MicroRNA 157 Regulates Floral Organs Development and Ovule Production in Cotton

In cotton (Gossypium hirsutum), some miRNAs have been characterized in floral organ development, a crucial factor for cotton yield. Huazhong Agricultural University scientists, led by Nian Liu, studied the role of miRNA156/157 in floral organ development in cotton.

The team overexpressed both miRNA precursors in cotton to unveil their function. Overexpression of the GhmiRNA157 precursor resulted in smaller floral organs, fewer ovules, and decreased seed production. This was due to the suppression of cell proliferation and cell elongation.

Further analysis revealed that five SQUAMOSA promoter-binding protein-like (SPL) genes were the targets of the GhmiRNA157, as proven by the decreased expression levels of these GhSPLs in the miR157- overexpressing lines. Two MADS-box genes, associated with floral organ development and reproductive production, were also repressed in the miR157-overexpressing lines. Furthermore, auxin-inducible genes were also down-regulated, and auxin signaling was eased in the miR157-overexpressing lines.

These results indicate that the GhmiR157 controls floral organ growth and ovule production by regulating MADS-box genes and auxin signal transduction. This study can be a basis for improvement of cotton yield.

For more information, read the article in BMC Plant Biology.