Controlling leaf stomatal aperture via abscisic acid transport

June 16, 2021

Functions of two abscisic acid transporters are revealed

A collaborative research team of RIKEN CSRS and the Graduate School of Nara Institute of Science and Technology elucidated a new mechanism that controls transport of the plant hormone abscisic acid (ABA), which induce stomatal closure.

ABA is synthesized mainly in leaf vascular tissues and transported to guard cells. Although multiple proteins that transport ABA into or out of the cells (transporters) have been identified, how the movement of ABA is regulated in plants is not fully understood.

The collaborative team found that NPF4.6 protein that had been previously reported to function as an ABA transporter mediates ABA uptake into leaf guard cells to promote stomatal closure. They further revealed that another protein called NPF5.1 is also an ABA transporter. It was proposed that NPF5.1 facilitates ABA uptake into cells in leaf vascular tissues and mesophyll cells to limit the amount of ABA transported from vascular tissues to guard cells and negatively regulates stomatal closure.

These results will contribute to the development of technology that improves plant drought resistance and productivity by controlling stomatal aperture.

Original article
Genes doi:10.3390/genes12060885
T. Shimizu, Y. Kanno, H. Suzuki, S. Watanabe, M. Seo,
"Arabidopsis NPF4.6 and NPF5.1 Control Leaf Stomatal Aperture by Regulating Abscisic Acid Transport".
Mitsunori Seo
Unit Leader
Dormancy and Adaptation Research Unit