ARS | Publication request: The microRNA156 and microRNA172 gene regulation cascades at post-germinative stages in Arabidopsis

Submitted to: Seed Science Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 27, 2010
Publication Date: June 15, 2010
Citation: Martin, R.C., Asahina, M., Liu, P., Kristof, J.R., Coppersmith, J.L., Pluskota, W.E., Bassel, G.W., Goloviznina, N.A., Nguyen, T.T., Nonogaki, H., Pupel, P. 2010. The microRNA156 and microRNA172 gene regulation cascades at post-germinative stages in Arabidopsis. Seed Science Research. 20:79-87.

Interpretive Summary: MicroRNAs (miRNAs) are small RNAs that are involved in the regulation of plant development. Germination and early seedling development are critical for successful stand establishment. A young seedling consist of mainly embryo derived tissues until the formation of the first true leaves. This switch to vegetative growth is a significant transition during the early stages of plant development. When the down regulation of SQUAMOSAPROMOTER-BINDING PROTEIN-LIKE13 by miR156 was interrupted, there was a delay in seedling development indicating that this down regulation is important for normal plant development. This delay in seedling development may be related to the up regulation of another miRNA, miR172 suggesting the interaction of two miRNA pathways.

Technical Abstract: MicroRNAs (miRNAs) are involved in developmental programs of plants including seed germination and post-germination. Here, we provide evidence that two different miRNA pathways, miR156 and miR172, interact during the post-germination stages in Arabidopsis. Mutant seedlings expressing miR156resistant SQUAMOSA-PROMOTER-BINDING PROTEIN-LIKE13 (mSPL13), which has silent mutations in the miR156 complementary sequence, over-accumulated SPL13 mRNA and exhibited a delay in seedling development. Microarray analysis indicated that SCHNARCHZAPFEN (SNZ), an AP-2 like gene targeted by miR172, was down-regulated in these mutants. Quantitative RT-PCR and miRNA gel blot analyses showed that the MIR172 genes were up-regulated in mSPL13 mutants. These results suggest that the miRNA regulation cascades (miR156'SPL13 _ miR172 _SNZ) play a critical role during the post-germination developmental stages in Arabidopsis.