scholarly journals Cytochrome P450 Monooxygenases CYP6AY3 and CYP6CW1 Regulate Rice Black-Streaked Dwarf Virus Replication in Laodelphax striatellus (Fallén)

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1576
Author(s):  
Jian-Hua Zhang ◽  
Ming Zhao ◽  
Yi-Jun Zhou ◽  
Qiu-Fang Xu ◽  
Yuan-Xue Yang

The small brown planthopper, Laodelphax striatellus (Fallén), is an important agricultural pest that causes significant losses by sucking and transmitting multiple plant viruses, such as rice black-streaked dwarf virus (RBSDV). Insecticides are commonly used to control planthoppers and cause the induction or overexpression of cytochrome P450 monooxygenases (P450s) from the CYP3 and CYP4 clades after insecticide application. However, little is known about the roles of insecticides and P450s in the regulation of viral replication in insects. In this study, RBSDV-infected L. striatellus were injected with imidacloprid, deltamethrin, pymetrozine, and buprofezin, respectively. The insecticide treatments caused a significant decrease in RBSDV abundance in L. striatellus. Treatment of piperonyl butoxide (PBO), an effective inhibitor of P450s, significantly increased the RBSDV abundance in L. striatellus. Fourteen P450 candidate genes in the CYP3 clade and 21 in the CYP4 clade were systematically identified in L. striatellus, and their expression patterns were analyzed under RBSDV infection, in different tissues, and at different developmental stages. Among the thirty-five P450 genes, the expression level of CYP6CW1 was the highest, while CYP6AY3 was the lowest after RBSDV infection. Knockdown of CYP6CW1 and CYP6AY3 significantly increased the virus abundance and promoted virus replication in L. striatellus. Overall, our data reveal that CYP6CW1 and CYP6AY3 play a critical role in the regulation of virus replication in L.striatellus.

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1121
Author(s):  
Marcia Beatriz Moya Fernández ◽  
Wenwen Liu ◽  
Lu Zhang ◽  
Jamal-U-Ddin Hajano ◽  
Xifeng Wang

Plant viruses transmitted by hemipteran vectors commonly cause losses to crop production. Rice stripe virus (RSV) and rice black streaked dwarf virus (RBSDV) are transmitted to rice plants by the same vector, the small brown planthopper (SBPH), Laodelphax striatellus Fallén, in a persistent propagative manner. However, rarely do the respective diseases they cause occur simultaneously in a field. Here, we determined the acquisition efficiency of RSV and RBSDV when acquired in succession or simultaneously by SBPH. When RBSDV was acquired first, RSV acquisition efficiency was significantly lower than when only acquiring RSV. However, RBSDV acquisition efficiency from insects that acquired RSV first was not significantly different between the insects only acquiring RBSDV. Immunofluorescence assays showed that the acquisition of RBSDV first might inhibit RSV entry into midgut epithelial cells, but RSV did not affect RBSDV entry. SBPHs were more likely to acquire RBSDV when they were feeding on plants coinfected with the two viruses. When RBSDV was acquired before RSV, RBSDV titer was significantly higher and RSV titer first declined, then increased compared to when only acquiring RBSDV or RSV. Only 5% of the SBPHs acquired both viruses when feeding on plants coinfected with RSV and RBSDV. These results provide a better understanding of the interaction between two persistent viruses when present in the same vector insect and explain why RSV and RBSDV occur in intermittent epidemics.


