Auxin Profiling and GmPIN Expression in Phytophthora sojae−Soybean Root Interactions

Auxin (indole-3-acetic acid, IAA) has been implicated as a susceptibility factor in both beneficial and pathogenic molecular plant−microbe interactions. Previous studies have identified a large number of auxin-related genes underlying quantitative disease resistance loci (QDRLs) for Phytophthora sojae. Thus, we hypothesized that auxin may be involved the P. sojae−soybean interaction. The levels of IAA and related metabolites were measured in mycelia and media supernatant as well as in mock and inoculated soybean roots in a time course assay. The expression of 11 soybean Pin-formed (GmPIN) auxin efflux transporter genes was also examined. Tryptophan, an auxin precursor, was detected in the P. sojae mycelia and media supernatant. During colonization of roots, levels of IAA and related metabolites were significantly higher in both moderately resistant Conrad and moderately susceptible Sloan inoculated roots compared with mock controls at 48 h postinoculation (hpi) in one experiment and at 72 hpi in a second, with Sloan accumulating higher levels of the auxin catabolite IAA-Ala than Conrad. Additionally, one GmPIN at 24 hpi, one at 48 hpi, and three at 72 hpi had higher expression in inoculated compared with the mock control roots in Conrad. The ability of resistant cultivars to cope with auxin accumulation may play an important role in quantitative disease resistance. Levels of jasmonic acid (JA), another plant hormone associated with defense responses, were also higher in inoculated roots at these same time points, suggesting that JA also plays a role during the later stages of infection.

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Testing methods and statistical models of genomic prediction for quantitative disease resistance to Phytophthora sojae in soybean [Glycine max (L.) Merr] germplasm collections

Theoretical and Applied Genetics ◽

10.1007/s00122-020-03679-w ◽

2020 ◽

Vol 133 (12) ◽

pp. 3441-3454

Author(s):

William R. Rolling ◽

Anne E. Dorrance ◽

Leah K. McHale

Keyword(s):

Disease Resistance ◽

Glycine Max ◽

Genomic Prediction ◽

Statistical Models ◽

Phytophthora Sojae ◽

Testing Methods ◽

Quantitative Disease Resistance ◽

Germplasm Collections ◽

Glycine Max L

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An efficient direct screening system for microorganisms that activate plant immune responses based on plant–microbe interactions using cultured plant cells

Scientific Reports ◽

10.1038/s41598-021-86560-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Mari Kurokawa ◽

Masataka Nakano ◽

Nobutaka Kitahata ◽

Kazuyuki Kuchitsu ◽

Toshiki Furuya

Keyword(s):

Immune Responses ◽

Plant Defense ◽

Pseudomonas Syringae ◽

Large Scale ◽

Plant Cells ◽

Defense Responses ◽

Root Tip ◽

General Strategy ◽

Plant Defense Responses ◽

Microbe Interactions

AbstractMicroorganisms that activate plant immune responses have attracted considerable attention as potential biocontrol agents in agriculture because they could reduce agrochemical use. However, conventional methods to screen for such microorganisms using whole plants and pathogens are generally laborious and time consuming. Here, we describe a general strategy using cultured plant cells to identify microorganisms that activate plant defense responses based on plant–microbe interactions. Microbial cells were incubated with tobacco BY-2 cells, followed by treatment with cryptogein, a proteinaceous elicitor of tobacco immune responses secreted by an oomycete. Cryptogein-induced production of reactive oxygen species (ROS) in BY-2 cells served as a marker to evaluate the potential of microorganisms to activate plant defense responses. Twenty-nine bacterial strains isolated from the interior of Brassica rapa var. perviridis plants were screened, and 8 strains that enhanced cryptogein-induced ROS production in BY-2 cells were selected. Following application of these strains to the root tip of Arabidopsis seedlings, two strains, Delftia sp. BR1R-2 and Arthrobacter sp. BR2S-6, were found to induce whole-plant resistance to bacterial pathogens (Pseudomonas syringae pv. tomato DC3000 and Pectobacterium carotovora subsp. carotovora NBRC 14082). Pathogen-induced expression of plant defense-related genes (PR-1, PR-5, and PDF1.2) was enhanced by the pretreatment with strain BR1R-2. This cell–cell interaction-based platform is readily applicable to large-scale screening for microorganisms that enhance plant defense responses under various environmental conditions.

