Publications by authors named "Anhui Wu"

7 Publications

  • Page 1 of 1

Autoregulation of RCO by Low-Affinity Binding Modulates Cytokinin Action and Shapes Leaf Diversity.

Curr Biol 2019 12 21;29(24):4183-4192.e6. Epub 2019 Nov 21.

Department of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829 Cologne, Germany. Electronic address:

Mechanisms through which the evolution of gene regulation causes morphological diversity are largely unclear. The tremendous shape variation among plant leaves offers attractive opportunities to address this question. In cruciferous plants, the REDUCED COMPLEXITY (RCO) homeodomain protein evolved via gene duplication and acquired a novel expression domain that contributed to leaf shape diversity. However, the molecular pathways through which RCO regulates leaf growth are unknown. A key question is to identify genome-wide transcriptional targets of RCO and the DNA sequences to which RCO binds. We investigate this question using Cardamine hirsuta, which has complex leaves, and its relative Arabidopsis thaliana, which evolved simple leaves through loss of RCO. We demonstrate that RCO directly regulates genes controlling homeostasis of the hormone cytokinin to repress growth at the leaf base. Elevating cytokinin signaling in the RCO expression domain is sufficient to both transform A. thaliana simple leaves into complex ones and partially bypass the requirement for RCO in C. hirsuta complex leaf development. We also identify RCO as its own target gene. RCO directly represses its own transcription via an array of low-affinity binding sites, which evolved after RCO duplicated from its progenitor sequence. This autorepression is required to limit RCO expression. Thus, evolution of low-affinity binding sites created a negative autoregulatory loop that facilitated leaf shape evolution by defining RCO expression and fine-tuning cytokinin activity. In summary, we identify a transcriptional mechanism through which conflicts between novelty and pleiotropy are resolved during evolution and lead to morphological differences between species.
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http://dx.doi.org/10.1016/j.cub.2019.10.040DOI Listing
December 2019

Salt stress and senescence: identification of cross-talk regulatory components.

J Exp Bot 2014 Jul 6;65(14):3993-4008. Epub 2014 May 6.

University of Potsdam, Institute of Biochemistry and Biology, Karl-Liebknecht-Straße 24-25, Haus 20, D-14476 Potsdam-Golm, Germany Max-Planck Institute of Molecular Plant Physiology, Plant Signaling Group, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany

Leaf senescence is an active process with a pivotal impact on plant productivity. It results from extensive signalling cross-talk coordinating environmental factors with intrinsic age-related mechanisms. Although many studies have shown that leaf senescence is affected by a range of external parameters, knowledge about the regulatory systems that govern the interplay between developmental programmes and environmental stress is still vague. Salinity is one of the most important environmental stresses that promote leaf senescence and thus affect crop yield. Improving salt tolerance by avoiding or delaying senescence under stress will therefore play an important role in maintaining high agricultural productivity. Experimental evidence suggests that hydrogen peroxide (H2O2) functions as a common signalling molecule in both developmental and salt-induced leaf senescence. In this study, microarray-based gene expression profiling on Arabidopsis thaliana plants subjected to long-term salinity stress to induce leaf senescence was performed, together with co-expression network analysis for H2O2-responsive genes that are mutually up-regulated by salt induced- and developmental leaf senescence. Promoter analysis of tightly co-expressed genes led to the identification of seven cis-regulatory motifs, three of which were known previously, namely CACGTGT and AAGTCAA, which are associated with reactive oxygen species (ROS)-responsive genes, and CCGCGT, described as a stress-responsive regulatory motif, while the others, namely ACGCGGT, AGCMGNC, GMCACGT, and TCSTYGACG were not characterized previously. These motifs are proposed to be novel elements involved in the H2O2-mediated control of gene expression during salinity stress-triggered and developmental senescence, acting through upstream transcription factors that bind to these sites.
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http://dx.doi.org/10.1093/jxb/eru173DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4106443PMC
July 2014

Design and synthesis of N-aryl isothioureas as a novel class of gastric H(+) /K(+) -ATPase inhibitors.

Arch Pharm (Weinheim) 2013 Dec 30;346(12):891-900. Epub 2013 Oct 30.

Key Laboratory of Structure-Based Drugs Design and Discovery of Ministry of Education, School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang, P. R. China.

To find new H(+) /K(+) -ATPase inhibitors for the treatment of peptic ulcer disease, a series of novel N-aryl isothiourea derivatives were synthesized and their structures were identified by (1) H NMR and GC-MS. The effects of these compounds on inhibiting gastric acid secretion were evaluated by the guinea pig stomach mucous membrane study with pantoprazole magnesium as a positive control. The results showed that, of the 37 N-aryl isothiourea compounds synthesized, 20 compounds have comparable or stronger gastric acid inhibitory activities than that of pantoprazole magnesium. The quantitative structure-activity relationships (QSARs) of the N-aryl isothiourea compounds were also studied by comparative molecular field analysis (CoMFA) computation, and the model structure that was supposed to give more powerful bioactivities was finally predicted.
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http://dx.doi.org/10.1002/ardp.201300276DOI Listing
December 2013

Synthesis of -labelled oxidized metabolites of the carcinogenic polycyclic aromatic hydrocarbon benzo[]pyrene.

Tetrahedron 2012 Sep;68(35)

The Ben May Department for Cancer Research, The University of Chicago, Chicago, IL 60637, United States.

