Understanding leaf development under high salinity in the extremophyte model, Schrenkiella parvula and leaf shape variation in multiple brassicaceae using multi-omics approach

Author

Prava Adhikari Pantha, Louisiana State University and Agricultural and Mechanical CollegeFollow

Degree

Doctor of Philosophy (PhD)

Department

Biological Sciences

Document Type

Dissertation

Abstract

Schrenkiella parvula, a wild relative of Arabidopsis thaliana from Brassicaceae family, is an extremophyte plant whose natural habitat is the shore of saline lakes in the Irano-Turanian region. It is known for its resilience to thrive in diverse ion-rich environments including Na⁺ and K⁺. In my research, I explored the molecular genetics underlying high Na⁺ tolerance in plants studying S. parvula at different developmental stages and compared the leaf shape variation with closely related two other species, Arabidopsis thaliana and Sisymbrium irio integrating physiological, ionomic, transcriptomic, and metabolomic methodologies.

In my first project, I used integrated omics approach to explore the cellular and molecular processes impacted under longer salt treatment duration at two developmental stages of leaves in S. parvula. My result indicated that the mature leaves preferentially accumulated excess Na compared to young leaves and serves as a sink to protect young and growing leaves. I observed reprogramming of salt transporters specifically in young leaf samples to protect them from accumulating excess salt.

In my second project, I utilized multi-omics approach to understand how S. parvula leaf develops upon high salinity condition starting at early seedling establishment phase to unset of reproductive stage using single leaf (5^th leaves) developed after salt treatment. I identified that S. parvula increased leaf mass per unit area upon salt treatment in 5^th developmental stages with both medium (150 mM NaCl) and high (250 mM NaCl) salt treatment while accumulating significantly higher amounts of Na under both medium and high salt treatment. I observed increased abundance of sugar, amino acids, and fatty acids in the 5^th developmental stage compared to 4^th developmental stage upon salt treatment suggesting those might be playing a role to mitigate osmotic and oxidative stress amidst salt accumulation. Transcriptionally, I observed induced expression of genes related to salt extrusion and vacuolar compartmentalization while suppressed expression of key potassium transport related genes.

In my third project, I explored leaf shape variation within closely related Brassicaceae species. I identified gene expression modules specific to each species suggesting role of those genes in leaf shape variation and adaptation to the extreme environment.

Date

1-13-2025

Recommended Citation

Adhikari Pantha, Prava, "Understanding leaf development under high salinity in the extremophyte model, Schrenkiella parvula and leaf shape variation in multiple brassicaceae using multi-omics approach" (2025). LSU Doctoral Dissertations. 6673.
https://repository.lsu.edu/gradschool_dissertations/6673

Committee Chair

Larkin, John C.