Presenter: Natalya Vienna Triplett

Faculty Sponsor: Samuel P. Hazen

School: UMass Amherst

Research Area: Biology

Session: Poster Session 5, 3:15 PM - 4:00 PM, 163, C16

ABSTRACT

Secondary cell walls in grasses provide structural strength, enable water transport, and represent the largest carbon sinks in terrestrial ecosystems. Despite their importance, the genetic regulation of secondary cell wall formation remains incompletely understood. This study investigates the roles of two genes, HDAC19, a histone deacetylase that regulates gene expression through chromatin modification, and GF14H, a 14-3-3 protein involved in protein–protein interactions and signal transduction, in controlling secondary cell wall thickening in the model grass Brachypodium distachyon. Both genes have been implicated in abiotic stress responses, and mutant lines exhibit shorter stems with increased thickness, suggesting altered cell wall development. To characterize these phenotypes, stem cross-sections were analyzed using histology and phloroglucinol staining to visualize lignin, a major component of secondary cell walls. Cell wall thickness was quantified in multiple stem cell types, including mestome, interfascicular fibers, and xylem. Preliminary results indicate a significant increase in secondary cell wall thickness in interfascicular fibers of the mutant lines compared to wild type. These findings suggest that HDAC19 and GF14H function as regulators of secondary cell wall deposition. This work contributes to understanding the genetic control of cell wall formation in grasses and provides insight into mechanisms that influence plant structure and biomass accumulation.