Scientists Identify Genes Responsible for Mediating Phytohormones

Scientists from the North Carolina State University and Palacky University in Czech Republic have identified a group of genes that mediate plant hormone functions. The researchers studied auxin and ethylene, two of the most important  plant growth-regulating hormones. Ethylene is responsible for disease or wounding resistance, leaf and flower senescence, leaf abscission, fruit ripening and seed germination among other plant physiological processes. Scientists have previously established that plants respond differently to ethylene, depending on its developmental stage and the surrounding environmental conditions.

By studying Arabidopsis mutants, the scientists identified the gene TAA1 responsible for insensitivity to ethylene treatment. TAA1 recognizes the presence of ethylene as its “trigger” to make proteins that in turn synthesize the hormone auxin. Auxin plays an essential role in the coordination of numerous plant growth and behavioral processes. They also identified two related genes, which when silenced result to plants producing 50 percent less auxin  than normal. A clear understanding on how hormones interact with each other may pave the way for the development of plants that are well adapted to extreme environmental conditions like drought and high soil salinity.

The paper published by the journal Cell is available at http://www.cell.com/content/article/fulltext?uid=PIIS0092867408002122 For more information read http://news.ncsu.edu/news/2008/04/tp-alonso.php