Research

Some of the current research topics in the lab include:

Functional genomics in the green lineage using Chlamydomonas:

Many genes in plants and algae have unknown functions. Using high-throughput methods we screened a Chlamydomonas mutant library of 200k mutants for growth phenotypes in over 100 conditions, including abiotic stresses (heat, cold, light, CO2, salt, UV, toxins) and biotic stresses (algal predators). These screens are revealing new genes important in coping with environmental stress in algae and also higher plants. Some plant homologs of genes identified in our screens also show phenotypes in Arabidopsis, demonstrating the power of using an algal system to make discoveries in the green lineage.

Engineering fruit and vegetables for growth in built environments, like on the International Space Station:

In built environments like a spaceship or in a vertical farm, physical space is limited. To grow fruits and vegetables in these environments plants need to be reduced in size and have limited non-edible biomass. Together with Martha Orozco-Cárdenas at the UCR Plant Transformation Research Center and with support from NASA’s TRISH, we are engineering plants specifically designed for growth in these environments. The first crop we are focusing on is tomatoes. We are currently evaluating mutant plants with a phenotype we are calling Small Plants for Agriculture in Confined Environments, or SPACE tomatoes.

Metabolic engineering algae to increase production of bioproducts and biofuels.

We want organisms to produce the products we need, such as fuels and chemicals. These organisms want to produce more of themselves. How can we engineer them to become catalysts to produce the products that we desire? Previous work has shown that altering carbon flux away from starch can increase lipids (TAG) in algae. This increase, however, comes at the cost of overall productivity (Work 2010). We are working on new approaches and new metabolic targets to overcome some of the problems that are often found when an alga’s native metabolism is altered.

Discovering the molecular mechanisms that govern coral-algal symbiosis and how these influence coral bleaching:

Coral form a symbiosis with algae in the genus Symbiodinium. When exposed to stresses, like high temperature, this symbiosis breaks down and the algae leave the coral. This results in coral bleaching and can be devastating to coral reefs. Very little is known about the molecular mechanisms of this symbiosis and how they are perturbed during stress. To discover these underlying mechanisms we are conducting systems level evaluations and mutant screens. We are developing a new model system that will allow for the first time forward genetic screens to identify genes necessary for symbiosis. This system may also allow us to engineer algae that are more tolerant to heat stress and resist bleaching.

Additional topics we like to think about and explore in the lab include:

  • The evolution of algal endosymbiotic relationships, such as the chloroplast.
  • What will agriculture look like in 100 years? 1000 years? How can we engineer plants to produce the food we need in systems that are completely orthogonal to our current agricultural practices, such as on a spaceship or in another built environment?
  • If plants can be reduced to single cells (plant cell cultures) can we treat them like other microbes (such as algae) and subject them to high-throughput methods?