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Secondary metabolites in fungus-plant interactions.

Pusztahelyi T, Holb IJ, Pócsi I - Front Plant Sci (2015)

Bottom Line: The review introduces plant secondary metabolites usually with antifungal effect as well as the importance of signaling molecules in induced systemic resistance and systemic acquired resistance processes.It also looks through the special secondary metabolite production and host selective toxins of some significant fungal pathogens and the plant response in form of phytoalexin production.New results coming from genome and transcriptional analyses in context of selected fungal pathogens and their hosts are also discussed.

View Article: PubMed Central - PubMed

Affiliation: Central Laboratory, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen Debrecen, Hungary.

ABSTRACT
Fungi and plants are rich sources of thousands of secondary metabolites. The genetically coded possibilities for secondary metabolite production, the stimuli of the production, and the special phytotoxins basically determine the microscopic fungi-host plant interactions and the pathogenic lifestyle of fungi. The review introduces plant secondary metabolites usually with antifungal effect as well as the importance of signaling molecules in induced systemic resistance and systemic acquired resistance processes. The review also concerns the mimicking of plant effector molecules like auxins, gibberellins and abscisic acid by fungal secondary metabolites that modulate plant growth or even can subvert the plant defense responses such as programmed cell death to gain nutrients for fungal growth and colonization. It also looks through the special secondary metabolite production and host selective toxins of some significant fungal pathogens and the plant response in form of phytoalexin production. New results coming from genome and transcriptional analyses in context of selected fungal pathogens and their hosts are also discussed.

No MeSH data available.


Related in: MedlinePlus

Schematic presentation of main plant defense processes in Aspergillus flavus-maize interactions. A. flavus can attack kernels during all the six stages of their development. However, infection in non-injured kernels takes place later in the field, during the dent (R5) developmental stage just prior to physiological maturity (R6) (Marsh and Payne, 1984). As soon as 4 days after inoculation A. flavus mycelium reaches the aleurone, endosperm and germ tissue (Dolezal et al., 2013). Transcriptional analysis of the maize—A. flavus pathogen interaction revealed down-regulated (black arrow) starch biosynthesis and up-regulated genes (white arrows) of plant starch hydrolytic enzymes like β-amylase as well as downstream invertases and fructokinase. The produced hexoses flow through the up-regulated shikimate (SM) pathway, the methylerithryole (ME) pathway and toward up-regulated jasmonic acid (JA) and oxylipin biosynthesis, and feed pathogenesis related (PR) protein synthesis, e.g., peroxidases, glutathione S-transferase (GST) or chitinases that were also found up-regulated during infection. Oxylipins up-regulate aflatoxin (AF) biosynthesis and sexual reproduction in A. flavus and down-regulate fungal growth. Up-regulation of the SM pathway leads to the production of antifungal compounds flavonoids, phenylpropanoids, phytoalexins, and up-regulated lignin production in maize. Up-regulated plant hormone JA and abscisic acid (ABA) production is crucial in these defense mechanisms (Dolezal et al., 2014).
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Figure 10: Schematic presentation of main plant defense processes in Aspergillus flavus-maize interactions. A. flavus can attack kernels during all the six stages of their development. However, infection in non-injured kernels takes place later in the field, during the dent (R5) developmental stage just prior to physiological maturity (R6) (Marsh and Payne, 1984). As soon as 4 days after inoculation A. flavus mycelium reaches the aleurone, endosperm and germ tissue (Dolezal et al., 2013). Transcriptional analysis of the maize—A. flavus pathogen interaction revealed down-regulated (black arrow) starch biosynthesis and up-regulated genes (white arrows) of plant starch hydrolytic enzymes like β-amylase as well as downstream invertases and fructokinase. The produced hexoses flow through the up-regulated shikimate (SM) pathway, the methylerithryole (ME) pathway and toward up-regulated jasmonic acid (JA) and oxylipin biosynthesis, and feed pathogenesis related (PR) protein synthesis, e.g., peroxidases, glutathione S-transferase (GST) or chitinases that were also found up-regulated during infection. Oxylipins up-regulate aflatoxin (AF) biosynthesis and sexual reproduction in A. flavus and down-regulate fungal growth. Up-regulation of the SM pathway leads to the production of antifungal compounds flavonoids, phenylpropanoids, phytoalexins, and up-regulated lignin production in maize. Up-regulated plant hormone JA and abscisic acid (ABA) production is crucial in these defense mechanisms (Dolezal et al., 2014).

Mentions: Aspergillus species can be saprophytic, or symptomless endophytes or weak and opportunistic plant pathogen. A. flavus from yellow Aspergilli is a weak and opportunistic plant pathogen. It lacks host specificity (St Leger et al., 2000) as it can attack seeds of both monocots and dicots such as maize, cotton, groundnuts (peanuts) and other nuts like tree nuts such as Brazil nuts, pecans, pistachio nuts, and walnuts. A. flavus can cause ear rot on maize and preharvest contamination of these crops with SM AFs is common, but A. flavus also causes the spoilage of post-harvest grains during storage resulting in significant economic losses to farmers (Figure 10).


