AUTHOR=Zhu Ruojia , Dong Xiaoxia , Hao Weiwei , Gao Wei , Zhang Wenzhu , Xia Shuyan , Liu Ting , Shang Zhonglin
TITLE=Heterotrimeric G Protein-Regulated Ca2+ Influx and PIN2 Asymmetric Distribution Are Involved in Arabidopsis thaliana Roots' Avoidance Response to Extracellular ATP
JOURNAL=Frontiers in Plant Science
VOLUME=8
YEAR=2017
URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.01522
DOI=10.3389/fpls.2017.01522
ISSN=1664-462X
ABSTRACT=
Extracellular ATP (eATP) has been reported to be involved in plant growth as a primary messenger in the apoplast. Here, roots of Arabidopsis thaliana seedlings growing in jointed medium bent upon contact with ATP-containing medium to keep away from eATP, showing a marked avoidance response. Roots responded similarly to ADP and bz-ATP but did not respond to AMP and GTP. The eATP avoidance response was reduced in loss-of-function mutants of heterotrimeric G protein α subunit (Gα) (gpa1-1 and gpa1-2) and enhanced in Gα-over-expression (OE) lines (wGα and cGα). Ethylenebis(oxyethylenenitrilo) tetraacetic acid (EGTA) and Gd3+ remarkably suppressed eATP-induced root bending. ATP-stimulated Ca2+ influx was impaired in Gα null mutants and increased in its OE lines. DR5-GFP and PIN2 were asymmetrically distributed in ATP-stimulated root tips, this effect was strongly suppressed by EGTA and diminished in Gα null mutants. In addition, some eATP-induced genes' expression was also impaired in Gα null mutants. Based on these results, we propose that heterotrimeric Gα-regulated Ca2+ influx and PIN2 distribution may be key signaling events in eATP sensing and avoidance response in Arabidopsis thaliana roots.