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

本项目将在分子水平上研究海藻如何感知和应对压力。该合作团队将以海藻taxxiformis天冬酰胺为模型系统，研究海藻中基因转录和酶的生化活性如何通过合成破坏臭氧的污染物溴仿来应对胁迫。海藻基因操作的工具尚未开发出来，这项研究将为这一全球重要海洋生物群体的基因调控途径提供见解。全球变暖导致的海洋温度升高可能会增加海藻中溴仿的产量，更好地了解其产生的分子机制可能会对环境和生物经济产生影响。在这项工作的过程中，一批研究生、博士后科学家和研究科学家将接受基因组学、酶生物化学、计算和有机生物学的跨学科培训。此外，将为太平洋岛民本科生提供化学和生物科学的动手实验教学，他们是STEM教育中最缺乏服务的社区之一。本研究项目对提供活性氧（如海藻中的过氧化氢）的酶、提供硫模板化聚酮碳氢化合物底物的酶以及使用过氧化氢和聚酮碳氢化合物底物合成溴仿的卤化酶进行生化表征。利用靶向基因转录谱和非靶向转录组测序相结合的方法，将在模型海洋巨藻taxxiformis中查询编码这些产溴仿酶的基因对生物和非生物胁迫的分子水平响应。将进一步努力在其他海藻（如巨囊藻）的酶中发现溴仿生物合成基因。综上所述，这项研究将为臭氧消耗污染物溴仿的自然产生以及海藻在应激下如何调节溴仿的产生提供新的分子见解。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.