The role of phytohormones in basal resistance and Trichoderma-induced systemic resistance to Botrytis cinerea in Arabidopsis thaliana

Pseudomonas fluorescens strains that produce the polyketide antibiotic 2,4-diacetylphloroglucinol (2,4-DAPG) are among the most effective rhizobacteria that suppress root and crown rots, wilts, and damping-off diseases of a variety of crops, and they play a key role in the natural suppressiveness of some soils to certain soilborne pathogens. Root colonization by 2,4-DAPG-producing P. fluorescens strains Pf-5 (genotype A), Q2-87 (genotype B), Q8r1-96 (genotype D), and HT5-1 (genotype N) produced induced systemic resistance (ISR) in Arabidopsis thaliana accession Col-0 against bacterial speck caused by P. syringae pv. tomato. The ISR-eliciting activity of the four bacterial genotypes was similar, and all genotypes were equivalent in activity to the well-characterized strain P. fluorescens WCS417r. The 2,4-DAPG biosynthetic locus consists of the genes phlHGF and phlACBDE. phlD or phlBC mutants of Q2-87 (2,4-DAPG minus) were significantly reduced in ISR activity, and genetic complementation of the mutants restored ISR activity back to wild-type levels. A phlF regulatory mutant (overproducer of 2,4-DAPG) had ISR activity equivalent to the wild-type Q2-87. Introduction of DAPG into soil at concentrations of 10 to 250 μM 4 days before challenge inoculation induced resistance equivalent to or better than the bacteria. Strain Q2-87 induced resistance on transgenic NahG plants but not on npr1-1, jar1, and etr1 Arabidopsis mutants. These results indicate that the antibiotic 2,4-DAPG is a major determinant of ISR in 2,4-DAPG-producing P. fluorescens, that the genotype of the strain does not affect its ISR activity, and that the activity induced by these bacteria operates through the ethylene- and jasmonic acid-dependent signal transduction pathway.

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The role of ethylene in rhizobacteria-induced systemic resistance (ISR)

Advances in Plant Ethylene Research ◽

10.1007/978-1-4020-6014-4_73 ◽

2007 ◽

pp. 325-331 ◽

Cited By ~ 6

Author(s):

C. M. J. Pieterse ◽

S. Van Der Ent ◽

J. A. Van Pelt ◽

L. C. Van Loon

Keyword(s):

Induced Systemic Resistance ◽

Systemic Resistance

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The Possible Role of PR Proteins in Multigenic and Induced Systemic Resistance

Multigenic and Induced Systemic Resistance in Plants ◽

10.1007/0-387-23266-4_6 ◽

2006 ◽

pp. 112-142 ◽

Cited By ~ 9

Author(s):

Sadik Tuzun ◽

Aravind Somanchi

Keyword(s):

Induced Systemic Resistance ◽

Pr Proteins ◽

Systemic Resistance

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The role of salicylic acid in induced systemic resistance elicited by plant growth-promoting rhizobacteria against blue mold of tobacco

Biological Control ◽

10.1016/s1049-9644(02)00108-1 ◽

2002 ◽

Vol 25 (3) ◽

pp. 288-296 ◽

Cited By ~ 101

Author(s):

Shouan Zhang ◽

Anne-Laure Moyne ◽

M.S Reddy ◽

Joseph W Kloepper

Keyword(s):

Salicylic Acid ◽

Plant Growth ◽

Induced Systemic Resistance ◽

Plant Growth Promoting Rhizobacteria ◽

Systemic Resistance ◽

Blue Mold ◽

Plant Growth Promoting ◽

Growth Promoting

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Induced Systemic Resistance in Arabidopsis thaliana in Response to Root Inoculation with Pseudomonas fluorescens CHA0

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2003.16.10.851 ◽

2003 ◽

Vol 16 (10) ◽

pp. 851-858 ◽

Cited By ~ 283

Author(s):

Annalisa Iavicoli ◽

Emmanuel Boutet ◽

Antony Buchala ◽

Jean-Pierre Métraux

Keyword(s):

Arabidopsis Thaliana ◽

Jasmonic Acid ◽

Pseudomonas Fluorescens ◽

Transgenic Line ◽

Induced Systemic Resistance ◽

Antibiotic Activity ◽

Systemic Resistance ◽

Peronospora Parasitica ◽

Molecular Processes ◽

Molecular Determinants

Root inoculation of Arabidopsis thaliana ecotype Columbia with Pseudomonas fluorescens CHA0r partially protected leaves from the oomycete Peronospora parasitica. The molecular determinants of Pseudomonas fluorescens CHA0r for this induced systemic resistance (ISR) were investigated, using mutants derived from strain CHA0: CHA400 (pyoverdine deficient), CHA805 (exoprotease deficient), CHA77 (HCN deficient), CHA660 (pyoluteorin deficient), CHA631 (2,4-diacetylphloroglucinol [DAPG] deficient), and CHA89 (HCN, DAPG- and pyoluteorin deficient). Only mutations interfering with DAPG production led to a significant decrease in ISR to Peronospora parasitica. Thus, DAPG production in Pseudomonas fluorescens is required for the induction of ISR to Peronospora parasitica. DAPG is known for its antibiotic activity; however, our data indicate that one action of DAPG could be due to an effect on the physiology of the plant. DAPG at 10 to 100 μM applied to roots of Arabidopsis mimicked the ISR effect. CHA0r-mediated ISR was also tested in various Arabidopsis mutants and transgenic plants: NahG (transgenic line degrading salicylic acid [SA]), sid2-1 (nonproducing SA), npr1-1 (non-expressing NPR1 protein), jar1-1 (insensitive to jasmonic acid and methyl jasmonic acid), ein2-1 (insensitive to ethylene), etr1-1 (insensitive to ethylene), eir1-1 (insensitive to ethylene in roots), and pad2-1 (phytoalexin deficient). Only jar1-1, eir1-1, and npr1-1 mutants were unable to undergo ISR. Sensitivity to jasmonic acid and functional NPR1 and EIR1 proteins were required for full expression of CHA0r-mediated ISR. The requirements for ISR observed in this study in Peronospora parasitica induced by Pseudomonas fluorescens CHA0r only partially overlap with those published so far for Peronospora parasitica, indicating a great degree of flexibility in the molecular processes leading to ISR.

