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
Vs.
White +
Far-red
White
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
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Ernest and Pauline Jaworski
Howard Hughes Medical Institute
Dr. Kevin Ahern
Dr. Todd Mockler
Sam Fox
Erik Rowley
Jessica Murray
Dr. Serge Filichkin