RT Journal Article
SR Electronic
T1 Regulation of Aluminum Resistance in Arabidopsis Involves the SUMOylation of the Zinc Finger Transcription Factor STOP1
JF The Plant Cell
JO Plant Cell
FD American Society of Plant Biologists
SP tpc.00687.2020
DO 10.1105/tpc.20.00687
A1 Fang, Qiu
A1 Zhang, Jie
A1 Zhang, Yang
A1 Fan, Ni
A1 van den Burg, Harrold A.
A1 Huang, Chao-Feng
YR 2020
UL http://www.plantcell.org/content/early/2020/11/06/tpc.20.00687.abstract
AB Aluminum (Al) is a primary constraint for crop production on acid soils, which make up more than 30% of the arable land in the world. Al resistance in Arabidopsis is achieved by malate secretion mediated by the AtALMT1 transporter. The C2H2-type transcription factor STOP1 is essential and required for Al resistance, where it acts by inducing the expression of Al-resistance genes, including AtALMT1. In this study, we describe that STOP1 protein function is modified by SUMOylation. The SUMO protease ESD4, but not other SUMO proteases, specifically interacts with and deSUMOylates STOP1. Mutation of ESD4 increases the level of STOP1 SUMOylation and the expression of STOP1-regulated gene AtALMT1, which contributes to the increased Al resistance in esd4. The esd4 mutation does not influence STOP1 protein abundance, but increases the association of STOP1 with the AtALMT1 promoter, which might be the reason for the elevated expression of AtALMT1 in esd4. We demonstrate that STOP1 is mono-SUMOylated at K40, K212, or K395 sites, and blocking of STOP1 SUMOylation reduces STOP1 stability and the expression of STOP1-regulated genes, leading to the reduced Al resistance. Our results thus reveal the involvement of SUMOylation in the regulation of STOP1 and Al resistance in Arabidopsis.