'How seeds make food, energy early in development decoded'

London, Dec 29 (PTI) When plant seeds came into contact with water, some of their internal chemical processes to make food and energy are established in a matter of minutes, according to a study which may lead to more efficient farming practices.

The researchers, including those from the University of Munster in Germany, said the early growth and development of seeds is controlled by several plant hormones.

While these plant chemicals have been researched intensely, they said, not much is known about the processes that make energy available in the seeds, and those that help efficiently start early food production.

The current study, published in the journal PNAS, assessed both energy metabolism, and the so-called redox chemical pathways, which rely on sulphur.

It revealed the molecules within seeds which are activated to allow energy to be released efficiently, with some controlling molecules in the sulphur redox reactions playing a central role.

As part of the study, the scientists visualised under the microscope the molecule adenosine triphosphate (ATP) -- the general currency for energy in the cell -- and another molecule, Nicotinamide adenine dinucleotide phosphate (NADPH), in the mitochondria.

They compared seeds from thale cress -- both dry seeds and seeds 'imbibed' with water.

To find out whether the redox pathways were important for kick-starting seed development, the team deactivated specific proteins using genetic methods, and then compared the reaction shown by the modified seeds with that of the unmodified ones.

The scientists allowed the seeds to age artificially in the laboratory, and found that the seeds germinated much less actively if they lacked these proteins.

They then examined the relevant redox proteins by isolating active mitochondria, and flash-freezing them in order to study where the process was taking place.

Using biochemical methods, the researchers identified several small proteins important for resource efficiency in energy metabolism.

'The process could be likened to the traffic control system of a large city. Before the rush hour -- i.e germination -- starts, which puts large quantities of metabolites 'on the road', the traffic light and routing systems need to be switched on in the morning; and here this is done by the thiol redox switches,' explained study lead author Thomas Nietzel from the University of Munster.

According to the researchers, the findings could be of relevance in farming, when seeds need to keep their germination vigour for as long as possible on the one hand, but should also germinate with minimal losses.

'By looking into the very early processes of germination control, we can gain a better understanding of the mechanisms driving seed germination. In future we could think about how such switches could be used in crop biotechnology,' said study co-author Markus Schwarzlander from the University of Munster. PTI VIS VIS VIS