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The Leucine-Rich Repeat Domain Can Determine Effective Interaction Between RPS2 and Other Host Factors in Arabidopsis RPS2-Mediated Disease Resistance

Genetics ◽

10.1093/genetics/158.1.439 ◽

2001 ◽

Vol 158 (1) ◽

pp. 439-450 ◽

Cited By ~ 4

Author(s):

Diya Banerjee ◽

Xiaochun Zhang ◽

Andrew F Bent

Keyword(s):

Disease Resistance ◽

Pseudomonas Syringae ◽

Plant Disease Resistance ◽

Effective Interaction ◽

Molecular Genetic ◽

Defense Responses ◽

Host Factors ◽

Leucine Rich Repeat ◽

Domain Swap ◽

Allele Specific

Abstract Like many other plant disease resistance genes, Arabidopsis thaliana RPS2 encodes a product with nucleotide-binding site (NBS) and leucine-rich repeat (LRR) domains. This study explored the hypothesized interaction of RPS2 with other host factors that may be required for perception of Pseudomonas syringae pathogens that express avrRpt2 and/or for the subsequent induction of plant defense responses. Crosses between Arabidopsis ecotypes Col-0 (resistant) and Po-1 (susceptible) revealed segregation of more than one gene that controls resistance to P. syringae that express avrRpt2. Many F2 and F3 progeny exhibited intermediate resistance phenotypes. In addition to RPS2, at least one additional genetic interval associated with this defense response was identified and mapped using quantitative genetic methods. Further genetic and molecular genetic complementation experiments with cloned RPS2 alleles revealed that the Po-1 allele of RPS2 can function in a Col-0 genetic background, but not in a Po-1 background. The other resistance-determining genes of Po-1 can function, however, as they successfully conferred resistance in combination with the Col-0 allele of RPS2. Domain-swap experiments revealed that in RPS2, a polymorphism at six amino acids in the LRR region is responsible for this allele-specific ability to function with other host factors.

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Expression polymorphism at theARPC4locus links the actin cytoskeleton with quantitative disease resistance toSclerotinia sclerotioruminArabidopsis thaliana

New Phytologist ◽

10.1111/nph.15580 ◽

2018 ◽

Vol 222 (1) ◽

pp. 480-496 ◽

Cited By ~ 6

Author(s):

Thomas Badet ◽

Ophélie Léger ◽

Marielle Barascud ◽

Derry Voisin ◽

Pierre Sadon ◽

...

Keyword(s):

Disease Resistance ◽

Actin Cytoskeleton ◽

Quantitative Disease Resistance ◽

Expression Polymorphism

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Avoidance of detrimental defense responses in beneficial plant–microbe interactions

Current Opinion in Biotechnology ◽

10.1016/j.copbio.2021.06.008 ◽

2021 ◽

Vol 70 ◽

pp. 266-272

Author(s):

Benjamin Gourion ◽

Pascal Ratet

Keyword(s):

Defense Responses ◽

Microbe Interactions

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Transcriptomic Analysis of Arabidopsis Seedlings in Response to an Agrobacterium-Mediated Transformation Process

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-10-17-0249-r ◽

2018 ◽

Vol 31 (4) ◽

pp. 445-459 ◽

Cited By ~ 5

Author(s):

Kaixuan Duan ◽

Christopher J. Willig ◽

Joann R. De Tar ◽

William G. Spollen ◽

Zhanyuan J. Zhang

Keyword(s):

Agrobacterium Tumefaciens ◽

Defense Response ◽

Time Course ◽

Basic Research ◽

Defense Responses ◽

Transformation Process ◽

Host Responses ◽

Nucleic Acid Metabolism ◽

Agrobacterium Strain ◽

Agrobacterium Mediated Transformation

Agrobacterium tumefaciens is a plant pathogen that causes crown gall disease. This pathogen is capable of transferring the T-DNA from its Ti plasmid to the host cell and, then, integrating it into the host genome. To date, this genetic transformation ability has been harnessed as the dominant technology to produce genetically modified plants for both basic research and crop biotechnological applications. However, little is known about the interaction between Agrobacterium tumefaciens and host plants, especially the host responses to Agrobacterium infection and its associated factors. We employed RNA-seq to follow the time course of gene expression in Arabidopsis seedlings infected with either an avirulent or a virulent Agrobacterium strain. Gene Ontology analysis indicated many biological processes were involved in the Agrobacterium-mediated transformation process, including hormone signaling, defense response, cellular biosynthesis, and nucleic acid metabolism. RNAseq and quantitative reverse transcription-polymerase chain reaction results indicated that expression of genes involved in host plant growth and development were repressed but those involved in defense response were induced by Agrobacterium tumefaciens. Further analysis of the responses of transgenic Arabidopsis lines constitutively expressing either the VirE2 or VirE3 protein suggested Vir proteins act to enhance plant defense responses in addition to their known roles facilitating T-DNA transformation.