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Function of miR825 and miR825* as Negative Regulators in Bacillus cereus AR156-elicited Systemic Resistance to Botrytis cinerea in Arabidopsis thaliana

International Journal of Molecular Sciences ◽

10.3390/ijms20205032 ◽

2019 ◽

Vol 20 (20) ◽

pp. 5032 ◽

Cited By ~ 5

Author(s):

Pingping Nie ◽

Chen Chen ◽

Qian Yin ◽

Chunhao Jiang ◽

Jianhua Guo ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Bacillus Cereus ◽

Botrytis Cinerea ◽

Target Genes ◽

Interactive Effect ◽

Defense Responses ◽

Northern Blotting ◽

Systemic Resistance ◽

Negative Regulators ◽

Callose Deposition

Small RNAs function to regulate plant defense responses to pathogens. We previously showed that miR825 and miR825* downregulate Bacillus cereus AR156 (AR156)-triggered systemic resistance to Pseudomonassyringae pv. tomato DC3000 in Arabidopsis thaliana (Arabidopsis). Here, Northern blotting revealed that miR825 and miR825* were more strongly downregulated in wild type Arabidopsis Col-0 (Col-0) plants pretreated with AR156 than in nontreated plants upon Botrytis cinerea (B. cinerea) B1301 infection. Furthermore, compared with Col-0, transgenic plants with attenuated miR825 and miR825* expression were more resistant to B. cinerea B1301, yet miR825- and miR825*-overexpressing (OE) plants were more susceptible to the pathogen. With AR156 pretreatment, the transcription of four defense-related genes (PR1, PR2, PR5, and PDF1.2) and cellular defense responses (hydrogen peroxide production and callose deposition) were faster and stronger in miR825 and miR825* knockdown lines but weaker in their OE plants than in Col-0 plants upon pathogen attack. Also, AR156 pretreatment caused stronger phosphorylation of MPK3 and MPK6 and expression of FRK1 and WRKY53 genes upon B. cinerea B1301 inoculation in miR825 and miR825* knockdown plants than in Col-0 plants. Additionally, the assay of agrobacterium-mediated transient co-expression in Nicotiana benthamiana confirmed that AT5G40910, AT5G38850, AT3G04220, and AT5G44940 are target genes of miR825 or miR825*. Compared with Col-0, the target mutant lines showed higher susceptibility to B. cinerea B1301, while still expressing AR156-triggered induced systemic resistance (ISR). The two-way analysis of variance (ANOVA) revealed a significant (P < 0.01) interactive effect of treatment and genotype on the defense responses. Hence, miR825 and miR825*act as negative regulators of AR156-mediated systemic resistance to B. cinerea B1301 in Arabidopsis.

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Effects of postharvest methyl jasmonate treatments against Botrytis cinerea on Geraldton waxflower (Chamelaucium uncinatum)

Australian Journal of Experimental Agriculture ◽

10.1071/ea04250 ◽

2006 ◽

Vol 46 (5) ◽

pp. 717 ◽

Cited By ~ 8

Author(s):

J. X. Eyre ◽

J. Faragher ◽

D. C. Joyce ◽

P. R. Franz

Keyword(s):

Methyl Jasmonate ◽

Botrytis Cinerea ◽

Induced Systemic Resistance ◽

Floral Organ ◽

Ethylene Biosynthesis ◽

Systemic Resistance ◽

Meja Treatment ◽

Flower Abscission ◽

Chamelaucium Uncinatum

Cut Geraldton waxflower (Chamelaucium uncinatum Schauer) flowers are often infected with Botrytis cinerea. Release of infection from quiescence can cause ethylene production by invaded host tissues and result in flower abscission. Postharvest floral organ abscission is a major problem for the commercial waxflower industry. Methyl jasmonate (MeJA) occurs naturally in plant tissue and has a signalling role in eliciting induced systemic resistance against disease. MeJA treatments have been shown to suppress B. cinerea infecting cut rose flowers. The present experiments investigated the potential of exogenous MeJA treatments for B. cinerea management on harvested waxflower. MeJA treatments of 10 and 100 µL liquid MeJA/L of air applied to cv. Purple Pride and 1 µL MeJA/L to cv. Mullering Brook gave reductions in disease severity for uninoculated stems. However, concentrations of 100 µL MeJA/L applied to Purple Pride in addition to 1 and 10 µL MeJA/L applied to Mullering Brook increased the incidence of floral organ fall. Flower abscission upon treatment with MeJA may be due to induced systemic resistance-associated upregulation of ethylene biosynthesis. MeJA treatments had no direct effect on B. cinerea hyphal elongation in vitro. Collectively, these results show that while MeJA treatment may elicit defence in waxflower against Botrytis, the chemical also causes floral organ fall. Thus, exogenous MeJA treatments do not have potential for B. cinerea management on harvested waxflower.

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