Mrhox3 Effects on Conidiation and Tolerance in Metarhizium robertsii

doi:10.16409/j.cnki.2095-039x.2022.03.019

Abstract

Abstract: Metarhizium robertsii, as a model entomopathogenic fungus, has been applied in biocontrol programs of insect pests. Homeobox family genes play an important role in fungal asexual reproduction, however, its functions in entomopathogenic fungi remains unclear. Quantitative real-time PCR showed that homeobox family gene Mrhox3 is highly expressed at the conidiation and conidia stages. Gene knock-out and complementation were conducted to study the function of Mrhox3, and the results indicated that deletion of Mrhox3 did not affect the mutant’s vegetative growth and pathogenicity, but significantly weakened the conidiation ability. Further studies showed that loss of Mrhox3 significantly down-regulated the expression levels of multiple conidiation -related genes, such as the centarl regulators abaA and wetA. Loss of Mrhox3 resulted in promoted conidial germination and significantly enhanced conidial tolerance to UV and heat shock stress. This study provides a foundation for further understanding the mechanism of conidiation and conidia stress resistance in Metarhizium robertsii.

Key words: Metarhizium robertsii, Mrhox3, conidiation, abiotic stress

CLC Number:

S476.2

ZHANG Nan, WU Hao, TONG Youmin, LI Xiaojuan, HUANG Bo. Mrhox3 Effects on Conidiation and Tolerance in Metarhizium robertsii[J]. Chinese Journal of Biological Control, 2023, 39(3): 523-532.

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