Secondary metabolites in fungus-plant interactions.

Pusztahelyi T, Holb IJ, Pócsi I - Front Plant Sci (2015)

Schematic presentation of main plant defense processes in Aspergillus flavus-maize interactions. A. flavus can attack kernels during all the six stages of their development. However, infection in non-injured kernels takes place later in the field, during the dent (R5) developmental stage just prior to physiological maturity (R6) (Marsh and Payne, 1984). As soon as 4 days after inoculation A. flavus mycelium reaches the aleurone, endosperm and germ tissue (Dolezal et al., 2013). Transcriptional analysis of the maize—A. flavus pathogen interaction revealed down-regulated (black arrow) starch biosynthesis and up-regulated genes (white arrows) of plant starch hydrolytic enzymes like β-amylase as well as downstream invertases and fructokinase. The produced hexoses flow through the up-regulated shikimate (SM) pathway, the methylerithryole (ME) pathway and toward up-regulated jasmonic acid (JA) and oxylipin biosynthesis, and feed pathogenesis related (PR) protein synthesis, e.g., peroxidases, glutathione S-transferase (GST) or chitinases that were also found up-regulated during infection. Oxylipins up-regulate aflatoxin (AF) biosynthesis and sexual reproduction in A. flavus and down-regulate fungal growth. Up-regulation of the SM pathway leads to the production of antifungal compounds flavonoids, phenylpropanoids, phytoalexins, and up-regulated lignin production in maize. Up-regulated plant hormone JA and abscisic acid (ABA) production is crucial in these defense mechanisms (Dolezal et al., 2014).
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Related In: Results  -  Collection

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Figure 10: Schematic presentation of main plant defense processes in Aspergillus flavus-maize interactions. A. flavus can attack kernels during all the six stages of their development. However, infection in non-injured kernels takes place later in the field, during the dent (R5) developmental stage just prior to physiological maturity (R6) (Marsh and Payne, 1984). As soon as 4 days after inoculation A. flavus mycelium reaches the aleurone, endosperm and germ tissue (Dolezal et al., 2013). Transcriptional analysis of the maize—A. flavus pathogen interaction revealed down-regulated (black arrow) starch biosynthesis and up-regulated genes (white arrows) of plant starch hydrolytic enzymes like β-amylase as well as downstream invertases and fructokinase. The produced hexoses flow through the up-regulated shikimate (SM) pathway, the methylerithryole (ME) pathway and toward up-regulated jasmonic acid (JA) and oxylipin biosynthesis, and feed pathogenesis related (PR) protein synthesis, e.g., peroxidases, glutathione S-transferase (GST) or chitinases that were also found up-regulated during infection. Oxylipins up-regulate aflatoxin (AF) biosynthesis and sexual reproduction in A. flavus and down-regulate fungal growth. Up-regulation of the SM pathway leads to the production of antifungal compounds flavonoids, phenylpropanoids, phytoalexins, and up-regulated lignin production in maize. Up-regulated plant hormone JA and abscisic acid (ABA) production is crucial in these defense mechanisms (Dolezal et al., 2014).
Mentions: Aspergillus species can be saprophytic, or symptomless endophytes or weak and opportunistic plant pathogen. A. flavus from yellow Aspergilli is a weak and opportunistic plant pathogen. It lacks host specificity (St Leger et al., 2000) as it can attack seeds of both monocots and dicots such as maize, cotton, groundnuts (peanuts) and other nuts like tree nuts such as Brazil nuts, pecans, pistachio nuts, and walnuts. A. flavus can cause ear rot on maize and preharvest contamination of these crops with SM AFs is common, but A. flavus also causes the spoilage of post-harvest grains during storage resulting in significant economic losses to farmers (Figure 10).

Bottom Line: The review introduces plant secondary metabolites usually with antifungal effect as well as the importance of signaling molecules in induced systemic resistance and systemic acquired resistance processes.It also looks through the special secondary metabolite production and host selective toxins of some significant fungal pathogens and the plant response in form of phytoalexin production.New results coming from genome and transcriptional analyses in context of selected fungal pathogens and their hosts are also discussed.

View Article: PubMed Central - PubMed

Affiliation: Central Laboratory, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen Debrecen, Hungary.

ABSTRACT
Fungi and plants are rich sources of thousands of secondary metabolites. The genetically coded possibilities for secondary metabolite production, the stimuli of the production, and the special phytotoxins basically determine the microscopic fungi-host plant interactions and the pathogenic lifestyle of fungi. The review introduces plant secondary metabolites usually with antifungal effect as well as the importance of signaling molecules in induced systemic resistance and systemic acquired resistance processes. The review also concerns the mimicking of plant effector molecules like auxins, gibberellins and abscisic acid by fungal secondary metabolites that modulate plant growth or even can subvert the plant defense responses such as programmed cell death to gain nutrients for fungal growth and colonization. It also looks through the special secondary metabolite production and host selective toxins of some significant fungal pathogens and the plant response in form of phytoalexin production. New results coming from genome and transcriptional analyses in context of selected fungal pathogens and their hosts are also discussed.

No MeSH data available.


Related in: MedlinePlus