Comparison of non-linear temperature-dependent development rate models applied to in vitro growth of entomopathogenic fungi

Smits, Nathalie; Briere, Jean-Francois; Fargues, Jacques

doi:10.1017/s095375620300844x

Cited by 30 publications

(22 citation statements)

References 44 publications

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“…Oxidative damage can arise from Uv and thermal stress, each of which however, can also result in separate and specific form of cellular damage. The optimal growth temperature for most Beauveria and Metarhizium strains is 22-26 °C; and many strains of these fungi are restricted in growth above 32 °C and below 10 °C Hallsworth and Magan 1999;Ouedraogo et al 1997;Smits et al 2003). Temperature fluctuations can result in osmotic imbalance as well as free radical generation (oxidative stress).…”

Section: Figmentioning

confidence: 99%

Stress response signaling and virulence: insights from entomopathogenic fungi

2014

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The Ascomycete fungal insect pathogens, Beauveria and Metarhizium spp. have emerged as model systems with which to probe diverse aspects of fungal growth, stress response, and pathogenesis. Due to the availability of genomic resources and the development of robust methods for genetic manipulation, the last 5 years have witnessed a rapid increase in the molecular characterization of genes and their pathways involved in stress response and signal transduction in these fungi. These studies have been performed mainly via characterization of gene deletion/knockout mutants and have included the targeting of general proteins involved in stress response and/or virulence, e.g. catalases, superoxide dismutases, and osmolyte balance maintenance enzymes, membrane proteins and signaling pathways including GPI anchored proteins and G-protein coupled membrane receptors, MAPK pathways, e.g. (i) the pheromone/nutrient sensing, Fus3/Kss1, (ii) the cell wall integrity, Mpk1, and (iii) the high osmolarity, Hog1, the PKA/adenyl cyclase pathway, and various downstream transcription factors, e.g. Msn2, CreA and Pac1. Here, we will discuss current research that strongly suggests extensive underlying contributions of these biochemical and signaling pathways to both abiotic stress response and virulence.

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Section: Figmentioning

confidence: 99%

Stress response signaling and virulence: insights from entomopathogenic fungi

2014

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“…The Ratkowsky model has also been found to adequately describe the temperature dependence of soil respiration [5,18,35] and the total activity under anaerobic conditions (denitrification, [36]), and it has been used to model the decomposition of crop residues in soil [35,37,38]. Thus, the Ratkowsky function not only models the temperature dependency of bacterial and fungal growth in pure culture [23,24,39], but also the growth and activity of the whole microbial community. The apparent t min values determined in the present study (Table 1) were similar to those found earlier for bacteria (À6.3 to À10.8°C; [5]), fungi (À11°C; [10]) and respiration (À6.0°C; [18]) in soil.…”

Section: Discussionmentioning

confidence: 99%

Comparison of temperature effects on soil respiration and bacterial and fungal growth rates

Pietikäinen

Pettersson

Bååth

2005

FEMS Microbiology Ecology

634

386

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Temperature is an important factor regulating microbial activity and shaping the soil microbial community. Little is known, however, on how temperature affects the most important groups of the soil microorganisms, the bacteria and the fungi, in situ. We have therefore measured the instantaneous total activity (respiration rate), bacterial activity (growth rate as thymidine incorporation rate) and fungal activity (growth rate as acetate-in-ergosterol incorporation rate) in soil at different temperatures (0-45 degrees C). Two soils were compared: one was an agricultural soil low in organic matter and with high pH, and the other was a forest humus soil with high organic matter content and low pH. Fungal and bacterial growth rates had optimum temperatures around 25-30 degrees C, while at higher temperatures lower values were found. This decrease was more drastic for fungi than for bacteria, resulting in an increase in the ratio of bacterial to fungal growth rate at higher temperatures. A tendency towards the opposite effect was observed at low temperatures, indicating that fungi were more adapted to low-temperature conditions than bacteria. The temperature dependence of all three activities was well modelled by the square root (Ratkowsky) model below the optimum temperature for fungal and bacterial growth. The respiration rate increased over almost the whole temperature range, showing the highest value at around 45 degrees C. Thus, at temperatures above 30 degrees C there was an uncoupling between the instantaneous respiration rate and bacterial and fungal activity. At these high temperatures, the respiration rate closely followed the Arrhenius temperature relationship.

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“…A partir de estudo realizado por FERNANDES (2007), os fungos foram selecionados segundo a viabilidade conidial após exposição a diferentes temperaturas (5ºC e 45ºC) e à radiação UV-B, visto que são fatores ambientais limitantes na utilização desses agentes no controle biológico de artrópodes (SMITS et al, 2003). Os isolados CG 138 (Recife -PE) e CG 228 (Brasília, DF) foram obtidos de coleópteras da família Curculionidae e Chrysomelidae, respectivamente, enquanto o isolado ESALQ 986 (Piracicaba, SP) foi isolado de carrapato da família Ixodidae.…”

Section: Methodsunclassified