Heat Resistance in Plants Found
By Kim Tong-hyung
Staff Reporter
Researchers are claiming advancement in the genetic engineering of plants to improve heat tolerance, which is increasingly critical in the global efforts to combat desertification.
In a study published by peer-review journal Proceedings of the National Academy of Sciences (PNAS), a team led by Gyeongsang National University scientist Lee Sang-yeol found that controlling the expression of AtTDX, a plant-specific protein, may provide a key in genetically-engineering plans against high-temperature stress.
According to the researchers, heat-shock causes AtTDX to convert from a lower molecular weight (LMW) form to high molecular weight (HMW) form, gaining a more heat-stable structure.
The transition in structure also brings changes in the protein's activities, Lee said. In the LMW form, AtTDX functions mainly as a disulfide reductase, while in the HMW complexes, the proteins predominately function as chaperones, or heat-shock proteins expressed in response to elevated temperatures or other cellular stresses.
The over-expression of AtTDX had been linked to enhanced heat-shock resistance in plants, primarily through its chaperone activity, Lee said.
``Think of it as the relationship between Super Man and Clark Kent. The AtTDX, a plant-specific thioredoxin (Trx)-like protein, usually functions as a disulfide reductase, but is added with the ability as a chaperone under stress to protect the plant,'' said Lee.
``The finding adds detail to the knowledge of the mechanism of how plants gain heat tolerance, which may open new opportunities in developing plants with better heat resistance,'' he said.
Researchers around the world have been concentrating on developing plants that could thrive in harsh, high-temperature conditions, which is becoming crucial amid the increasing effects of desertification and global warming.
In most studies, high-temperature tolerance in plants has been engineered by over-expressing the heat-shock protein genes.