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Selva C, Yang X, Shirley NJ, Whitford R, Baumann U, Tucker MR. HvSL1 and HvMADS16 promote stamen identity to restrict multiple ovary formation in barley. J Exp Bot 2023; 74:5039-5056. [PMID: 37279531 PMCID: PMC10498024 DOI: 10.1093/jxb/erad218] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 06/01/2023] [Indexed: 06/08/2023]
Abstract
Correct floral development is the result of a sophisticated balance of molecular cues. Floral mutants provide insight into the main genetic determinants that integrate these cues, as well as providing opportunities to assess functional variation across species. In this study, we characterize the barley (Hordeum vulgare) multiovary mutants mov2.g and mov1, and propose causative gene sequences: a C2H2 zinc-finger gene HvSL1 and a B-class gene HvMADS16, respectively. In the absence of HvSL1, florets lack stamens but exhibit functional supernumerary carpels, resulting in multiple grains per floret. Deletion of HvMADS16 in mov1 causes homeotic conversion of lodicules and stamens into bract-like organs and carpels that contain non-functional ovules. Based on developmental, genetic, and molecular data, we propose a model by which stamen specification in barley is defined by HvSL1 acting upstream of HvMADS16. The present work identifies strong conservation of stamen formation pathways with other cereals, but also reveals intriguing species-specific differences. The findings lay the foundation for a better understanding of floral architecture in Triticeae, a key target for crop improvement.
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Affiliation(s)
- Caterina Selva
- Waite Research Institute, School of Agriculture Food and Wine, University of Adelaide, Waite Campus, Urrbrae 5064, South Australia, Australia
| | - Xiujuan Yang
- Waite Research Institute, School of Agriculture Food and Wine, University of Adelaide, Waite Campus, Urrbrae 5064, South Australia, Australia
| | - Neil J Shirley
- Waite Research Institute, School of Agriculture Food and Wine, University of Adelaide, Waite Campus, Urrbrae 5064, South Australia, Australia
| | - Ryan Whitford
- Waite Research Institute, School of Agriculture Food and Wine, University of Adelaide, Waite Campus, Urrbrae 5064, South Australia, Australia
| | - Ute Baumann
- Waite Research Institute, School of Agriculture Food and Wine, University of Adelaide, Waite Campus, Urrbrae 5064, South Australia, Australia
| | - Matthew R Tucker
- Waite Research Institute, School of Agriculture Food and Wine, University of Adelaide, Waite Campus, Urrbrae 5064, South Australia, Australia
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Selva C, Shirley NJ, Houston K, Whitford R, Baumann U, Li G, Tucker MR. HvLEAFY controls the early stages of floral organ specification and inhibits the formation of multiple ovaries in barley. Plant J 2021; 108:509-527. [PMID: 34382710 DOI: 10.1111/tpj.15457] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 08/04/2021] [Accepted: 08/06/2021] [Indexed: 06/13/2023]
Abstract
Transition to the reproductive phase, inflorescence formation and flower development are crucial elements that ensure maximum reproductive success in a plant's life cycle. To understand the regulatory mechanisms underlying correct flower development in barley (Hordeum vulgare), we characterized the multiovary 5 (mov5.o) mutant. This mutant develops abnormal flowers that exhibit mosaic floral organs typified by multiple carpels at the total or partial expense of stamens. Genetic mapping positioned mov5 on the long arm of chromosome 2H, incorporating a region that encodes HvLFY, the barley orthologue of LEAFY from Arabidopsis. Sequencing revealed that, in mov5.o plants, HvLFY contains a single amino acid substitution in a highly conserved proline residue. CRISPR-mediated knockout of HvLFY replicated the mov5.o phenotype, suggesting that HvLFYmov5 represents a loss of function allele. In heterologous assays, the HvLFYmov5 polymorphism influenced protein-protein interactions and affinity for a putative binding site in the promoter of HvMADS58, a C-class MADS-box gene. Moreover, molecular analysis indicated that HvLFY interacts with HvUFO and regulates the expression of floral homeotic genes including HvMADS2, HvMADS4 and HvMADS16. Other distinct changes in expression differ from those reported in the rice LFY mutants apo2/rfl, suggesting that LFY function in the grasses is modulated in a species-specific manner. This pathway provides a key entry point for the study of LFY function and multiple ovary formation in barley, as well as cereal species in general.
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Affiliation(s)
- Caterina Selva
- School of Agriculture Food and Wine, Waite Research Institute, University of Adelaide, Waite Campus, Urrbrae, SA, 5064, Australia
| | - Neil J Shirley
- School of Agriculture Food and Wine, Waite Research Institute, University of Adelaide, Waite Campus, Urrbrae, SA, 5064, Australia
| | - Kelly Houston
- James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Ryan Whitford
- School of Agriculture Food and Wine, Waite Research Institute, University of Adelaide, Waite Campus, Urrbrae, SA, 5064, Australia
| | - Ute Baumann
- School of Agriculture Food and Wine, Waite Research Institute, University of Adelaide, Waite Campus, Urrbrae, SA, 5064, Australia
| | - Gang Li
- School of Agriculture Food and Wine, Waite Research Institute, University of Adelaide, Waite Campus, Urrbrae, SA, 5064, Australia
- School of Life Sciences and Engineering, Southwest University of Science and Technology, Mianyang, Sichuan, 621010, China
| | - Matthew R Tucker
- School of Agriculture Food and Wine, Waite Research Institute, University of Adelaide, Waite Campus, Urrbrae, SA, 5064, Australia
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