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Perception and first defense responses against Pseudomonas syringae pv. phaseolicola in Phaseolus vulgaris L.: identification of Wall-Associated Kinase receptors

Phytopathology ◽

10.1094/phyto-10-20-0449-r ◽

2021 ◽

Author(s):

Alfonso Gonzalo De la Rubia ◽

María Luz Centeno ◽

Victor Moreno-González ◽

María De Castro ◽

Penélope García-Angulo

Keyword(s):

Phaseolus Vulgaris ◽

Pseudomonas Syringae ◽

Time Course ◽

Early Time ◽

Experimental System ◽

Antioxidant Response ◽

Defense Responses ◽

Cellular Damage ◽

Initial Increase ◽

Phaseolus Vulgaris L

Common bean (Phaseolus vulgaris L.) is attacked by several pathogens such as the biotrophic gamma-proteobacterium Pseudomonas syringae pv. phaseolicola (Pph). In order to study the Pph-bean interaction during the first stages of infection, leaf disks of a susceptible bean variety named Riñón were infected with a pathogenic Pph. Using this experimental system, six new putative Wall-Associated Kinase (WAKs) receptors, previously identified in silico, were tested. These six bean WAKs (PvWAKs) showed high protein sequence homology to the well-described Arabidopsis WAK1 (AtWAK1) receptor and, by phylogenetic analysis, clustered together with AtWAKs. The expression of PvWAK1 increased at very early stages after the Pph infection. Time course experiments were performed to evaluate the accumulation of apoplastic H2O2, Ca2+ influx, total H2O2, antioxidant enzymatic activities, lipid peroxidation, and the concentrations of abscisic acid (ABA) and salicylic acid (SA), as well as the expression of six defense-related genes – MEKK-1, MAPKK, WRKY33, RIN4, PR1 and NPR1. The results showed that overexpression of PR1 occurred 2 h after Pph infection without a concomitant increase in SA levels. Although apoplastic H2O2 increased after infection, the oxidative burst was neither intense nor rapid and an efficient antioxidant response did not occur, suggesting that the observed cellular damage was due to the initial increase in total H2O2 at early time points after infection. In conclusion, the Riñón variety can perceive the presence of Pph, but this recognition only results in a modest and slow activation of host defenses, leading to high susceptibility to Pph.

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Patterns of Gene Expression Upon Infection of Soybean Plants by Phytophthora sojae

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2004.17.10.1051 ◽

2004 ◽

Vol 17 (10) ◽

pp. 1051-1062 ◽

Cited By ~ 146

Author(s):

Pat Moy ◽

Dinah Qutob ◽

B. Patrick Chapman ◽

Ian Atkinson ◽

Mark Gijzen

Keyword(s):

Gene Expression ◽

Time Course ◽

Phytophthora Sojae ◽

Gene Microarray ◽

Pathogenesis Related ◽

Soybean Plants ◽

Related Proteins ◽

Phytoalexin Biosynthesis ◽

Host Tissues ◽

Mixed Samples

To investigate patterns of gene expression in soybean (Glycine max) and Phytophthora sojae during an infection time course, we constructed a 4,896-gene microarray of host and pathogen cDNA transcripts. Analysis of rRNA from soybean and P. sojae was used to estimate the ratio of host and pathogen RNA present in mixed samples. Large changes in this ratio occurred between 12 and 24 h after infection, reflecting the rapid growth and proliferation of the pathogen within host tissues. From the microarray analysis, soybean genes that were identified as strongly upregulated during infection included those encoding enzymes of phytoalexin biosynthesis and defense and pathogenesis-related proteins. Expression of these genes generally peaked at 24 h after infection. Selected lipoxygenases and peroxidases were among the most strongly downregulated soybean genes during the course of infection. The number of pathogen genes expressed during infection reached a maximum at 24 h. The results show that it is possible to use a single microarray to simultaneously probe gene expression in two interacting organisms. The patterns of gene expression we observed in soybean and P. sojae support the hypothesis that the pathogen transits from biotrophy to necrotrophy between 12 and 24 h after infection.

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