Identification of regulatory molecules involved in pollen development and ovary growth in Solanum lycopersicum
[EN] In angiosperms, fruits serve the purpose of protecting developing seeds and facilitating their dispersal. After flower development, pollination and fertilization trigger the growth of the ovary into a fruit. However, fruit set and enlargement can occur independently of these two processes, resu...
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| Tipo de recurso: | tesis doctoral |
| Fecha de publicación: | 2026 |
| País: | España |
| Institución: | Universitat Politècnica de València (UPV) |
| Repositorio: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Idioma: | inglés |
| OAI Identifier: | oai:dnet:riunet______::4234f610cae56602266239de79804b12 |
| Acceso en línea: | https://riunet.upv.es/handle/10251/233735 |
| Access Level: | acceso abierto |
| Palabra clave: | Desarrollo Fisiología vegetal Tomate Solanum lycopersicum Plant development Anther Pollen Microgametogenesis Heat stress Tomato Parthenocarpy 02.- Poner fin al hambre, conseguir la seguridad alimentaria y una mejor nutrición, y promover la agricultura sostenible |
| Sumario: | [EN] In angiosperms, fruits serve the purpose of protecting developing seeds and facilitating their dispersal. After flower development, pollination and fertilization trigger the growth of the ovary into a fruit. However, fruit set and enlargement can occur independently of these two processes, resulting in seedless (parthenocarpic) fruits. In the domesticated tomato (Solanum lycopersicum), male sterility can induce parthenocarpic fruit development, providing a link between the formation of the male gametophyte and ovary growth. Pollen and anther development are highly coordinated processes that are largely conserved across angiosperms. However, in tomato, the specific network of genes involved in anther development is not fully characterized. The generation and study of parthenocarpic mutants has proven a powerful tool for understanding the mechanisms that connect male gametogenesis and ovary growth in this species, as well as for investigating the origin of parthenocarpy. Furthermore, the male gametophyte is especially sensitive to adverse environmental conditions, and increasing knowledge on pollen development could provide insight into strategies to maintain fertility under rising temperatures. In this work, we have identified SlTPD1 as an essential gene for tapetum formation in the anther and SlTDF1 as a regulator of tapetal function. Transcriptomic and biochemical analysis conducted in Sltpd1 mutants lacking tapetum highlighted the importance of tapetal tissue in maintaining redox homeostasis during male gametogenesis. Both Sltpd1 and Sltdf1 mutants were male-sterile and, subsequently, developed parthenocarpic fruits. However, male-sterile SpTDF1 mutants obtained in the wild relative Solanum pimpinellifolium background did not exhibit parthenocarpy. Bioinformatic analyses identified deletions in the promoters of genes involved in gibberellin biosynthesis, which affect the binding of repressor proteins. These results point to recent changes in regulatory sequences, indicating that parthenocarpy in tomato is a trait that likely originated during domestication. Additionally, a biotechnology approach was developed to enhance pollen thermotolerance. Transcriptomic analyses identified the ascorbate peroxidase SlAPX5 gene as part of a regulatory network controlling redox homeostasis in the anther. A heat-inducible expression of SlAPX5 was introduced in Arabidopsis and tomato by genetic transformation. In vivo and in vitro experiments confirm that ROS detoxification mediated by peroxidase activity conferred heat tolerance to vegetative and reproductive tissues, preserving fertility and securing plant yield. |
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