Researchers find hormones that ripen grapes

Based on their ripening patterns and physiological differences, fruits can be categorized as climacteric or non-climacteric. The first class encompasses fruits which have a well-characterized peak of the hormone ethylene during the onset of ripening, and includes fruits such as tomatoes, apples, and bananas. The second class, on the other hand, includes species such as citrus, strawberries, grapes, and other fruits whose ripening processes are not well understood. The ripening process is important to food supply, nutrition, and health, and controlling it may allow fruits to be transported without worry that they will be bruised or damaged. How this process occurs in grape is explored in “Grapes on Steroids. Brassinosteroids Are Involved in Grape Berry Ripening,” an article by Gregory M. Symons, of the University of Tasmania, and colleagues. Their work is published in the latest issue of Plant Physiology. By isolating the genes coding for steroidal hormones known as brassinosteroids (BRs), and the receptors for their gene products, researchers confirmed that the grape brassinosteroid-6-oxidase gene is involved in the grape ripening process. They also found that applying BRs to grape berries (cv. Cabernet Sauvignon) significantly promoted ripening, while brassinazole, an inhibitor of BR biosynthesis, significantly delayed fruit ripening. Previous research has shown that BRs are essential for normal plant growth and development, but they have not hitherto been found to be involved in ripening. The new findings can aid scientists in their work on improving grapes, and can likewise allow researchers a deeper understanding of how ripening can be controlled in other important non-climacteric fruits. "Source":[ http://www.checkbiotech.org/root/index.cfm?fuseaction=news&doc_id=12127&start=21&control=218&page_start=1&page_nr=101&pg=1]

---