The knowns against the unknowns: Photosynthesis gene discovery through multi-omic survey of photosynthetic mutants during light stress
EMSL Project ID
60382
Abstract
To advance genome-based understanding of photosynthesis, we have generated a high-quality, phenotyped photosynthesis mutant library in the model unicellular green alga, Chlamydomonas reinhardtii. This library is supported by whole-genome sequences of the mutants and a battery of photosynthesis-related quantitative phenotypes for linking genes to phenotypes. From this library we recently published a curated a list of genes whose disruption is predicted to be causative to the photosynthetic defect of the corresponding mutant. A quarter of these genes are already known for their function in photosynthesis, validating our mutant screening strategy. The rest of the genes have limited or unknown annotations offering a direct link to their function.
Our goal is to gain insight into the functions of these unknown-function genes through mining multi-omic patterns across the mutants during perturbation with photosynthetic stress. Mutants in known photosynthesis genes will be included in the generation of these datasets to serve as references. We anticipate discovering groups of mutants that resemble each other, some groups of which include mutants in known-function genes and thus offering a direct lead into the biochemical process and the mechanism in which the genes are involved. Preliminary data shows several mutants in our library are affected in the abundance of photosynthetic complexes, the assembly and disassembly of which are highly regulated in response to environmental stresses. We will further investigate the quantitative dynamics of the proteins involved to gain a mechanistic understanding of the regulatory process of photosynthesis complex assembly and stoichiometry in response to environmental perturbation. It is anticipated that other mutants will exhibit shared proteome phenotype in certain biochemical or cellular pathways (for example, the Calvin-Benson cycle) and will be more closely investigated for quantitative proteomic changes that may reveal regulatory mechanisms under photosynthetic stress.
This research tackles a high-risk challenge of identifying novel gene functions related to photosynthesis using a large-scale mutant library. We will cast a broad net by obtaining a snapshot of the perturbation at the proteome and metabolome levels after a single stress treatment in ~100 mutants, to increase the chances of having multiple mutants sharing patterns. We have generated fine-scale phenotype data identifying the optimal photosynthetic stress condition for each mutant that represents a stressed state without overwhelming the cell with oxidative stress, to enable identification regulatory processes. This work will not only enable gene function discovery for the specific mutants in our library, but it will also establish proteomic database across different photosynthetic mutants that will serve as a resource for gene function discovery in the research community that extends to other biofuel algae and bioenergy crop plants.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2022-10-01
End Date
N/A
Status
Active
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members