The resurrection1 (rst1) locus of Arabidopsis controls a unique development of plant growth associated with DNA methylation and susceptibility to various pathogens
Abstract
Plants continuously react to biotic and abiotic factors in the environment by altering their growth and development. Biotic stress can affect plant development and reduce the yield of agricultural crops. Plant response to pathogen attack is highly programmed and involves complex genetic regulatory network. Numerous studies have attempted to understand how plants respond to pathogen attack. In spite of this, many factors that play an important role in plant response to pathogenic fungi attack are still unknown. Our goal in this project is to enlighten our understanding of the connection between plant defense mechanisms and developmental programs associated with DNA methylation. We recently isolated a novel Arabidopsis mutant, resurrection1 (rst1), which shows reduced inflorescence stem glaucousness due to altered cuticular wax structure and composition. Three to four weeks after germination the rosette leaves of rst1 become completely necrotic, followed by the production of a new inflorescence from lateral buds (therefore the name resurrection). Interestingly, our preliminary results indicate that rst1 plants were highly susceptible to Erysiphe cichoracearum an obligate biotrophic pathogen that causes powdery mildew. However, E. cichoracearum does not germinate on the leaves of the wild type ecotype C24. Interestingly, unstable genetic segregation and variation in expression of the rst1 mutants, moreover phenotypic abnormalities of rst1 mutants lead us to suspect that Rst1 plays a role in epigenetic mechanisms. These results suggest that mutation of Rst1 has removed factors that play an important role in preventing Erysiphe cichoracearum hyphal penetration into the leaf or has derived factors that normally deter pathogen growth and invasion at the surface of leaf. From these initial data, we hypothesized that Rst1 is an important factor for pathogen interaction and plant development associated with DNA methylation. We described here the interaction between rst1 alleles and biotrophic and necrotrophic pathogens, and the abnormal growth associated with DNA hypomethylation of rst1 mutants.
Degree
Ph.D.
Advisors
Bressan, Purdue University.
Subject Area
Plant Pathology|Plant sciences
Off-Campus Purdue Users:
To access this dissertation, please log in to our
proxy server.