Transcriptional responses to polycyclic aromatic hydrocarbon-induced stress in Arabidopsis thaliana reveal the involvement of hormone and defense signaling pathways
Creators: name: Weisman, David
name: Alkio, Merianne
name: Colón-Carmona, Adan
Publisher: name: London : BioMed Central Ltd.
Year: 2010
Subjects: subject: Arabidopsis
subject: Arabidopsis thaliana
subject: 1 aminocyclopropanecarboxylic acid
subject: 1-aminocyclopropane-1-carboxylic acid
subject: amino acid
subject: beta glucuronidase
subject: ethylene
subject: ethylene derivative
subject: phenanthrene
subject: phenanthrene derivative
subject: phytohormone
subject: polycyclic aromatic hydrocarbon
subject: article
subject: Botrytis
subject: cluster analysis
subject: DNA microarray
subject: drug effect
subject: gene expression profiling
subject: gene expression regulation
subject: genetic database
subject: genetic transcription
subject: genetics
subject: histology
subject: immunology
subject: metabolism
subject: microbiology
subject: mutation
subject: photoperiodicity
subject: physiological stress
subject: plant growth
subject: plant root
subject: reporter gene
subject: signal transduction
subject: transgenic plant
subject: Amino Acids, Cyclic
subject: Cluster Analysis
subject: Databases, Genetic
subject: Ethylenes
subject: Gene Expression Profiling
subject: Gene Expression Regulation, Plant
subject: Genes, Reporter
subject: Glucuronidase
subject: Hypocotyl
subject: Mutation
subject: Oligonucleotide Array Sequence Analysis
subject: Phenanthrenes
subject: Photoperiod
subject: Plant Growth Regulators
subject: Plant Roots
subject: Plants, Genetically Modified
subject: Polycyclic Hydrocarbons, Aromatic
subject: Signal Transduction
subject: Stress, Physiological
subject: Transcription, Genetic
subject: Dewey Decimal Classification::500 | Naturwissenschaften
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie

description: Background: Polycyclic aromatic hydrocarbons (PAHs) are toxic, widely-distributed, environmentally persistent, and carcinogenic byproducts of carbon-based fuel combustion. Previously, plant studies have shown that PAHs induce oxidative stress, reduce growth, and cause leaf deformation as well as tissue necrosis. To understand the transcriptional changes that occur during these processes, we performed microarray experiments on Arabidopsis thaliana L. under phenanthrene treatment, and compared the results to published Arabidopsis microarray data representing a variety of stress and hormone treatments. In addition, to probe hormonal aspects of PAH stress, we assayed transgenic ethylene-inducible reporter plants as well as ethylene pathway mutants under phenanthrene treatment.Results: Microarray results revealed numerous perturbations in signaling and metabolic pathways that regulate reactive oxygen species (ROS) and responses related to pathogen defense. A number of glutathione S-transferases that may tag xenobiotics for transport to the vacuole were upregulated. Comparative microarray analyses indicated that the phenanthrene response was closely related to other ROS conditions, including pathogen defense conditions. The ethylene-inducible transgenic reporters were activated by phenanthrene. Mutant experiments showed that PAH inhibits growth through an ethylene-independent pathway, as PAH-treated ethylene-insensitive etr1-4 mutants exhibited a greater growth reduction than WT. Further, phenanthrene-treated, constitutive ethylene signaling mutants had longer roots than the untreated control plants, indicating that the PAH inhibits parts of the ethylene signaling pathway.Conclusions: This study identified major physiological systems that participate in the PAH-induced stress response in Arabidopsis. At the transcriptional level, the results identify specific gene targets that will be valuable in finding lead compounds and engineering increased tolerance. Collectively, the results open a number of new avenues for researching and improving plant resilience and PAH phytoremediation.