China News Service, Hefei, March 22 (Reporter Wu Lan) Sun Linfeng's team from the University of Science and Technology of China recently made breakthrough progress in the transportation field of the sixth largest plant hormone, brassinosteroid, and discovered the first brassinosteroid. transport proteins and find the "secret channel" for their transport.
On March 22, the authoritative international journal Science published this research result. It is reported that since the discovery of brassinosteroids more than 80 years ago, its transportation process has been an unsolved mystery.
Schematic diagram of brassinosteroid transport. (Photo courtesy of University of Science and Technology of China)
In daily life, tunnels can help people cross mountains and ridges. In plant cells, when internal substances pass through the cell membrane, they often pass through similar "tunnels." While studying the transport of auxin, the first major type of plant hormone, Sun Linfeng's team made an unexpected discovery.
"The ABCB19 protein is widely recognized as an auxin transport protein. The mutated protein means that the function is damaged, that is, it can no longer transport auxin. However, we found that the appearance characteristics of plants with this protein mutation are similar to those of other auxin transport proteins. The mutants did not behave exactly the same, so we wondered whether this protein also transports other plant hormones?" The team members examined the protein's response to other plant hormones and finally discovered the transport process of brassinosteroids.
According to reports, the ABCB19 protein looks like a V-shaped clip with two openings. It is a small "tunnel" swimming on the cell membrane. The inverted V-shaped opening "captures" the brassinosteroid inside the cell. After binding, it is then A positive V-shaped opening is opened outside the cell for "release".
Sun Linfeng's team also collaborated with Eugenia Rasinova's team at Ghent University, Belgium, and confirmed that ABCB19 protein can transport brassinosteroids in plant cells.
Cartoon diagram of brassinosteroid transport mechanism. (Produced by Qie Mingqing)
"It is an interesting discovery that ABCB19 protein can transport brassinosteroids, and the team has made a significant contribution to research in this field." The reviewer commented.
"ABCB19 belongs to a class of 'family proteins' with similar structures and functions. The discovery of its 'hidden function' provides new ideas for our subsequent research." Sun Linfeng said. In the future, further functional analysis and transformation of this family of proteins will provide more help for people to understand and utilize brassinosteroid signaling to promote agricultural production.
It is reported that in 1996, the academic community listed brassinosteroids as the sixth largest class of plant hormones after auxin, abscisic acid, cytokinins, ethylene and gibberellins. (over)