1. AP2/EREBP Transcription Factor Family
Garen and Joanna

2. Transcription Factors
Transcription Factors (TF) are proteins that regulate the transcription of genes
Three general categories of TFs
Bind to RNA Polymerase
Bind to another TF
Bind to specific DNA sequences
Most bind upstream of the target gene in the promoter sequence

3. What is AP2? AP2 derives name from APETALA2 protein Unique to Plants
Domain sequence of 70 amino acids
Unique to Plants
Contain either 1 or 2 AP2 Domains
EREBP and AP2 subfamilies
Present during many stages of plant development in all organs
Our focus is seed development

4. 3 Types of AP2 Proteins Three classes of single AP2 repeat proteins
Ethylene Response Elements Binding Proteins (EREBPs)
Dehydration Response Elements (DREs)
RAV1 and RAV2

5. Sub-families of AP2 Sub-family EREBP RAV DRE Binding Sequence CAACA+
TAAGAGCCGCC
CAACA+
CACCTG
[ag]CCGAC

6. What is its role in plants?
Are involved in various aspects of plant growth and development
Flower Development
Hormone signal transduction
Cellular Differentiation
Responds to biotic and abiotic stresses
Drought (DREs)
Low Temperature
Pathogens

7. More specifically…
Certain AP2 genes control seed mass and seed size in Arabidopsis.
May negatively affect gibberellin activity in regulating cell size and number during seed development
Large seed size correlates with deformed flowers

8. Mechanisms
Wildtype Seed
Seed size affected two different ways when AP2-10 is non-functional
Seed cavity size enlarged
This allows for extended growth of cotyledons
Prolonged mitotic activity after torpedo stage leads results in extended growth of embryo
Wildtype Seed Coat
Mutant Seed
Mutant Seed Coat

9. Conclusion
AP2 transcription factors are crucial to many plant processes
Its effects on seed development may have significant repercussions in other organs, as exemplified by deformed flowers
Masking?
There’s still much we don’t know, but the research continues