausanne, 1015 Lausanne, Switzerland
| | | | - Herman Höfte
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Julia Santiago
- The Plant Signaling Mechanisms Laboratory, Department of Plant Molecular Biology, University of Lausanne, 1015 Lausanne, Switzerland
| |
Collapse
|
5
|
Macgregor SR, Lee HK, Nelles H, Johnson DC, Zhang T, Ma C, Goring DR. Autophagy is required for self-incompatible pollen rejection in two transgenic Arabidopsis thaliana accessions. PLANT PHYSIOLOGY 2022; 188:2073-2084. [PMID: 35078230 PMCID: PMC8969033 DOI: 10.1093/plphys/kiac026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 12/22/2021] [Indexed: 05/16/2023]
Abstract
Successful reproduction in the Brassicaceae is mediated by a complex series of interactions between the pollen and the pistil, and some species have an additional layer of regulation with the self-incompatibility trait. While the initial activation of the self-incompatibility pathway by the pollen S-locus protein 11/S locus cysteine-rich protein and the stigma S Receptor Kinase is well characterized, the downstream mechanisms causing self-pollen rejection are still not fully understood. In previous studies, we detected the presence of autophagic bodies with self-incompatible (SI) pollinations in Arabidopsis lyrata and transgenic Arabidopsis thaliana lines, but whether autophagy was essential for self-pollen rejection was unknown. Here, we investigated the requirement of autophagy in this response by crossing mutations in the essential AUTOPHAGY7 (ATG7) and ATG5 genes into two different transgenic SI A. thaliana lines in the Col-0 and C24 accessions. By using these previously characterized transgenic lines that express A. lyrata and Arabidopsis halleri self-incompatibility genes, we demonstrated that disrupting autophagy weakened their SI responses in the stigma. When the atg7 or atg5 mutations were present, an increased number of SI pollen was found to hydrate and form pollen tubes that successfully fertilized the SI pistils. Additionally, we confirmed the presence of GFP-ATG8a-labeled autophagosomes in the stigmatic papillae following SI pollinations. Together, these findings support the requirement of autophagy in the self-incompatibility response and add to the growing understanding of the intracellular mechanisms employed in the transgenic A. thaliana stigmas to reject self-pollen.
Collapse
Affiliation(s)
- Stuart R Macgregor
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada M5S 3B2
| | | | - Hayley Nelles
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada M5S 3B2
| | - Daniel C Johnson
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada M5S 3B2
| | - Tong Zhang
- National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement in Wuhan, Huazhong Agricultural University, Wuhan 430070, China
| | - Chaozhi Ma
- National Key Laboratory of Crop Genetic Improvement, National Center of Rapeseed Improvement in Wuhan, Huazhong Agricultural University, Wuhan 430070, China
| | | |
Collapse
|
6
|
Lee HK, Goring DR. Two subgroups of receptor-like kinases promote early compatible pollen responses in the Arabidopsis thaliana pistil. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:1198-1211. [PMID: 33097927 DOI: 10.1093/jxb/eraa496] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 10/20/2020] [Indexed: 06/11/2023]
Abstract
In flowering plants, cell-cell communication between the compatible pollen grain/growing pollen tube and the pistil is an essential component for successful sexual reproduction. In Arabidopsis thaliana, the later stages of this dialogue are mediated by several peptide ligands and receptors that guide pollen tubes to the ovules for the release of sperm cells. Despite a detailed understanding of these processes, a key gap remains regarding the nature of the regulators that function at the earlier stages which are essential steps leading to fertilization. Here, we report on new functions for A. thaliana Receptor-Like Kinase (RLK) genes belonging to the LRR-II and LRR-VIII-2 RLK subgroups in the female reproductive tract to regulate compatible pollen hydration and the early stages of pollen tube growth. Mutant pistils for the A. thaliana RKF1 gene cluster were observed to support reduced wild-type pollen hydration and, when combined with the SERK1 and SERK3/BAK1 mutations, reduced pollen tube travel distances occurred. As these mutant pistils displayed a wild-type morphology, we propose that the observed altered compatible pollen responses result from an impaired pollen-pistil dialogue at these early stages.
Collapse
Affiliation(s)
- Hyun Kyung Lee
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada
| | - Daphne R Goring
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Canada
| |
Collapse
|