TY - JOUR
T1 - The rhizobacterial elicitor acetoin induces systemic resistance in Arabidopsis thaliana
AU - Rudrappa, Thimmaraju
AU - Biedrzycki, Meredith L.
AU - Kunjeti, Sridhara G.
AU - Donofrio, Nicole M.
AU - Czymmek, Kirk J.
AU - Paré, Paul W.
AU - Bais, Harsh P.
N1 - Funding Information:
Our in vivo pathogenicity assay results showed a significantly reduced disease incidence, symptom development and DC3000 multiplication in the leaves of B. subtilis root colonized plants. The data mainly indicated that this protection is brought about by the reduced proliferation of the pathogen in the inoculated leaves of the B. subtilis root inoculated plants. This was supported by the significantly lower DC3000 CFUs per gram fresh weight of the inoculated leaves in the case of B. subtilis treated plants. However, like previous studies42,43-48 and our study, the introduction of B. subtilis and challenging plants with P. syringae are spatially separated. This ruled out the possibility of direct effect of acetoin on DC3000 by contact, and demonstrated that the effect was plant mediated. Additionally, exposing the plants uniformly with acetoin also ensured that the effect was systemic and not local. Although, previous studies showed a successful protection of plants from root fungal infections49,50 and aerial feeding by beetles46no effort has been made to study the effect of B. subtilis induced ISR on the aerial bacterial infections in A. thaliana.
PY - 2010/3
Y1 - 2010/3
N2 - The majority of plant growth promoting rhizobacteria (PGPR) confer plant immunity against a wide range of foliar diseases by activating plant defences that reduce a plant's susceptibility to pathogen attack. Here we show that Arabidopsis thaliana (Col-0) plants exposed to Bacillus subtilis strain FB17 (hereafter FB17), results in reduced disease severity against Pseudomonas syringae pv. tomato DC3000 (hereafter DC3000) compared to plants without FB17 treatment. Exogenous application of the B. subtilis derived elicitor, acetoin (3-hydroxy-2-butanone), was found to trigger induced systemic resistance (ISR) and protect plants against DC3000 pathogenesis. Moreover, B. subtilis acetoin biosynthetic mutants that emitted reduced levels of acetoin conferred reduced protection to A. thaliana against pathogen infection. Further analysis using FB17 and defense-compromised mutants of A. thaliana indicated that resistance to DC3000 occurs via NPR1 and requires salicylic acid (SA)/ethylene (ET) whereas jasmonic acid (JA) is not essential. This study provides new insight into the role of rhizo-bacterial volatile components as elicitors of defense responses in plants.
AB - The majority of plant growth promoting rhizobacteria (PGPR) confer plant immunity against a wide range of foliar diseases by activating plant defences that reduce a plant's susceptibility to pathogen attack. Here we show that Arabidopsis thaliana (Col-0) plants exposed to Bacillus subtilis strain FB17 (hereafter FB17), results in reduced disease severity against Pseudomonas syringae pv. tomato DC3000 (hereafter DC3000) compared to plants without FB17 treatment. Exogenous application of the B. subtilis derived elicitor, acetoin (3-hydroxy-2-butanone), was found to trigger induced systemic resistance (ISR) and protect plants against DC3000 pathogenesis. Moreover, B. subtilis acetoin biosynthetic mutants that emitted reduced levels of acetoin conferred reduced protection to A. thaliana against pathogen infection. Further analysis using FB17 and defense-compromised mutants of A. thaliana indicated that resistance to DC3000 occurs via NPR1 and requires salicylic acid (SA)/ethylene (ET) whereas jasmonic acid (JA) is not essential. This study provides new insight into the role of rhizo-bacterial volatile components as elicitors of defense responses in plants.
KW - Acetoin
KW - Arabidopsis thaliana
KW - Bacillus
KW - Defense response
KW - Salicylic acid
UR - http://www.scopus.com/inward/record.url?scp=77956136372&partnerID=8YFLogxK
U2 - 10.4161/cib.3.2.10584
DO - 10.4161/cib.3.2.10584
M3 - Article
C2 - 20585504
AN - SCOPUS:77956136372
VL - 3
SP - 130
EP - 138
JO - Communicative and Integrative Biology
JF - Communicative and Integrative Biology
SN - 1942-0889
IS - 2
ER -