Rotation 1: Validation of a putative MYB transcription factor involved in chloroplast development
Lead Research Organisation:
University of Cambridge
Department Name: School of Biological Sciences
Abstract
BBSRC strategic theme: Bioscience for sustainable agriculture and food
Chloroplasts are essential to photosynthesis and develop during photomorphogenesis. Despite their importance, the mechanisms governing chloroplast development are not fully understood. Two classes of transcription factors (TFs), GOLDEN-LIKE2 (GLK1 and GLK2) and GATA (GNC and CGA1), regulate photomorphogenesis [1,2]. However, glk1 glk2 gnc cga1 quadruple mutants of Arabidopsis thaliana develop a small number of chloroplasts, indicating that additional TFs may control chloroplast development [2].
MYBs are another potential class of transcription factors regulating photomorphogenesis, but a more specific role has yet to be identified [3]. Through an RNA-seq screen for TFs differentially expressed during photomorphogenesis, a candidate MYB has been identified in Marchantia polymorpha. This MYB is conserved across angiosperms, making M. polymorpha a useful model organism due to its streamlined genome.
In this project, we plan to identify how this MYB regulates chloroplast development in M. polymorpha. We will analyse growth and development in mutants of MYB, GLK, and GATA TFs. Mutants are available in the Hibberd lab of the former two TF classes, and we can use CRISPR/Cas9-mediated gene editing to knock-out GNC and CGA1 genes. Through combining mutations in multiple TF classes, we can determine regulatory interactions. We can also combine MYB mutation with brassinosteroid, cytokinin, or HY5 signalling pathway mutations to elucidate downstream signalling. Additionally, ChIP-seq can be used to determine MYB target genes. Furthermore, rescuing mutants of other plant homologues with the Marchantia gene can determine the extent of functional conservation. This approach will provide insight into how this putative MYB TF controls chloroplast biogenesis, contributing to our understanding of this fundamental process.
References
[1] Waters, Mark T., Peng Wang, Muris Korkaric, Richard G. Capper, Nigel J. Saunders, and Jane A. Langdale. (2009). GLK Transcription Factors Coordinate Expression of the Photosynthetic Apparatus in Arabidopsis. The Plant Cell 21 (4): 1109-28.
[2] Cackett, Lee, Leonie H. Luginbuehl, Tina B. Schreier, Enrique Lopez-Juez, and Julian M. Hibberd. (2022). Chloroplast Development in Green Plant Tissues: The Interplay between Light, Hormone, and Transcriptional Regulation. The New Phytologist 233 (5): 2000-2016.
[3] Du, Hai, Yong-Bin Wang, Yi Xie, Zhe Liang, San-Jie Jiang, Shuang-Shuang Zhang, Yu-Bi Huang, and Yi-Xiong Tang. (2013). Genome-Wide Identification and Evolutionary and Expression Analyses of MYB-Related Genes in Land Plants. DNA Research: An International Journal for Rapid Publication of Reports on Genes and Genomes 20 (5): 437-48.
Chloroplasts are essential to photosynthesis and develop during photomorphogenesis. Despite their importance, the mechanisms governing chloroplast development are not fully understood. Two classes of transcription factors (TFs), GOLDEN-LIKE2 (GLK1 and GLK2) and GATA (GNC and CGA1), regulate photomorphogenesis [1,2]. However, glk1 glk2 gnc cga1 quadruple mutants of Arabidopsis thaliana develop a small number of chloroplasts, indicating that additional TFs may control chloroplast development [2].
MYBs are another potential class of transcription factors regulating photomorphogenesis, but a more specific role has yet to be identified [3]. Through an RNA-seq screen for TFs differentially expressed during photomorphogenesis, a candidate MYB has been identified in Marchantia polymorpha. This MYB is conserved across angiosperms, making M. polymorpha a useful model organism due to its streamlined genome.
In this project, we plan to identify how this MYB regulates chloroplast development in M. polymorpha. We will analyse growth and development in mutants of MYB, GLK, and GATA TFs. Mutants are available in the Hibberd lab of the former two TF classes, and we can use CRISPR/Cas9-mediated gene editing to knock-out GNC and CGA1 genes. Through combining mutations in multiple TF classes, we can determine regulatory interactions. We can also combine MYB mutation with brassinosteroid, cytokinin, or HY5 signalling pathway mutations to elucidate downstream signalling. Additionally, ChIP-seq can be used to determine MYB target genes. Furthermore, rescuing mutants of other plant homologues with the Marchantia gene can determine the extent of functional conservation. This approach will provide insight into how this putative MYB TF controls chloroplast biogenesis, contributing to our understanding of this fundamental process.
References
[1] Waters, Mark T., Peng Wang, Muris Korkaric, Richard G. Capper, Nigel J. Saunders, and Jane A. Langdale. (2009). GLK Transcription Factors Coordinate Expression of the Photosynthetic Apparatus in Arabidopsis. The Plant Cell 21 (4): 1109-28.
[2] Cackett, Lee, Leonie H. Luginbuehl, Tina B. Schreier, Enrique Lopez-Juez, and Julian M. Hibberd. (2022). Chloroplast Development in Green Plant Tissues: The Interplay between Light, Hormone, and Transcriptional Regulation. The New Phytologist 233 (5): 2000-2016.
[3] Du, Hai, Yong-Bin Wang, Yi Xie, Zhe Liang, San-Jie Jiang, Shuang-Shuang Zhang, Yu-Bi Huang, and Yi-Xiong Tang. (2013). Genome-Wide Identification and Evolutionary and Expression Analyses of MYB-Related Genes in Land Plants. DNA Research: An International Journal for Rapid Publication of Reports on Genes and Genomes 20 (5): 437-48.
Organisations
People |
ORCID iD |
| Julian Hibberd (Primary Supervisor) | |
| Julia Stewart-Wood (Student) |
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| BB/X010899/1 | 01/10/2023 | 30/09/2028 | |||
| 2887717 | Studentship | BB/X010899/1 | 01/10/2023 | 30/09/2027 | Julia Stewart-Wood |