Colonization of Beauveria bassiana 08F04 in root-zone soil and its biocontrol of cereal cyst nematode (Heterodera filipjevi)

Abstract

Cereal cyst nematodes cause serious yield losses of wheat in Hunaghuai winter wheat growing region in China. Beauveria bassiana 08F04 isolated from the surface of cysts is a promising biological control agent for cereal cyst nematodes. As the colonization capacity is a crucial criteria to assess biocontrol effectiveness for a microbial agent candidate, we aimed to label B. bassiana 08F04 for efficient monitoring of colonization in the soil. The binary pCAM-gfp plasmid containing sgfp and hph was integrated into B. bassiana 08F04 using the Agrobacterium tumefaciens-mediated transformation. The transformation caused a significant change in mycelial and conidial yields, and in extracellular chitinase activity in some transformants. The cultural filtrates of some transformants also decreased acetylcholinesterase activity and the survival of Heterodera filipjevi second-stage juveniles relative to the wild-type strain. One transformant (G10) had a growth rate and biocontrol efficacy similar to the wild-type strain, so it was used for a pilot study of B. bassiana colonization conducted over 13 weeks. Real-time PCR results and CFU counts revealed that the population of G10 increased quickly over the first 3 weeks, then decreased slowly over the following 4 weeks before stabilizing. In addition, the application of wild-type B. bassiana 08F04 and transformant G10 significantly reduced the number of H. filipjevi females in roots by 64.4% and 60.2%, respectively. The results of this study have practical applications for ecological, biological and functional studies of B. bassiana 08F04 and for bionematicide registration.

Cyclodepsipeptide Biosynthesis in Hypocreales Fungi and Sequence Divergence of The Non-Ribosomal Peptide Synthase Genes

“…Among these, representatives of Beauveria , Cordyceps and Isaria genera were present. All the above genera are comprised of species largely characterized as the broad host range facultative entomopathogens, important for control of insect populations in nature and with a possible use in biocontrol [ 43 , 44 , 45 ]. As such, they are frequently considered as a possible microbial insecticide against insects feeding on crops, including lepidopterans and coleopterans [ 46 , 47 , 48 ].…”

Rhizosphere 16S-ITS Metabarcoding Profiles in Banana Crops Are Affected by Nematodes, Cultivation, and Local Climatic Variations

“…Further assays are hence needed to clarify this aspect. Few data are, moreover, available in the literature for a Beauveria nematophagous activity, apart from an isolate of Beauveria bassiana obtained from cysts of Heterodera filipjevi and successfully tested as a BCA vs. the nematode juvenile stages, in controlled conditions (Zhang et al, 2020 ).…”

“…Beneficial microorganisms that contribute to plant production include species acting as generalists or, on the contrary, inhabiting specific trophic niches, ranging from endophytes to pathogens or BCA, which affect plant health and thus farm productivity (Bulgarelli et al, 2013 ; Xue et al, 2015 ; Granzow et al, 2017 ; Kaushal et al, 2020 ; Zhang et al, 2020 ; Gómez-Lama Cabanás et al, 2021 ; Ravi et al, 2021 ). Apart from plant growth promoters, soil harbors endosymbionts or BCA often specifically associated with their hosts.…”

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“…Further assays are hence needed to clarify this aspect. Few data are, moreover, available in the literature for a Beauveria nematophagous activity, apart from an isolate of Beauveria bassiana obtained from cysts of Heterodera filipjevi and successfully tested as a BCA vs. the nematode juvenile stages, in controlled conditions (Zhang et al, 2020).…”

“…Beneficial microorganisms that contribute to plant production include species acting as generalists or, on the contrary, inhabiting specific trophic niches, ranging from endophytes to pathogens or BCA, which affect plant health and thus farm productivity (Bulgarelli et al, 2013;Xue et al, 2015;Granzow et al, 2017;Kaushal et al, 2020;Zhang et al, 2020;Gómez-Lama Cabanás et al, 2021;Ravi et al, 2021). Apart from plant growth promoters, soil harbors endosymbionts or BCA often specifically associated with their hosts.…”