Biotech Updates

Mastermind Steroid Found in Plants

November 26, 2010

Scientists have been aware of the importance of plant steroids called brassinosteroids in the regulation of plant growth and development. However, they still lack information about the extent of these steroids' reach. Scientists Yu Sun and Zhi-Yong Wang of Carnegie Institute of Washington have discovered about a thousand brassinosteroid target genes, "which reveal molecular links between the steroid and numerous cellular functions and other hormonal and light-activated chain reactions." This study is the first detailed action map for a plant hormone that will help advance plant science and crop research.

Steroids are important hormones in animals and plants. However, plants do not have glands that secrete these hormones so each cell has the ability to produce hormones. Based on previous studies, brassinosteroids function in environmental stress acclimation, cell elongation, and improve resistance to pathogens, thus increasing plant growth and crop yield. The extent of its function has not been revealed because of the lack of knowledge on target genes.

"We performed a genome-wide analysis of genes that are direct targets of brassinosteroid in the model plant Arabidopsis, a relative of mustard." explained coauthor Yu Sun. "We identified DNA sequences in the genome where a transcription factor resides—that is a protein that begins the process of turning a gene on or off. We were very surprised by the large number of genes involved. Arabidopsis has about 32,000 genes in total and this hormone appears to be masterminding a lot of different physiological responses."

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