Auxin-Regulated Reversible Inhibition of TMK1 Signaling by MAKR2 Modulates the Dynamics of Root Gravitropism

第一作者：Maria Mar Marquès-Bueno

第一单位：法国里昂大学

通讯作者：Yvon Jaillais

 Abstract 

大背景：Plants are able to orient their growth according to gravity, which ultimately controls both shoot and root architecture.

向重力性与生长素：Gravitropism is a dynamic process whereby gravistimulation induces the asymmetric distribution of the plant hormone auxin, leading to asymmetric growth, organ bending, and subsequent reset of auxin distribution back to the original pre-gravistimulation situation.

生长素与PINs：Differential auxin accumulation during the gravitropic response depends on the activity of polarly localized PIN-FORMED (PIN) auxin-efflux carriers.

提出问题：In particular, the timing of this dynamic response is regulated by PIN2, but the underlying molecular mechanisms are poorly understood.

主要发现：Here, we show that MEMBRANE ASSOCIATED KINASE REGULATOR2 (MAKR2) controls the pace of the root gravitropic response.

结果1-MAKR2抑制TMK1信号：We found that MAKR2 is required for the PIN2 asymmetry during gravitropism by acting as a negative regulator of the cell-surface signaling mediated by the receptor-like kinase TRANSMEMBRANE KINASE1 (TMK1).

结果2-可逆抑制：Furthermore, we show that the MAKR2 inhibitory effect on TMK1 signaling is antagonized by auxin itself, which triggers rapid MAKR2 membrane dissociation in a TMK1-dependent manner.

结论：Our findings suggest that the timing of the root gravitropic response is orchestrated by the reversible inhibition of the TMK1 signaling pathway at the cell surface.

doi: 10.1016/j.cub.2020.10.011

Journal: Current Biology

Published date: Nov 05, 2020