Tackling climate change by enhancing carbon sequestration through improved photosynthetic efficiency and root architecture
Peggy G. Lemaux, Professor of Cooperative Extension
Plant and Microbial Biology
Applications for Fall 2024 are closed for this project.
General Description and Research Approach.
Every country is facing effects of climate change – not just heatwaves but also more severe and frequent rainstorms, increased threat of wildfires and more intense drought. All these factors have negative effects on crop yields, causing food insecurity worldwide. Greenhouse gases, e.g., CO2, and methane, are culprits in these changes.
One approach to address these issues is to capture more carbon to reduce atmospheric CO2, perhaps slowing or even reversing global warming. Plants, as bio-factories, capture atmospheric carbon through photosynthetic CO2 fixation and store it through carbon sequestration in its roots, stems and leaves. Plant genetic engineering and CRISPR-editing can be used to increase carbon sequestration. The goal of our laboratory is to identify genes to improve CO2 fixation and use genetic engineering or CRISPR-editing to improve carbon sequestration through improved photosynthetic efficiency and altered root architecture. Our efforts focus on Sorghum bicolor, the fifth most widely grown cereal crop worldwide. Sorghum is an attractive multipurpose crop as a source of food, feed, and as a bioenergy feedstock. Compared to C3 photosynthesis used in crops like rice and wheat, sorghum uses the more efficient C4 photosynthetic pathway, resulting in higher CO2 fixation. Sorghum is also highly adaptable to varying heat and water environments, making it a promising crop for the future.
Few studies have delved into the genetic basis of sorghum’s drought tolerance or have studied the relationship between the architecture and senescence of roots under water-stressed conditions. Our lab led the DOE-funded EPICON project (https://doi.org/10.1073/pnas.190750011 ), developing transcriptomic and metabolomic data on sorghum grown under different drought treatments in the field. One sorghum genotype, a ‘Stay Green’ variety, remained green and notably yielded grain, even after 65 days with no water applied after flowering. Understanding the relationships among the Stay Green trait, root architecture, which enables deep soil water uptake, and altered drought responses, which extend the time plants sequester carbon, could provide strategies to engineer and edit plants with higher productivity under a future hotter, drier climate.
For this project, EPICON data is being used to identify genes differentially expressed in the Stay Green sorghum genotype. Candidates differentially expressed in roots will be edited and engineered to determine their impact on root architecture and post-flowering drought tolerance. We will drive expression of candidate root architecture and Stay Green genes, using root-specific promoters. Since expression of most identified genes has not been studied, we will test candidate promoters and those found to drive expression in appropriate areas of the root will be used for engineering and editing specific root architecture genes.
Role: The interests and skill level of the student will determine the specific duties and goals in which they will be involved. The student will learn molecular cloning, genetic engineering and CRISPR editing and molecular analyses of transgenic sorghum, plus other techniques used in plant genetic research. The student will help test candidate root promoters and use that data to build constructs and perform engineering and editing to alter CO2 sequestration. There may also be opportunities to learn about sorghum crossing and marker-assisted breeding. As necessary, the student will care for plants in growth chambers and the greenhouse, and collect experimental materials. The student will work directly with a postdoctoral fellow, a staff research associate, other undergraduates and the principal investigator. Student will participate in lab meetings and contribute to presentations and publications, as appropriate. The time commitment required will be negotiated with the student.
Qualifications: Willingness to learn plant genetics techniques and enthusiasm for research are necessary. Previous molecular biology and data analysis experience outside the classroom is desired but not mandatory. Care-to-detail and commitment to scheduled work times are critical.
Day-to-day supervisor for this project: Tamara Miller, Post-Doc
Hours: to be negotiated
Related website: https://plantandmicrobiology.berkeley.edu/users/peggy-g-lemaux
Biological & Health Sciences