Riboflavin induces Metarhizium spp. to produce conidia with elevated tolerance to UV-B, and upregulates photolyases, laccases and polyketide synthases genes
Nenhuma Miniatura disponível
Data
2018
Título da Revista
ISSN da Revista
Título de Volume
Editor
Resumo
The effect of nutritional supplementation of two Metarhizium species
with riboflavin (Rb) during production of conidia was evaluated on
(i) conidial tolerance (based on germination) to UV-B radiation and on
(ii) conidial expression following UV-B irradiation, of enzymes known to be
active in photoreactivation, viz., photolyase (Phr), laccase (Lac) and polyketide
synthase (Pks).
Methods and Results: Metarhizium acridum (ARSEF 324) and Metarhizium
robertsii (ARSEF 2575) were grown either on (i) potato dextrose agar medium
(PDA), (ii) PDA supplemented with 1% yeast extract (PDAY), (iii) PDA
supplemented with Rb (PDA+Rb), or (iv) PDAY supplemented with Rb
(PDAY+Rb). Resulting conidia were exposed to 866 7 mW m 2 of UV-B
Quaite-weighted irradiance to total doses of 3 9 or 6 24 kJ m 2
. Some conidia
also were exposed to 16 klux of white light (WL) after being irradiated, or not,
with UV-B to investigate the role of possible photoreactivation. Relative
germination of conidia produced on PDA+Rb (regardless Rb concentration) or
on PDAY and exposed to UV-B was higher compared to conidia cultivated on
PDA without Rb supplement, or to conidia suspended in Rb solution
immediately prior to UV-B exposure. The expression of MaLac3 and MaPks2
for M. acridum, as well as MrPhr2, MrLac1, MrLac2 and MrLac3 for
M. robertsii was higher when the isolates were cultivated on PDA+Rb and
exposed to UV-B followed by exposure to WL, or exposed to WL only.
Conclusions: Rb in culture medium increases the UV-B tolerance of
M. robertsii and M. acridum conidia, and which may be related to increased
expression of Phr, Lac and Pks genes in these conidia.
Significance and Impact of the Study: The enhanced UV-B tolerance of
Metarhizium spp. conidia produced on Rb-enriched media may improve the
effectiveness of these fungi in biological control programs
Descrição
Palavras-chave
Laccase, Metarhizium acridum, Metarhizium robertsii, Photolyase, Photoreactivation, Polyketide synthase, Riboflavin, Tolerance to UV-B
Citação
PEREIRA-JUNIOR, R. A. et al. Riboflavin induces Metarhizium spp. to produce conidia with elevated tolerance to UV-B, and upregulates photolyases, laccases and polyketide synthases genes. Journal of Applied Microbiology, Oxford, v. 125, n. 1, p. 159-171, 2018. DOI: 10.1111/jam.13743. Disponível em: https://academic.oup.com/jambio/article/125/1/159/6714153?login=true. Acesso em: 12 dez. 2024.