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