Toxicology ◽  
1994 ◽  
Vol 93 (2-3) ◽  
pp. 165-173 ◽  
Author(s):  
Morio Fukuhara ◽  
Eric Antignac ◽  
Naomi Fukusen ◽  
Kazue Kato ◽  
Masanobu Kimura

2018 ◽  
Vol 475 (23) ◽  
pp. 3875-3886 ◽  
Author(s):  
Craig S. Robb ◽  
Lukas Reisky ◽  
Uwe T. Bornscheuer ◽  
Jan-Hendrik Hehemann

Degradation of carbohydrates by bacteria represents a key step in energy metabolism that can be inhibited by methylated sugars. Removal of methyl groups, which is critical for further processing, poses a biocatalytic challenge because enzymes need to overcome a high energy barrier. Our structural and computational analysis revealed how a member of the cytochrome P450 family evolved to oxidize a carbohydrate ligand. Using structural biology, we ascertained the molecular determinants of substrate specificity and revealed a highly specialized active site complementary to the substrate chemistry. Invariance of the residues involved in substrate recognition across the subfamily suggests that they are critical for enzyme function and when mutated, the enzyme lost substrate recognition. The structure of a carbohydrate-active P450 adds mechanistic insight into monooxygenase action on a methylated monosaccharide and reveals the broad conservation of the active site machinery across the subfamily.


Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 624 ◽  
Author(s):  
Wanda Mączka ◽  
Katarzyna Wińska ◽  
Małgorzata Grabarczyk

The production of chiral sulphoxides is an important part of the chemical industry since they have been used not only as pharmaceuticals and pesticides, but also as catalysts or functional materials. The main purpose of this review is to present biotechnological methods for the oxidation of sulfides. The work consists of two parts. In the first part, examples of biosyntransformation of prochiral sulfides using whole cells of bacteria and fungi are discussed. They have more historical significance due to the low predictability of positive results in relation to the workload. In the second part, the main enzymes responsible for sulfoxidation have been characterized such as chloroperoxidase, dioxygenases, cytochrome flavin-dependent monooxygenases, and P450 monooxygenases. Particular emphasis has been placed on the huge variety of cytochrome P450 monooxygenases, and flavin-dependent monooxygenases, which allows for pure sulfoxides enantiomers effectively to be obtained. In the summary, further directions of research on the optimization of enzymatic sulfoxidation are indicated.


2019 ◽  
Vol 20 (9) ◽  
pp. 2248 ◽  
Author(s):  
Muhammad Hafeez ◽  
Sisi Liu ◽  
Saad Jan ◽  
Le Shi ◽  
G. Mandela Fernández-Grandon ◽  
...  

Plants employ an intricate and dynamic defense system that includes physiological, biochemical, and molecular mechanisms to counteract the effects of herbivorous attacks. In addition to their tolerance to phytotoxins, beet armyworm has quickly developed resistance to deltamethrin; a widely used pyrethroid insecticide in cotton fields. The lethal concentration (LC50) required to kill 50% of the population of deltamethrin to gossypol-fed Spodoptera exigua larvae was 2.34-fold higher than the control group, suggesting a reduced sensitivity as a consequence of the gossypol diet. Piperonyl butoxide (PBO) treatment was found to synergize with deltamethrin in gossypol-fed S. exigua larvae. To counteract these defensive plant secondary metabolites, beet armyworm elevates their production of detoxification enzymes, including cytochrome P450 monooxygenases (P450s). Gossypol-fed beet armyworm larvae showed higher 7-ethoxycoumarin-O-deethylase (ECOD) activities and exhibited enhanced tolerance to deltamethrin after 48 and 72 h when compared to the control. Moreover, gossypol pretreated S. exigua larvae showed faster weight gain than the control group after transferring to a deltamethrin-supplemented diet. Meanwhile, gossypol-induced P450s exhibited high divergence in the expression level of two P450 genes: CYP6AB14 and CYP9A98 in the midgut and fat bodies contributed to beet armyworm tolerance to deltamethrin. Knocking down of CYP6AB14 and CYP9A98, via double-stranded RNAs (dsRNA) in a controlled diet, rendered the larvae more sensitive to the insecticide. These data demonstrate that generalist insects can exploit secondary metabolites from host plants to enhance their defense systems against other toxic chemicals. Impairing this defense pathway by RNA interference (RNAi) holds a potential to eliminate the pest’s tolerance to insecticides and, therefore, reduce the required dosages of agrochemicals in pest control.


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