Retrotransposon and gene activation in wheat in response to mycotoxigenic and non-mycotoxigenic-associated Fusarium stress.
Despite inhibition of protein synthesis being its mode of action, the trichothecene mycotoxin deoxynivalenol (DON) induced accumulation of transcripts encoding translation elongation factor 1alpha (EF-1alpha), class III plant peroxidase (POX), structure specific recognition protein, basic leucine zipper protein transcription factor (bZIP), retrotransposon-like homologs and genes of unknown function in the roots of wheat cultivars CM82036 and Remus. Fusarium head blight (FHB) studies using Fusarium graminearum and its trichothecene-minus (Tri5 ( - )) mutant derivative and adult plant DON tests showed that these transcripts were responsive to both mycotoxigenic- and non-mycotoxigenic-associated Fusarium stress. In tests using the parents 'CM82036', 'Remus' and 14 double-haploid progeny that segregated for quantitative trait locus (QTL) Fhb1 on chromosome 3BS (syn. Qfhs.ndsu-3BS) (from 'CM82036' that confers DON tolerance), bZIP expression was significantly more DON-up-regulated in lines that inherited this QTL. Basal accumulation of the bZIP transcript in spikelets treated with Tween20 (control), DON and in DON-relative to Tween20-treated spikelets was negatively correlated with DON-induced bleaching above (but not below) the treated spikelets (AUDPC(DON)) (r = -0.41, -0.75 and -0.72, respectively; P < or = 0.010). bZIP-specific PCR analysis of 'Chinese spring' and its 3BS deletion derivatives indicated that bZIP is located in chromosomal region(s) other than 3BS. These results, and the fact that a homologous cold-regulated wheat bZIP (wLIP19) maps to group 1 chromosomes suggests that wheat bZIP may participate in defence response cascades associated with Fhb1 and that there is a cross-talk between biotic and abiotic stress signalling pathways.
Ansari
Khairul I
KI
Molecular Plant-Microbe Interactions Laboratory, School of Biology and Environmental Sciences, College of Life Sciences, University College Dublin, Belfield, Dublin 4, Ireland. khairul.ansari@ucd.ie
Walter
Stephanie
S
Brennan
Josephine M
JM
Lemmens
Marc
M
Kessans
Sarah
S
McGahern
Angela
A
Egan
Damian
D
Doohan
Fiona M
FM
D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D005670:Fusarium / Q000472:pathogenicity*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D018626:Retroelements / Q000235:genetics; D015533:Transcriptional Activation; D014255:Trichothecenes / Q000633:toxicity; D014908:Triticum / Q000187:drug effects / Q000235:genetics* / Q000382:microbiology*; D014774:Virulence
D017931:DNA Primers; D018744:DNA, Plant; D018626:Retroelements; D014255:Trichothecenes; C007262:deoxynivalenol