Sclerotial metamorphosis in filamentous fungi is induced by oxidative stress

Georgiou, Christos D.; Patsoukis, Nikolaos; Papapostolou, Ioannis; Zervoudakis, George

doi:10.1093/icb/icj034

Cited by 186 publications

(155 citation statements)

References 118 publications

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“…For ascomycetes, it has been reported that oxidative stress can induce differentiation (8,16). In full agreement, our analyses using antioxidants show an important decrease in conidiation in response to injury, which, together with the production of ROS by Nox1, indicate that mechanical injury generates oxidative stress, leading to conidiation in T. atroviride.…”

Section: Discussionsupporting

confidence: 90%

An injury-response mechanism conserved across kingdoms determines entry of the fungus Trichoderma atroviride into development

Hernández‐Oñate¹,

Esquivel-Naranjo²,

Mendoza‐Mendoza

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

100

139

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A conserved injury-defense mechanism is present in plants and animals, in which the production of reactive oxygen species (ROS) and lipid metabolism are essential to the response. Here, we describe that in the filamentous fungus Trichoderma atroviride, injury results in the formation of asexual reproduction structures restricted to regenerating cells. High-throughput RNA-seq analyses of the response to injury in T. atroviride suggested an oxidative response and activation of calcium-signaling pathways, as well as the participation of lipid metabolism, in this phenomenon. Gene-replacement experiments demonstrated that injury triggers NADPH oxidase (Nox)-dependent ROS production and that Nox1 and NoxR are essential for asexual development in response to damage. We further provide evidence of H 2 O 2 and oxylipin production that, as in plants and animals, may act as signal molecules in response to injury in fungi, suggesting that the three kingdoms share a conserved defense-response mechanism.conidiation | stress | transcriptome

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Section: Discussionsupporting

confidence: 90%

An injury-response mechanism conserved across kingdoms determines entry of the fungus Trichoderma atroviride into development

Hernández‐Oñate¹,

Esquivel-Naranjo²,

Mendoza‐Mendoza

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

100

139

View full text Add to dashboard Cite

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“…This finding has been supported by other studies that developed into a theory of oxidative stress as an inducer of sclerotial metamorphosis (Georgiou et al, 2006). Specifically, hydroxyl radical scavengers, vitamin C and b-carotene (both also acting as endogenous fungal antioxidants), decreased sclerotial differentiation in S. rolfsii, S. minor, S. sclerotiorum and R. solani.…”

Section: Introductionsupporting

confidence: 74%

Superoxide radical induces sclerotial differentiation in filamentous phytopathogenic fungi: a superoxide dismutase mimetics study

Papapostolou

Georgiou

2010

Microbiology

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This study shows that the superoxide radical (O 2˙" ), a direct indicator of oxidative stress, is involved in the differentiation of the phytopathogenic filamentous fungi Rhizoctonia solani, Sclerotinia sclerotiorum, Sclerotium rolfsii and Sclerotinia minor, shown by using superoxide dismutase (SOD) mimetics to decrease their sclerotial differentiation. The production rate of O 2˙" and SOD levels in these fungi, as expected, were significantly lowered by the SOD mimetics, with concomitant decrease of the indirect indicator of oxidative stress, lipid peroxidation. INTRODUCTIONSclerotial differentiation is a primitive form of differentiation exhibited by certain phytopathogenic filamentous fungi. It is expressed by four main types of sclerotia (compact bodies of aggregated hyphae), which are loose, terminal, lateral-chained and lateral-simple. These types are represented mainly, but not solely, by Rhizoctonia solani, Sclerotinia sclerotiorum, Sclerotium rolfsii and Sclerotinia minor, respectively (Chet et al., 1967(Chet et al., , 1969Chet & Henis, 1975;Le Tourneau, 1979;Willetts, 1971Willetts, , 1978Willetts, , 1997Willetts & Wong, 1980). These fungi are of great agricultural interest because they cause stem-rot diseases in a wide variety of economically important agricultural crops. Therefore, elucidating the mechanisms of sclerotium biogenesis of these fungi may lead to the development of non-toxic ways to combat plant diseases, which could be used as alternatives to the traditional toxic fungicides. Moreover, understanding sclerotial differentiation is very important because it will help to understand more complex forms of differentiation in other organisms as well as whether their mechanisms share common biochemical pathways.It has been proposed that sclerotial differentiation is related to high oxidative stress (Georgiou, 1997), based on the finding that sclerotium biogenesis in S. rolfsii was accompanied by the accumulation of high levels of lipid peroxidation products. This finding has been supported by other studies that developed into a theory of oxidative stress as an inducer of sclerotial metamorphosis (Georgiou et al., 2006). Specifically, hydroxyl radical scavengers, vitamin C and b-carotene (both also acting as endogenous fungal antioxidants), decreased sclerotial differentiation in S. rolfsii, S. minor, S. sclerotiorum and R. solani. In more recent studies, we demonstrated a strong relationship between the thiol redox state of these fungi and their sclerotial differentiation (Patsoukis & Georgiou, 2007a, b, 2008a. Specifically, in R. solani, S. rolfsii and S. minor, there was a decrease in the total amount of reduced thiols during transformation of the undifferentiated mycelium into sclerotium, which, for S. sclerotiorum was accompanied by an increase in the total oxidized components. Moreover, the antioxidant thiol redox state modulator N-acetylcysteine inhibited sclerotial differentiation in S. rolfsii, R. solani and S. sclerotiorum.Until now, our studies have associated only indirect indicators ...

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“…Oxidative stress has been suggested to be involved in the differentiation of several fungi, including Aspergillus nidulans, N. crassa, Rhizoctonia solani, Sclerotinia sclerotiorum and Sclerotinia minor, and in Sclerotium rolfsii, sclerotial biogenesis in response to mycelial injury occurs as a result of oxidative stress (Aguirre, et al, 2005;Georgiou et al, 2006;Papapostolou & Georgiou, 2010).…”

Section: Mycelial Injurymentioning

confidence: 99%

Reproduction without sex: conidiation in the filamentous fungus Trichoderma

et al. 2010

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2Lincoln Ventures Limited, PO Box 133, Lincoln University, Lincoln 7647, New Zealand Trichoderma spp. have served as models for asexual reproduction in filamentous fungi for over 50 years. Physical stimuli, such as light exposure and mechanical injury to the mycelium, trigger conidiation; however, conidiogenesis itself is a holistic response determined by the cell's metabolic state, as influenced by the environment and endogenous biological rhythms. Key environmental parameters are the carbon and nitrogen status and the C : N ratio, the ambient pH and the level of calcium ions. Recent advances in our understanding of the molecular biology of this fungus have revealed a conserved mechanism of environmental perception through the White Collar orthologues BLR-1 and BLR-2. Also implicated in the molecular regulation are the PacC pathways and the conidial regulator VELVET. Signal transduction cascades which link environmental signals to physiological outputs have also been revealed.

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Sclerotial metamorphosis in filamentous fungi is induced by oxidative stress

Cited by 186 publications

References 118 publications

An injury-response mechanism conserved across kingdoms determines entry of the fungus Trichoderma atroviride into development

An injury-response mechanism conserved across kingdoms determines entry of the fungus Trichoderma atroviride into development

Superoxide radical induces sclerotial differentiation in filamentous phytopathogenic fungi: a superoxide dismutase mimetics study

Reproduction without sex: conidiation in the filamentous fungus Trichoderma

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