Plants compete for sunlight, finding may help hike yields

Scientists have found molecular details of 'Shade Avoidance Syndrome' (SAS) in plants which will allow them to augment yield of food crops ranging from rice to wheat.

The findings of the research, carried out by scientists at Salk Institute of Biological Studies in California, is expected to play vital role in ensuring food security across the world.

Plants can make out difference between shade of inanimate objects and that of another plant. When they detect competition from other plants to reach out for light, it initiates a set of responses which is collectively called Shade Avoidance Syndrome.

"Plants compete with each other for light, and Shade Avoidance Syndrome has a big ecological and economic impact, especially in the high density plantings typical in modern agriculture," said Joanne Chory of Howard Hughes Medical Institute, who led the study.

The findings, published in April four issue of journal Cell, seem to be even more important in the age of shrinking agricultural lands due to rapid urbanisation.

Plants can sense and response to the presence of other plants in their vicinity by the amount of lights come to them after being reflected by others, they said.

Plants "desperately" try to come out of shade areas and grow towards sunlight, which is driven by a plant hormone Auxin. Scarcity of light may hamper yield of seeds, scientists said.

"To secure their place in the sun, plants direct their growth resources toward stem elongation and away from bulking up harvestable portions such as leaves and seeds," said Chory.

"Suppressing the shade avoidance reaction in crops may allow us to increase biomass and seed yield," she pointed out.

The researchers identified the genes that involved in SAS and examined the responses in details so that scientists can manipulate those.

They examined three dimensional structures of Alliinase, a set of enzymes found in plants like garlic and onion.

The newly discovered structure of enzyme "likely to bind amino acid tryptophan," said Joseph P Noel of J H S Centre for Chemical Biology and Proteomics, who was also participated in the research.

"That's when it became really exciting since we knew that plants can use tryptophan to synthesize Auxin," Noel added.

Despite the importance of Auxin hormone for plant growth and development, details of how it is synthesized, however, continue to puzzle scientists.