KANKSHITA SWAMINATHAN
nutrient cycling. The lab achieves this, in part, by creating new tools and cutting-edge techniques to study Miscanthus and implement meaningful genetic change. In a 2022 preprint, the group de- scribes the successful genomic editing of three types of Miscanthus 2 . Using CRISPR/ Cas9, the team mutated a specific en-
In late 2018, Swaminathan, HudsonAlpha faculty inves- tigator Jeremy Schmutz, and collaborators at the University of Nebraska-Lincoln (UNL) were awarded a grant from the National Science Foundation (NSF) to study nitrogen effi- ciency in the grain and biomass crop sorghum. During the first three years of the project, the team uncovered baseline nitrogen-responsive gene-regulatory networks by growing sorghum under different nitrogen availability conditions in a greenhouse equipped with an automated phenotyping system. HudsonAlpha researchers coupled the phenotypic information from the greenhouse trials at UNL with genomic information from tissue samples to identify key gene net- works involved in sorghum nitrogen use. The original grant included a robust student training program to give students access to valuable, hands-on agricultural research. However, COVID-19 put a pause on many student-oriented learning opportunities. In 2022, the team was awarded a two-year supplement to the grant to continue their research efforts while also increasing the reach of the educational portion. Researchers hope to attain both of these goals by bringing on a third partner, Alabama A&M University (AAMU), a public, historically Black, land-grant university. The supplemental grant aims to address the practical limitations of the first grant by scaling up the number of sorghum genotypes in the study and growing the sorghum in the field. The team will plant 406 sorghum genotypes in fields in Nebraska and Alabama under both sufficient and deficient nitrogen conditions. Manual and automated phenotyping and scoring of plant growth will be collected throughout the growing season. HudsonAlpha researchers will again integrate phenotypic and genome data to pinpoint genes involved in sorghum nitrogen response. Like the original grant, the supplement also includes an educational component. This time, however, the team hopes to engage more minorities who are underrepresent-
dogenous gene called lemon white1 (lw1) in Miscanthus to knock out its function. Lemon white1 is involved in chlorophyll and carotenoid biosynthesis, so the knockout is strikingly apparent by its pale green, striped, or white leaves. This is the first report of successful genome editing in Miscanthus and was confirmed in three species – M. sacchariflorus, M. sinensis and M. × giganteus . The study also validated lw1 knockout as a good visual marker to indicate editing has taken place. Miscanthus is not the only bioenergy grass that Swaminathan’s lab studies. They also focus some of their efforts on switchgrass, another promising source of bioenergy feedstock. Genetic and gene function analysis in switchgrass is challenging due to its self-incompatibility, long life cycle, and variations in ploidy. Swaminathan and her lab recently turned to another closely related plant to test gene function. They successfully transformed Panicum hallii , a perennial, diploid relative of switchgrass 3 . Having a model plant to study baseline gene function and expression will speed up the time to validate important genes in switchgrass. The ability to target specific genes in endogenous gene editing opens a new door for genetic improvement of both Miscanthus and switchgrass for bioenergy feedstock and material for renewable bioproducts. NITROGEN-EFFICIENT BIOENERGY CROPS In addition to improving bioenergy crops, Dr. Swaminathan and her lab are also focused on creating crops that require fewer environmentally taxing inputs, like fertilizers and pesticides. Nitrogen is an important nutrient for plants; however, they cannot utilize atmospheric nitrogen and instead pull bioavailable forms of nitrogen from the soil. Supplementing soil with synthetic nitrogen fertilizers increases the productivity of many agricultural crops. However, nitrogen fertilizers produce negative environmen- tal impacts and are costly to farmers. Plants with better nitrogen use efficiency could offset the need for excessive fertilizer use, thereby mitigating the adverse effects.
ed in STEM fields, es- pecially in agricultur- al sciences. They will mentor and cross- train young research- ers at AAMU. The team hopes to help significantly increase the retention of young scientists in agri- science and broaden
the participation of minorities in agriscience. ■
Dr. Kankshita Swaminathan
RESEARCH REPORT
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