Better cold tolerance of Bt-resistant Spodoptera exigua strain and the corresponding cold-tolerant mechanism

Su, Honghua; Zou, Jincheng; Zhou, Qiuxia; Yu, Qi; Yang, Yong; Yang, Ye

doi:10.1016/j.pestbp.2017.06.003

Cited by 4 publications

(2 citation statements)

References 38 publications

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“…For example, with the widespread planting of Bt cotton in China, S. exigua has become a major pest in such areas. 4,5 Notably, the proliferation of midgut microflora into hemolymph accelerates the death of insects due to damage caused by the Bt toxin to the insect gut tissue. 6 Insect intestinal epithelial cells are constantly in contact with microorganisms, including commensal and pathogenic bacteria.…”

Section: ■ Introductionmentioning

confidence: 99%

Involvement of Sep38β in the Insecticidal Activity of Bacillus thuringiensis against Beet Armyworm, Spodoptera exigua (Lepidoptera)

Ji,

Gao,

Zhao

et al. 2024

J. Agric. Food Chem.

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The p38 mitogen-activated protein kinases (MAPKs) are associated with insect immunity, tissue repair, and the insecticidal activity of Bacillus thuringiensis (Bt). Here, a p38 MAPK family gene (Sep38β) was identified from Spodoptera exigua. Among the developmental stages, the transcription level of Sep38β was the highest in egg, followed by that in prepupa and pupa. Sep38β expression peaked in Malpighian tubules and the hemolymph of fifth instar larvae. Knockdown of Sep38β or injection of SB203580 (a p38 MAPK inhibitor) significantly downregulated the SeDUOX expression and reactive oxygen species (ROS) level in the midgut, accounting for deterioration of the midgut to scavenge pathogens and enhancement of Bt insecticidal activity. In conclusion, all the results demonstrate that Sep38β regulates the immune-related ROS level in the insect midgut, which suppresses the insecticidal activity of Bt against S. exigua by 17−22%. Our study highlights that Sep38β is essential for insect immunity and the insecticidal activity of Bt to S. exigua and is a potential target for pest control.

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Section: ■ Introductionmentioning

confidence: 99%

Involvement of Sep38β in the Insecticidal Activity of Bacillus thuringiensis against Beet Armyworm, Spodoptera exigua (Lepidoptera)

Ji,

Gao,

Zhao

et al. 2024

J. Agric. Food Chem.

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“…B. thuringiensis shows different insecticidal activities against insect larvae without toxicity to animals ( Nair et al, 2018 ). Therefore, it has been the most widely used biopesticide for several decades, owing to its toxicity toward a broad range of insect pests, such as Helicoverpa armigera , Spodoptera exigua , and Plutella xylostella ( Lone et al, 2017 ; Su et al, 2017 ; Baragamaarachchi et al, 2019 ). Extensive planting of genetically engineered plants to produce Cry toxins has inhibited some major pests, reduced spraying of pesticides, enhanced natural enemy control of pests, and increased planting profit.…”

Section: Introductionmentioning

confidence: 99%

Bt GS57 Interaction With Gut Microbiota Accelerates Spodoptera exigua Mortality

Zhao

et al. 2022

Front. Microbiol.

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The Beet armyworm Spodoptera exigua (Lepidoptera: Noctuidae, Spodoptera) is an important global polyphagous pest. Pathogen infection could destroy the intestinal microbial homeostasis of insects, leading to the death of the host. However, the effect of the host intestinal microbial community on the insecticidal effect of Bacillus thuringiensis is rarely studied. In this study, the genome characteristics of Bt GS57 and the diversity and functions of the gut bacteria in S. exigua are investigated using crystal morphology, biological activity, and Illumina HiSeq high-throughput sequencing. The total size of the Bt GS57 genome is 6.17 Mbp with an average G + C content of 35.66%. Furthermore, the Bt GS57 genome contains six cry genes: cry1Ca, cry1Da, cry2Ab, cry9Ea, cry1Ia, and cry1Aa, and a vegetative insecticidal protein gene vip3Aa. The Bt GS57 strain can produce biconical crystals, mainly expressing 70 kDa and 130 kDa crystal proteins. The LC50 value of the Bt GS57 strain against the S. exigua larvae was 0.339 mg mL–1. Physiological and biochemical reactions showed that Bt GS57 belongs to B.t. var. thuringiensis. In addition, we found that B. thuringiensis can cause a dynamic change in the gut microbiota of S. exigua, with a significant reduction in bacterial diversity and a substantial increase in bacterial load. In turn, loss of gut microbiota significantly decreased the B. thuringiensis susceptibility of S. exigua larvae. Our findings reveal the vital contribution of the gut microbiota in B. thuringiensis-killing activity, providing new insights into the mechanisms of B. thuringiensis pathogenesis in insects.

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Cold tolerance and supercooling points of two ladybird beetles (Col.: Coccinellidae): Impact of the diet

et al. 2019

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Better cold tolerance of Bt-resistant Spodoptera exigua strain and the corresponding cold-tolerant mechanism

Cited by 4 publications

References 38 publications

Involvement of Sep38β in the Insecticidal Activity of Bacillus thuringiensis against Beet Armyworm, Spodoptera exigua (Lepidoptera)

Involvement of Sep38β in the Insecticidal Activity of Bacillus thuringiensis against Beet Armyworm, Spodoptera exigua (Lepidoptera)

Bt GS57 Interaction With Gut Microbiota Accelerates Spodoptera exigua Mortality

Cold tolerance and supercooling points of two ladybird beetles (Col.: Coccinellidae): Impact of the diet

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