Collaborative Research: Bromoform production and ROS response to stress in seaweeds

This project will study how seaweeds sense and respond to stress at the molecular level. The collaborative team will use the seaweed Asparagopsis taxiformis as a model system to study how the transcription of genes and biochemical activities of enzymes in seaweeds respond to stress by the synthesis of the ozone-damaging pollutant bromoform. Tools for the genetic manipulation of seaweed have not yet been developed and this research will provide insight into pathways of gene regulation in this globally important group of marine organisms.

Increasing ocean temperatures due to global warming may increase bromoform production in seaweeds and a better understanding of the molecular mechanisms of its production could have environmental and bioeconomy impacts. During the course of this work, a cohort of graduate students, postdoctoral scientists, and research scientists will receive interdisciplinary training in genomics, enzymological biochemistry, and computational and organismal biology.

In addition, hands-on experimental instruction in chemical and biological sciences will be provided to Pacific Islander undergraduate students, who are one of the most underserved communities in STEM education.

This research project undertakes a biochemical characterization of enzymes involved in furnishing reactive oxygen species such as hydrogen peroxide in seaweeds, enzymes that furnish thiotemplated polyketone hydrocarbon substrates, and halogenating enzymes that use hydrogen peroxide and polyketone hydrocarbon substrates to synthesize bromoform. Using a combination of targeted gene transcriptional profiling and untargeted transcriptome sequencing, a molecular-level response to biotic and abiotic stress of genes encoding these bromoform producing enzymes will be queried in the model marine macroalgae Asparagopsis taxiformis.

Efforts will be extended to discover bromoform biosynthetic genes in enzymes in other seaweeds such the giant kelp Macrocystis. Taken together, this study will provide new molecular insights into the natural production of the ozone-depleting pollutant bromoform and how the production of bromoform is modulated by seaweeds in response to stress.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.