Article

The plant-growth-promoting rhizobacterium Paenibacillus polymyxa induces changes in Arabidopsis thaliana gene expression: a possible connection between biotic and abiotic stress responses.

Department of Microbiology, SLU (Swedish University of Agricultural Sciences), Uppsala, Sweden.
Molecular Plant-Microbe Interactions (Impact Factor: 4.46). 12/1999; 12(11):951-9. DOI: 10.1094/MPMI.1999.12.11.951
Source: PubMed

ABSTRACT This paper addresses changes in plant gene expression induced by inoculation with plant-growth-promoting rhizobacteria (PGPR). A gnotobiotic system was established with Arabidopsis thaliana as model plant, and isolates of Paenibacillus polymyxa as PGPR. Subsequent challenge by either the pathogen Erwinia carotovora (biotic stress) or induction of drought (abiotic stress) indicated that inoculated plants were more resistant than control plants. With RNA differential display on parallel RNA preparations from P. polymyxa-treated or untreated plants, changes in gene expression were investigated. From a small number of candidate sequences obtained by this approach, one mRNA segment showed a strong inoculation-dependent increase in abundance. The corresponding gene was identified as ERD15, previously identified to be drought stress responsive. Quantification of mRNA levels of several stress-responsive genes indicated that P. polymyxa induced mild biotic stress. This suggests that genes and/or gene classes associated with plant defenses against abiotic and biotic stress may be co-regulated. Implications of the effects of PGPR on the induction of plant defense pathways are discussed.

1 Bookmark
 · 
115 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: PR1 gene induction was monitored by RT-PCR in three different grapevine cultures that were inoculated with Plasmopara viticola as a host pathogen and Pseudoperonos-pora cubensis as a non-host pathogen. The results of the expression analysis showed that the PR1 mRNA level in Vitis vinifera cv. Riesling and Vitis riparia cv. Gloire de Montpellier is mainly affected by the culture system. PR1 is constitutively expressed in callus cultures. In vitro plants showed a low basal expression of PR1 that is enhanced af-ter challenge with both downy mildews in the two species tested. In greenhouse plants, PR1 is only expressed 24 h post inoculation (hpi) but not 12 hpi. Heavily infected leaves ('oilspots') of the susceptible cv. Riesling, exhibiting well developed infection structures in the intercellular space as indicated by microscopical methods, also showed a high PR1 expression rate three weeks post inoculation. Thus, the role of PR1 expression in impeding the downy mildew pathogen remains equivocal. It seems that expression of PR1 is a general stress response in some grapevine cul-ture systems and that their use as a reference for gene expression analysis is limited. K e y w o r d s : Downy mildew, Pseudoperonospora cubensis, Plasmopara viticola, RT-PCR, Vitis.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Current agricultural production methods, for example the improper use of chemical fertilizers and pesticides, create many health and environmental problems. Use of plant growth-promoting bacteria (PGPB) for agricultural benefits is increasing worldwide and also appears to be a trend for the future. There is possibility to develop microbial inoculants for use in agricultural biotechnology, based on these beneficial plant-microbe interactions. For this study, ten bacterial strains were isolated from Yongin forest soil for which in vitro plant-growth promoting trait screenings, such as indole acetic acid (IAA) production, a phosphate solubilization test, and a siderophore production test were used to select two PGPB candidates. Arabidopsis thaliana plants were inoculated with Paenibacillus yonginensis DCY84T and Micrococcus yunnanensis PGPB7. Salt stress, drought stress and heavy metal (aluminum) stress challenges indicated that P.yonginensis DCY84T-inoculated plants were more resistant than control plants. AtRSA1, AtVQ9 and AtWRKY8 were used as the salinity responsive genes. The AtERD15, AtRAB18, and AtLT178 were selected to check A.thaliana responses to drought stress. Aluminum stress response was checked using AtAIP, AtALS3 and AtALMT1. The qRT-PCR results indicated that P.yonginensis DCY84T can promote plant tolerance against salt, drought, and aluminum stress. P.yonginensis DCY84T also showed positive results during in vitro compatibility testing and virulence assay against X.oryzae pv. oryzae Philippine race 6 (PXO99). Better germination rates and growth parameters were also recorded for the P.yonginensis DCY84T Chuchung cultivar rice seed which was grown on coastal soil collected from Suncheon. Based on these results, P.yonginensis DCY84T can be used as a promising PGPB isolate for crop improvement.
    Microbiological Research 01/2015; · 1.94 Impact Factor
  • Source
    Eco-friendly Innovative Approaches in Plant Disease Managements, 2012 edited by Vaibhav K. Singh, Yogendra Singh, Akhilesh Singh, 12/2012: chapter 13: pages 207-240; INTERNATIONAL BOOK DISTRIBUTORS, Dehradun- 248 001. (Uttarakhand), India., ISBN: I SBN 8 1 7 0 8 9 3 7 5 - 5

Full-text (2 Sources)

Download
139 Downloads
Available from
May 17, 2014