Washington: Cornell University researchers have proved a theory of how several plants transport sugars from their leaves to flowers, roots, fruits, and other parts of their structure.
Robert Turgeon, Cornell professor of plant biology who first proposed the theory of transporting sugar in 1991, said his team used genetic engineering techniques to prove his theory, known as the polymer trap model.
The researchers say their findings may help deepen the understanding of basic plant biology. They also say these findings may be critically important in an era of climate change because they may one day allow researchers to genetically engineer plants with increased photosynthetic rates, yields and carbon dioxide intake.
According to Mr. Turgeon’s theory, upon accumulation in leaves as a product of photosynthesis, sucrose diffuses into the plant’s tubelike transport tissue called phloem along with other nutrients to move to other areas of the plant.
In the phloem, small molecules of sucrose combine to form larger and more complex sugars, which become too large to flow back into the leaf. The sugars thus produced are then forced to move away from the leaf to parts of the plant where they may be used or stored.
Mr. Turgeon worked with Dr. Ashlee McCaskill to prove this theory.
They genetically engineered a plant closely related to a member of the figwort family, purple mullein (Verbascum phoeneceum L.) to silence two genes involved in combining sucrose into larger molecules.
When the researchers did so, sugars backed up in the leaves.
Dr. McCaskill said in normal plants, when sugars made from water and carbon dioxide accumulate in the leaves, photosynthesis slows down, and the plant does not take in as much carbon dioxide from the air. — ANI
