1. My Summer 2008 BBSI Experience
By Natasha Williams
Mentor: Wan-Ling Chiu
For my experience this summer, I have been working alongside fellow lab mates on an ongoing project whose purpose is to:

2. Better Understanding of Plant-Cyanobacterial Symbiosis
The Overall Goal of my Research is to Achieve:
Better Understanding of Plant-Cyanobacterial Symbiosis

3. Gunnera and Nostoc’s Symbiosis
Gunnera manicata
Nostoc punctiforme

4. Negative effects of N2 fertilizers

5. Elucidating Host Genes Critical to Plant-Cyanobacterial Symbiosis
Investigating the Role of Flavonoids in G. manicata and N. punctiforme symbiosis

6. What are roles of flavonoids in the development of plant-cyanobacteria symbiosis ???

7. 10 mM nitrate
0.1 mM nitrate

9. N. Punctiforme traveling towards Gunnera seedling.

10. Flavonoids
Polyphenolic compounds with 15 Carbon atoms, 2 benzene rings connected by a 3 carbon chain.

11. 10 mM nitrate 0.1 mM nitrate N - starvation Myb transcription factor
Flavonoid
synthesis
gland
primodia
inhibit
auxin efflux
Localized auxin accumulation
Activation of cell division and gland development
Remobilization of nutrients
from leaves to the stem
High flavonoids at the
10 mM nitrate
0.1 mM nitrate

12. Solving the Mystery Plan:
- Expose flavonoid-deficit Gunnera mutant to cyanobacteria under N2-deprived conditions.
Gunnera Plant
Mutant Gunnera Plant
Functional analysis. How does my summer experience contribute to this project?
Expose to N2-deficient environment in presence of cyanobacteria

14. RNAi
refers to the introduction of homologous double stranded RNA (dsRNA) to specifically target a gene's product, resulting in null or hypomorphic phenotypes. Today RNA interference (RNAi), is a technique in which exogenous, double-stranded RNAs (dsRNAs) that are complimentary to known mRNA's, are introduced into a cell to specifically destroy that particular mRNA, thereby diminishing or abolishing gene expression. Thus, RNA interference (RNAi), is a gene-silencing technique used in studying the absence of normal gene action (by disrupting its activity in vivo, i.e., turning it off) in fruit flies, nematodes, and mammalian cells.

15. Solving the Mystery Methods:
Discovered Gunnera genes responsible for flavonoid production. 
Correctly insert genes w/n specialized RNAi constructs.
Infect plant with construct via agrobacterium-mediated transfer.
Grow up plant and subject to conditions conducive for symbiosis to occur.
Last Summer
Almost finish this step
Functional analysis. How does my summer experience contribute to this project?

16. Acknowledgments God VCU’s Bioinformatics & Bioengineering Institute
National Science Foundation
Jeff Elhai, BBSI Director
Wan-Ling Chiu, my mentor
The Chiu Lab

17. Questions?