Plants let chloroplasts know the time
University of Bristol
15 March 2013Plant cells communicate information about the time of day to their chloroplasts, the part of their cells that underpins all agricultural productivity on Earth, researchers at the University of Bristol have demonstrated in a study published today in Science.
Plant cells contain an internal clock (the circadian clock), which is able to regulate cellular processes so that they occur at the optimal time of day, causing a big increase in plant productivity. As chloroplasts are the site of photosynthesis, their function is highly dependent on the daily changes in light environment.
It is thought that chloroplasts were originally free-living organisms that were incorporated into the cells of plants very early in plant evolutionary history. A result of this is that chloroplasts have retained some of the cellular machinery required to produce proteins from their own chloroplast DNA. An essential part of this machinery are ‘sigma factors’, and in present-day plants, they are encoded for by the cell’s nuclear DNA.
The researchers were able to show that the production of sigma factors is controlled by the plant’s clock. This enables the nuclear DNA to regulate the activity of chloroplast genes, and ensure that the production of proteins essential for photosynthesis is co-ordinated with daylight.
Dr Antony Dodd of Bristol’s School of Biological Sciences said: “This is a major breakthrough that provides a completely new perspective on daily circadian rhythms. We have learnt from this work that timing information moves between different parts of the cell, and in particular involves the chloroplast, which is the part of the cell that underpins all agricultural productivity on the planet. It’s particularly fascinating that the process we identified makes use of genes that pre-date modern land plants and originates from the bacteria that gave rise to chloroplasts.”
Australia OGTR to Issue License for Controlled Release of GM Wheat and Barley<http://www.isaaa.org/kc/cropbiotechupdate/article/default.asp?ID=10774>The Gene Technology Regulator decided to issue a license to authorize the limited and controlled release (field trial) of genetically modified wheat <http://www.isaaa.org/resources/publications/pocketk/38/default.asp> and barley lines with altered grain composition and nutrient utilization efficiency. The release is planned to take place at one site per growing season in the local government area of Narrabri (NSW), between May 2013 and April 2016. The three-year field trial is aimed to assess plant biomass and yield, grain protein composition, dough making properties, and end product quality.For details of this news, see http://www.ogtr.gov.au/internet/ogtr/publishing.nsf/Content/dir117.
Created May 30, 2013 | Category: Growing Knowledge