Polycyclic aromatic hydrocarbons (PAHs), such as benzo[]pyrene (BP), are ubiquitous environmental contaminants that are implicated in causing lung cancer. BP is a component of tobacco smoke that is transformed enzymatically to active forms that interact with DNA. We reported previously development of a sensitive stable isotope dilution LC/MS method for analysis of BP metabolites. We now report efficient syntheses of -BP and the complete set of its -labelled oxidized metabolites needed as internal standards They include the metabolites not involved in carcinogenesis () and the metabolites implicated in initiation of cancer (). The synthetic approach is novel, entailing use of Pd-catalyzed Suzuki, Sonogashira, and Hartwig cross-coupling reactions combined with PtCl-catalyzed cyclization of acetylenic compounds. This synthetic method requires fewer steps, employs milder conditions, and product isolation is simpler than conventional methods of PAH synthesis. The syntheses of -BP and -BP-8-ol each require only four steps, and the -atoms are all introduced in a single step. -BP-8-ol serves as the synthetic precursor of all the oxidized metabolites of -BP implicated in initiation of cancer. The isotopic purities of the synthetic -BP metabolites were estimated to be ≥99.9%.
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http://dx.doi.org/10.1016/j.tet.2012.05.130DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3826453PMC
September 2012

JUNGBRUNNEN1, a reactive oxygen species-responsive NAC transcription factor, regulates longevity in Arabidopsis.

Plant Cell 2012 Feb 17;24(2):482-506. Epub 2012 Feb 17.

University of Potsdam, Institute of Biochemistry and Biology, 14476 Potsdam-Golm, Germany.

The transition from juvenility through maturation to senescence is a complex process that involves the regulation of longevity. Here, we identify JUNGBRUNNEN1 (JUB1), a hydrogen peroxide (H(2)O(2))-induced NAC transcription factor, as a central longevity regulator in Arabidopsis thaliana. JUB1 overexpression strongly delays senescence, dampens intracellular H(2)O(2) levels, and enhances tolerance to various abiotic stresses, whereas in jub1-1 knockdown plants, precocious senescence and lowered abiotic stress tolerance are observed. A JUB1 binding site containing a RRYGCCGT core sequence is present in the promoter of DREB2A, which plays an important role in abiotic stress responses. JUB1 transactivates DREB2A expression in mesophyll cell protoplasts and transgenic plants and binds directly to the DREB2A promoter. Transcriptome profiling of JUB1 overexpressors revealed elevated expression of several reactive oxygen species-responsive genes, including heat shock protein and glutathione S-transferase genes, whose expression is further induced by H(2)O(2) treatment. Metabolite profiling identified elevated Pro and trehalose levels in JUB1 overexpressors, in accordance with their enhanced abiotic stress tolerance. We suggest that JUB1 constitutes a central regulator of a finely tuned control system that modulates cellular H(2)O(2) level and primes the plants for upcoming stress through a gene regulatory network that involves DREB2A.
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http://dx.doi.org/10.1105/tpc.111.090894DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3315228PMC
February 2012

Salt-triggered expression of the ANAC092-dependent senescence regulon in Arabidopsis thaliana.

Plant Signal Behav 2010 Jun 1;5(6):733-5. Epub 2010 Jun 1.

University of Potsdam, Institute of Biochemistry and Biology, Potsdam-Golm, Germany.

The NAC domain transcription factor ANAC092 plays a central role in leaf senescence in Arabidopsis thaliana. We recently identified 170 genes whose expression increases upon activation of ANAC092 in a chemically (estradiol) controlled experimental set-up, 78 of which are known senescence-associated genes (SAGs). In accordance with the well-known phenomenon that salt stress promotes early leaf senescence in many plant species, we previously observed salt stress-enhanced expression of many SAGs of the ANAC092 regulon. Global expression profiling now revealed that 36 genes, representing 46% of all ANAC092 downstream SAGs, are induced by long-term (4 days) salt stress in shoots of Arabidopsis, whereas short-term stress (6 hours) only slightly affects gene expression. Expression analysis also showed that 14 of the 36 genes are induced by hydrogen peroxide (H2O2) treatment. Additionally, 15 senescence-associated NAC genes (senNACs), including ANAC092, respond to H2O2 exposure. Our data support the model that salt-triggered senescence is at least partly mediated through the ANAC092 gene regulatory network. Other senNACs most likely contribute to the coordination of this process, potentially in concert with H2O2-mediated signaling.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3001574PMC
http://dx.doi.org/10.4161/psb.5.6.11694DOI Listing
June 2010

Regiospecific oxidation of polycyclic aromatic phenols to quinones by hypervalent iodine reagents.

Tetrahedron 2010 Mar;66(12):2111-2118

Ben May Department for Cancer Research, Gordon Center for Integrative Sciences, University of Chicago, 929 East 57th Street, Room W308, Chicago, IL 60637, USA.

The hypervalent iodine reagents -iodoxybenzoic acid (IBX) and bis(trifluoro-acetoxy)iodobenzene (BTI) are shown to be general reagents for regio-controlled oxidation of polycyclic aromatic phenols (PAPs) to specific isomers (, , or remote) of polycyclic aromatic quinones (PAQs). The oxidations of a series of PAPs with IBX take place under mild conditions to furnish the corresponding -PAQs. In contrast, oxidations of the same series of PAPs with BTI exhibit variable regiospecificity, affording -PAQs where structurally feasible and -PAQs or remote PAQ isomers in other cases. The structures of the specific PAQ isomers formed are predictable on the basis of the inherent regioselectivities of the hypervalent iodine reagents in combination with the structural requirements of the phenol precursors. IBX and BTI are recommended as the preferred reagents for regio-controlled oxidation of PAPs to PAQs.
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http://dx.doi.org/10.1016/j.tet.2009.12.022DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3762479PMC
March 2010