Discover the mechanism of temporal control of plant growth

Researchers at the Institute of Molecular and Cellular Biology of Plants IBMCP, joint center of the Polytechnic University of Valencia and the Consejo Superior de Investigaciones Cientificas CSIC, have elucidated the mechanism that regulates the growth of plants by time of day.

The results of this investigation, obtained in collaboration with researchers from the University of California, suggest that in the future it may subtly change the pattern of plant growth to increase or reduce its size. This discovery is published in the prestigious U.S. journal Proceedings of the National Academy of Sciences PNAS, and could have long-term agronomic applications, such as growing grain, as well as energy production through biomass.

The life of animals and plants follows a daily temporal pattern adapted to the normal cycles of light and darkness imposed by the rotation of the Earth. Plants do not grow continuously throughout the day, but preferably concentrate growth at the end of the night and early in the day, then spend the remaining time to carry out photosynthesis and reallocation of energy resources generated.

Miguel Blazquez, CSIC researcher and member of one of the newly formed microclusters of VLC / CAMPUS, explains that "it is known that the rhythmic pattern of daily growth depends on the operation of an internal clock to have all plant cells, and is known also long known that some hormones, gibberellins, are essential for plant cells to expand. However, it was not known until now how to couple the clock and gibberellins to generate a robust pattern of growth. "

One way imaginable to coordinate orders with gibberellins clock would make the synthesis of gibberellins clock activity. That is, the synthesis of gibberellins follow a rhythmic pattern consistent with the peak of growth in this way, at certain times of day gibberellins synthesized more than others, and the accumulation of gibberellins peaks correspond to times of maximum growth . However, the research team led by the CSIC has found an alternative.

"Actually, the clock determines the presence of gibberellin receptors in cells oscillate rhythmically, with minimal during the day and peak during the night. In this way, plants are more sensitive to gibberellins at the end of the night, the signaling pathway activated right then, and then when plants grow, "says Miguel Blazquez.

A control point for growth

One of the most striking results describing the research is that a mutant plant in which gibberellin signaling pathway is active permanently lose the rhythmic control of growth: it grows continuously throughout the day, and the final size plants is also higher. This observation suggests a possible point of control over that influence to change the time pattern of plant growth, given that the ability to perceive the gibberellins varies throughout the day.

The researchers' work also shows that the coupling between the clock and sensitivity to gibberellin is closer than it was suspected at first. "Not only determines the rate of growth, but extends to other processes in which the plant must respond to environmental stimuli, including abiotic stressors.

Many of the genes that are activated in response to external aggressions have a daily oscillation, and we find that this rate is determined by gibberellins "concludes Dr. Blazquez. This research is an important step in understanding the control mechanisms plant growth, and could be a future breakthrough for agriculture.

Bibliographic information:
Maria Veronica Arana, Nora de la Rosa Marin, Julin N. Maloof, Miguel A. Blazquez, and David Alabadi. Circadian oscillation of gibberellin signaling in Arabidopsis. Institute of Plant Molecular and Cellular Biology, Consejo Superior de Investigaciones Científicas-Universidad Politecnica de Valencia, 46022 Valencia, Spain, and Department of Plant Biology, University of California, Davis, CA 95616. DOI: 10.1073/pnas. 1101050108

Source: SINC