It was already known that miR319-regulated transcription factors affect the growth of leaves. Using a combination of biochemical and genetic analyses, the researchers have now discovered that the transcription factors also regulate those genes that are essential for the formation of the plant hormone jasmonic acid. The higher the amount of microRNA miR319 present in the plant, the lower the number of transcription factors that are produced. This results in smaller amounts of jasmonic acid which can be synthesized. Plants containing little jasmonic acid age more slowly: The leaves become yellow and the plant dies. This process can be stopped by treating the plant with the hormone.
"Our studies show that the transcription factors, which are regulated by the microRNA miR319, exert a negative influence on the growth of plants, and also lead to premature aging. The mechanism discovered here is a further milestone in the attempt to explain the relationships of genetic regulation in plants. Only when we have a better understanding of these processes will we be able to produce plants that have particularly desired properties," says Detlef Weigel, who heads the project.
|Contact: Dr. Detlef Weigel|