Crop Biotech Update

microRNA159 Impacts Multiple Agronomic Traits in Rice

November 22, 2017

The miR159 is a conserved microRNA (miRNA) among different plant species and has various development functions in plants. In rice, studies on miR159 were focused upon responses to nitrogen forms and abiotic stresses. The team of Yafan Zhao and Huili Wen from Henan Agricultural University aim to study the function of miR159 using Short Tandem Target Mimic (STTM), an effective tool to block the activity of endogenous mature miRNA activity in plants.

The expression of miR159 was successfully suppressed by STTM, resulting in the increased expressions of its two target genes, OsGAMYB and OsGAMYBL1. The STTM159 plants exhibited short stature with smaller organ sizes as well as decreases in stem diameter, length of flag leaf, main panicle, spikelet hulls and grain size. Analysis showed a reduction in the number of small vascular bundles (SVB), and less cell numbers in the outer parenchyma.

Meanwhile, analysis of differentially expressed genes between wild type plants and STTM159 transgenic plants showed that genes involved in cell division, auxin, cytokinin and brassinosteroids biosynthesis and signaling are significantly downregulated in STTM159 plants.

These data suggest that miR159 positively regulates organ size via the promotion of cell division.

For more on this study, read the article in BMC Plant Biology.