title: The THO/TREX Complex Active in miRNA Biogenesis Negatively Regulates Root-Associated Acid Phosphatase Activity Induced by Phosphate Starvation.
abstract: Induction and secretion of acid phosphatases (APases) is an adaptive response that plants use to cope with P (Pi) deficiency in their environment. The molecular mechanism that regulates this response, however, is poorly understood. In this work, we identified an Arabidopsis (Arabidopsis thaliana) mutant, hps8, which exhibits enhanced APase activity on its root surface (also called root-associated APase activity). Our molecular and genetic analyses indicate that this altered Pi response results from a mutation in the AtTHO1 gene that encodes a subunit of the THO/TREX protein complex. The mutation in another subunit of this complex, AtTHO3, also enhances root-associated APase activity under Pi starvation. In Arabidopsis, the THO/TREX complex functions in mRNA export and miRNA biogenesis. When treated with Ag(+), an inhibitor of ethylene perception, the enhanced root-associated APase activity in hps8 is largely reversed. hpr1-5 is another mutant allele of AtTHO1 and shows similar phenotypes as hps8 ein2 is completely insensitive to ethylene. In the hpr1-5ein2 double mutant, the enhanced root-associated APase activity is also greatly suppressed. These results indicate that the THO/TREX complex in Arabidopsis negatively regulates root-associated APase activity induced by Pi starvation by inhibiting ethylene signaling. In addition, we found that the miRNA399-PHO2 pathway is also involved in the regulation of root-associated APase activity induced by Pi starvation. These results provide insight into the molecular mechanism underlying the adaptive response of plants to Pi starvation.
authors.affiliation: MOE Key Laboratory of Bioinformatics, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Sibo
authors.initials: S
authors.lastname: Tao
authors.affiliation: MOE Key Laboratory of Bioinformatics, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: MOE Key Laboratory of Bioinformatics, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Xiaoyue
authors.initials: X
authors.lastname: Wang
authors.affiliation: MOE Key Laboratory of Bioinformatics, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Le
authors.initials: L
authors.lastname: Xu
authors.affiliation: MOE Key Laboratory of Bioinformatics, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Fang
authors.affiliation: MOE Key Laboratory of Bioinformatics, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Zhi John
authors.initials: ZJ
authors.lastname: Lu
authors.affiliation: MOE Key Laboratory of Bioinformatics, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China liu-d@mail.tsinghua.edu.cn.
authors.forename: Dong
authors.identifier: 0000-0002-4679-3515
authors.initials: D
authors.lastname: Liu
mesh_terms: D000135:Acid Phosphatase / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D035683:MicroRNAs / Q000096:biosynthesis*; D046912:Multiprotein Complexes / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D010710:Phosphates / Q000172:deficiency* / Q000494:pharmacology; D018517:Plant Roots / Q000033:anatomy & histology / Q000201:enzymology* / Q000235:genetics*; D021122:Protein Subunits / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D029681:Arabidopsis Proteins; C552050:EMU protein, Arabidopsis; D005030:Ethylenes; D035683:MicroRNAs; D046912:Multiprotein Complexes; D010710:Phosphates; D021122:Protein Subunits; C036216:ethylene; D000135:Acid Phosphatase