Analysis of Physiological Characteristics and Gene Expression Associated with Different
Light Conditions in Brachypodium distachyon
By Jared Streich,Research lead by
Sam Fox and Dr. Todd Mockler
Introduction
• Light sensitive proteins called phytochromes and cryptochromes regulate and or trigger certain biochemical and cellular processes.
Phytochromes and Cryptochromes
• What is a phytochrome and cryptochrome?
Brachypodium distachyon
• Grass model organism for monocot plants
• Ideal for research
• Accession Bd21 used
Arabidopsis thaliana vs. Brachypodium distachyon
• Arabidopsis is limited in modeling monocots plants
• Brachypodium is a monocot
Question• What are the affects of light quality on
Brachypodium distachyon growth, development and regulation of gene expression?
Goals
• Identified physiological differences
• Create lists of up and down regulated genes
• Mapped metabolic pathways
• Identified phytochrome and cryptochrome genes
Hypothesis
• Plants grown in certain colors of light will have differences in physiology and gene expression.
Experiment Composition
–Analyze gene expression characteristics
–Analyze growth and development
–Conclude relations of both
Gene Expression
Red
Blue
White + Far-red
White
Vs.
Dark (Control)
Gene Expression
Gene Data Analysis• Microarray technology used to analyze cDNA
Gene Data Analysis
• Create clusters of up and down regulated genes via p-value
Conclusion: Gene Count Analysis
• Shared genes in red and white light
• Shared genes in blue light and white light
• Most down regulated genes in white light
• Most up regulated genes in blue light
Gene Data Analysis
Conclusion: Genes Isolated as Likely Candidates for Phytochrome and Cryptochromes in BD21
• Phytochrome A Bradi1g10520.1
• Phytochrome B Bradi1g64360.1
• Phytochrome C Bradi1g08400.1
• Cryptochrome A Cry1a Bradi3g46590.1
• Cryptochrome B Cry1b Bradi5g11990.1
• Cryptochrome C Cry2 Bradi3g49204.1
Physical Measurements
Tissues length–Root length
–Above ground tissue
Conclusion: Physiological
• Red: Most overall growth
• White: Most root growth
• White + far-red: Longest leaves
• Blue: slowed growth in all tissue types.
Biomass and Physiological Growth
Flowering Time• All conditions flowered within all standard
deviations
Summary
• Possibly identified phytochrome and cryptochrome genes
• Biomass varies by light condition
• Physiological growth varies by light condition
• Flowering time is not effected by light conditions
Future Directions:
• Continue with gene expression analysis
• Isolate and over express genes of interest
• Transgenic plants of other genus with isolated genes
• Affects of adding far-red on white light condition
• Research flowering time regulation
Acknowledgements
• Ernest and Pauline Jaworski• Howard Hughes Medical Institute• Dr. Kevin Ahern• Dr. Todd Mockler• Sam Fox• Erik Rowley• Jessica Murray• Dr. Serge Filichkin