TITLE:
Evaluation of a Brassica napus Auxin-Repressed Gene Induced by Flea Beetle Damage and Sclerotinia sclerotiorum Infection
AUTHORS:
Limin Wu, Min Yu, Jennifer Holowachuk, Andrew Sharpe, Derek Lydiate, Dwayne Hegedus, Margaret Gruber
KEYWORDS:
BnARP, Brassica napus, Flea Beetle, S. sclerotiorum
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.8 No.8,
July
27,
2017
ABSTRACT: Biotic
stresses negatively affect canola growth and production. Flea beetle damage and Sclerotinia sclerotiorum (S. sclerotiorum)
infection are two of the worst biotic stresses for canola. Auxin Repressed Proteins (ARPs)
responsive to several abiotic stresses have been reported. However, information
about ARPs induced by Flea beetle damage and S. sclerotiorum infection, their roles in biotic stress tolerance are still lacking in canola.
ESTs for an Auxin Repressed Protein 1 (BnARP1) were
highly represented (expressed) in a Brassica napus subtractive library developed after leaf damage by the crucifer flea beetle (Phyllotreta cruciferae).
Expression of this gene was under different developmental control in B. napus, and
it was co-induced in B. napus by
flea beetle feeding, S. sclerotiorum infection, drought and cold. A total of 25 BnARP genes
were represented in different B. napus stress
and development EST libraries and indicated larger, diversified families than
known earlier. Dwarf phenotypes, primary root growth inhibition, lateral root
enhancement, reduced sensitivity to 2, 4-D, and reduced PIN1 and LOX expression in transgenic Arabidopsis expression lines suggest that BnARP1 is an
auxin repressor that prevents auxin transport and supports an interaction
between the auxin and jasmonate signalling pathways. And the increased survival
after S. sclerotiorum infection in transgenic over-expression Arabidopsis suggests that BnARP1 could
play a role in S. sclerotiorum tolerance through connecting auxin and jasmonate signalling pathways.