IC4R002-miRNA-2011-21679406

Project Title

Deep sequencing on genome-wide scale reveals the unique composition and expression patterns of microRNAs in developing pollen of Oryza sativa

The Background of This Project

[[File:|700px|thumb|right|Figure 1. GWA Analysis of Al Tolerance within and across Rice Subpopulations.]]

• Pollen development in flowering plants requires strict control of the gene expression program and genetic information stability by mechanisms possibly including the miRNA pathway. However, our understanding of the miRNA pathway in pollen development remains limited, and the dynamic profile of miRNAs in developing pollen is unknown.
• MicroRNAs (miRNAs) and small interfering RNAs (siRNAs) are two types of small non-coding RNAs (20 to 24 nucleotides in length) identified in nearly all eukaryotes.

The pool of small RNAs in plants is highly complex, consisting primarily of many low-abundant siRNAs and a small number of highly expressed 21-nucleotide sequences; most of the latter are miRNAs [1,2]. Most miRNA loci are encoded by independent transcriptional units in intergenic regions that are transcribed by RNA polymerase II. In plants, miRNAs are processed from stem-loop regions of long primary transcripts by a Dicer-like enzyme and are loaded into silencing complexes, where they generally direct cleavage of complementary mRNAs. Although miRNAs were identified in plants just recently, studies have revealed that miRNAs play crucial roles in each major stage of plant development, often targeting the transcription factors that mediate transition from one developmen-tal stage to the next.

Research Findings

[[File:|700px|thumb|right|Figure 2. Haplotype analysis of the Nrat1 gene region.]]

Corresponding Author

• Susan R. McCouch(srm4@cornell.edu)