title: Light influences how the fungal toxin deoxynivalenol affects plant cell death and defense responses.
abstract: The Fusarium mycotoxin deoxynivalenol (DON) can cause cell death in wheat (Triticum aestivum), but can also reduce the level of cell death caused by heat shock in Arabidopsis (Arabidopsis thaliana) cell cultures. We show that 10 μg mL(-1) DON does not cause cell death in Arabidopsis cell cultures, and its ability to retard heat-induced cell death is light dependent. Under dark conditions, it actually promoted heat-induced cell death. Wheat cultivars differ in their ability to resist this toxin, and we investigated if the ability of wheat to mount defense responses was light dependent. We found no evidence that light affected the transcription of defense genes in DON-treated roots of seedlings of two wheat cultivars, namely cultivar CM82036 that is resistant to DON-induced bleaching of spikelet tissue and cultivar Remus that is not. However, DON treatment of roots led to genotype-dependent and light-enhanced defense transcript accumulation in coleoptiles. Wheat transcripts encoding a phenylalanine ammonia lyase (PAL) gene (previously associated with Fusarium resistance), non-expressor of pathogenesis-related genes-1 (NPR1) and a class III plant peroxidase (POX) were DON-upregulated in coleoptiles of wheat cultivar CM82036 but not of cultivar Remus, and DON-upregulation of these transcripts in cultivar CM82036 was light enhanced. Light and genotype-dependent differences in the DON/DON derivative content of coleoptiles were also observed. These results, coupled with previous findings regarding the effect of DON on plants, show that light either directly or indirectly influences the plant defense responses to DON.
authors.affiliation: Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, 4 Blackfan Circle, Boston, MA 02115, USA. kansari@partners.org.
authors.forename: Khairul I
authors.initials: KI
authors.lastname: Ansari
authors.affiliation: Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences (SLU), Umeå 90 183, Sweden. Siamsa.Doyle@slu.se.
authors.forename: Siamsa M
authors.initials: SM
authors.lastname: Doyle
authors.affiliation: UCD Earth Institute and School of Biology and Environmental Science, College of Science, University College Dublin, Belfield, Dublin 4, Ireland. jkacprzyk@gmail.com.
authors.forename: Joanna
authors.initials: J
authors.lastname: Kacprzyk
authors.affiliation: Institute of Advanced Study in Science and Technology, Guwahati-35, India. mrk6@rediffmail.com.
authors.forename: Mojibur R
authors.initials: MR
authors.lastname: Khan
authors.affiliation: Department of Integrated Pest Management, Research Centre Flakkebjerg, Forsøgsvej 1, Slagelse DK-4200, Denmark. stephanie-walter@gmx.net.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Walter
authors.affiliation: Plant Health Laboratory, Department of Agriculture and Food, Backweston, Co. Kildare, Ireland:. josephine.brennan@agriculture.gov.ie.
authors.forename: Josephine M
authors.initials: JM
authors.lastname: Brennan
authors.affiliation: UCD Earth Institute and School of Biology and Environmental Science, College of Science, University College Dublin, Belfield, Dublin 4, Ireland. chansundar@yahoo.com.
authors.forename: Chanemouga Soundharam
authors.initials: CS
authors.lastname: Arunachalam
authors.affiliation: UCD Earth Institute and School of Biology and Environmental Science, College of Science, University College Dublin, Belfield, Dublin 4, Ireland. paul.mccabe@ucd.ie.
authors.forename: Paul F
authors.initials: PF
authors.lastname: McCabe
authors.affiliation: UCD Earth Institute and School of Biology and Environmental Science, College of Science, University College Dublin, Belfield, Dublin 4, Ireland. Fiona.doohan@ucd.ie.
authors.forename: Fiona M
authors.initials: FM
authors.lastname: Doohan
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000187:drug effects* / Q000528:radiation effects*; D002470:Cell Survival / Q000187:drug effects; D005670:Fusarium; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005838:Genotype; D006358:Hot Temperature; D008027:Light; D010935:Plant Diseases; D036226:Seedlings / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D014255:Trichothecenes / Q000494:pharmacology / Q000633:toxicity*; D014908:Triticum / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*
chemical_list: D014255:Trichothecenes; C007262:deoxynivalenol