Importance of microRNA for seedling development in Arabidopsis thaliana

1
Importance of microRNA for seedling development
in Arabidopsis thaliana

• Jennifer Coppersmith
• Department of Biochemistry and Biophysics
• Mentor Dr. Hiro Nonogaki (Horticulture)

2
Significance of Seed Development

• Agriculture and Food
• Why Arabidopsis?

pgrc3.agr.ca/images/seeds.gif
3
Arabidopsis Seed Structure
4
Overview of Experiment
SPL13
SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE13 (mSPL13)
5
microRNA

• 21-24nt in length
• Gene regulation at the mRNA level

www.qiagen.com/about/PressReleases/images/9.jpg
6
microRNA
7
microRNA mutation
Mutation
mRNA
Hypothesis SPL13 needs to be down regulated by
microRNA156 to maintain normal developmental
program for germination or seedling
establishment.
8
Overaccumulation of SPL13
WT Cont mSPL13
SPL13
rRNA
9
Mutant Phenotype
Cot
Cot
4 leaf seedling (normal)
10
Developmental Delay
2-leaf seedlings
4-leaf seedlings
11
Temporal Seedling Arrest
12
Shoot Apical Meristem (SAM)
0 d
13
Storage Protein and Meristem
Hypocotyl
Radical
14
Meristem Development
15
Visible Difference
mSPL13
WT
8 d
16
Analysis
WT
mSPL13
SPL13
Based on phenotype, down regulation of SPL13 via
microRNA is essential for proper meristem
development.
17
Determine Potential Targets of SPL13
miRNA156
SPL13
SPL13
18
Acknowledgements
Hiro Nonogaki Kevin Ahern Howard Hughes Medical
Institute
Lab Members Masa Asahina Tammy Chan Po-Pu Liu
Jessica Kristof Piotr Pupel Jing Sun
19
SBP1
SBP2
SPL13
?
SQUAMOSA ( or APETALA1)
- 455
- 429
SQUA
AP1
- 419
- 393
10 bp conserved stretch
19-mer core seq
20
Normal Embryogenesis in mSPL13
Coppersmith JL, Hewitt JR, Nonogaki H,
unpublished results