"Nature": How does auxin quickly promote cell growth

TMK-mediated cell membrane growth hormone-induced cell elongation mechanism model image courtesy of Fujian Agriculture and Forestry University

Auxin is phosphorylated by TMK and activates the proton pump (H+-ATPase) to cause acidification and elongation of the cell wall.
Photo courtesy of Fujian Agriculture and Forestry University

On October 27th, the Joint Center of Horticultural Biology and Metabolomics of Fujian Agriculture and Forestry University-University of California, Riverside published a research article entitled "TMK Kinase Mediates Cell Surface Growth Hormone Signaling to Activate Cell Wall Acidification" in Nature
.

This work revealed that plants sense extracellular growth hormone through the cell membrane surface receptor-like kinase family protein (TMK), and activate the proton pump (H+-ATPase) on the cell membrane surface through specific phosphorylation, leading to acidification of the cell wall and promoting cell elongation And tissue growth
.

Auxin is the first hormone found in plants and is named because it promotes growth
.

With the discovery and analysis of the auxin signaling pathway mediated by the receptor-like kinase TMK family, the all-round regulation mode of auxin from the cell membrane to the nucleus provides new ideas for the interpretation of the complex functions of auxin, and also for unlocking the auxin The acid growth hypothesis provides a new strategy
.

The research team from Fujian Agriculture and Forestry University-University of California Joint Center found that receptor-like kinases (TMK1) and multiple members of the proton pump family (H+-ATPase, AHAs) located on the cell membrane can specifically bind to protein profiles by immunoprecipitation.

.

Using plant hypocotyl cell elongation as a research model, the study found that in TMK deletion mutants, auxin cannot promote cell elongation
.

This research reveals how plants can quickly respond to extracellular growth hormone signals to induce protein binding and modification to activate proton pumps, induce acidification of cell walls, and promote cell elongation and tissue growth.
On the other hand, from molecular mechanisms It is a very important breakthrough in the field of auxin to truly analyze the formation mechanism of the "cell acidification theory" at the level
.

The research was completed by the Fujian Agriculture and Forestry University-University of California, Riverside Joint Center, and Dr.
Lin Wenwei from the center was the first author
.

Related paper information: https://doi.