A new study published in the open-access journal PLoS Biology finds that slower growing plants stay fresh longer. Detlef Weigel (Max Planck Institute for Developmental Biology, Tubingen, Germany) and colleagues came to this conclusion after analyzing genes called microRNAs that coordinate the growth and aging processes in plants.

Production of a plant hormone called jasmonic acid is influenced when microRNAs inhibit certain regulators known as TCP transcription factors. As the number of microRNAs increases, there are fewer active transcription factors and plant produces a smaller amount of jasmonic acid. Jasmonic acid is an important part of the plant aging process, and the plant grows more slowly if there is less of it. Researchers can use genetic methods to control the quantity of microRNAs in plants and thus can control the amount of jasmonic acid. In the future, agriculturalists may be able to cultivate longer-living and faster-growing plants.

Short, single-stranded RNA molecules, microRNAs regulate other genes by binding to complementary sections of the genetic material and preventing them from being used to synthesize gene products. MicroRNAs in plants chiefly inhibit other regulators called transcription factors. By binding to DNA sections, these transcription factors can switch genes on or off; hence, the activation or blocking allows plants to either increase or decrease the number of proteins produced. Any imbalance will lead to a visible change in the plant because proteins control metabolic processes.

Weigel and colleagues used the plant Arabidopsis thaliana to investigate the effects on growth an aging due to transcription factors of the TCP family. The transcription factors are regulated by the microRNA miR319.

“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,” informs Weigel. Their findings add to the research efforts that are attempting to explain how plants are genetically regulated.

Control of jasmonate biosynthesis and senescence by miR319 targets
Schommer C, Palatnik JF, Aggarwal P, Chetelat A, Cubas P, et al.
PLoS Biology (2008). 6(9): e230.
doi:10.1371/journal.pbio.0060230
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About PLoS Biology

PLoS Biology is an open-access, peer-reviewed general biology journal published by the Public Library of Science (PLoS), a nonprofit organization of scientists and physicians committed to making the world’s scientific and medical literature a public resource. New articles are published online weekly; issues are published monthly. For more information, visit http://www.plosbiology.org

About the Public Library of Science

The Public Library of Science (PLoS) is a non-profit organization of scientists and physicians committed to making the world’s scientific and medical literature a freely available public resource. For more information, visit http://www.plos.org

Written by: Peter M Crosta