Molecular Cloning and Characterization of Five Glutathione S-Transferase Genes and Promoters from Micromelalopha troglodyta (Graeser) (Lepidoptera: Notodontidae) and Their Response to Tannic Acid Stress

Abstract

Plants accumulate phenolic compounds such as tannic acid to resist insect herbivores. The survival of insects exposed to toxic secondary metabolites depends on the detoxification metabolism mediated by limited groups of glutathione S-transferases (GSTs). Micromelalopha troglodyta (Graeser) (Lepidoptera: Notodontidae) is an important foliar pest of poplar trees. GSTs play an important role in xenobiotic detoxification in M. troglodyta. Five GST genes were identified in M. troglodyta and were classified into five different cytosolic GST classes, delta, omega, sigma, theta, and zeta. Real-time fluorescent quantitative polymerase chain reaction (qPCR) was used to determine the mRNA expression of the five cloned GSTs in the midguts and fat bodies of M. troglodyta. The mRNA expression of the five GSTs was significantly induced when M. troglodyta was exposed to tannic acid. To further understand the tannic acid regulatory cascade, the 5′-flanking promoter sequences of the five MtGSTs were isolated by genome walking methods, and the promoters were very active and induced by tannic acid. In summary, the induction of GST mRNA expression was due to the response of five MtGST promoters to tannic acid. Therefore, MtGST promoters play an important role in the regulation of GST transcription.

Chemical screening, insecticidal and reprotoxic activities of Tecoma stans ethanolic leaf extract against the vector mosquito Culex pipiens

“…pipiens larvae. Similar results were observed in Micromelalopha troglodyta in response to tannic acid stress (Tang et al, 2020). Previously, it was reported an induction in GST activity in Cx.…”

“…GSTs are ubiquitous multifunctional detoxification enzymes that their relationship with the resistance of insects to conventional insecticides was largely investigated (Adeyi et al, 2015). They have been recognized with their important role in xenobiotic detoxification (Tang et al, 2020). Results from the T. stans leaf extract treatment showed an induction of GST activities in Cx.…”

“…As insects could tolerate the toxicity by using several detoxification mechanisms, glutathione S‐transferase (GST) is one of the main enzymes of the phase II of detoxification (Tang et al, 2020). It is usually used in the evaluation of this toxicity due to its central role in the detoxification of both endogenous and xenobiotic compounds (Turhan et al, 2020), and play key roles in the antioxidant defence system (Abdalrahman et al, 2018).…”

Transcriptome Sequencing of the Striped Cucumber Beetle, Acalymma vittatum (F.), Reveals Numerous Sex-Specific Transcripts and Xenobiotic Detoxification Genes

“…All remaining GST subclasses considered here are cytosolic and unbound [ 51 ]. At least six cytosolic GST subclasses are known in insects—Delta, Epsilon, Sigma, Theta, Omega, and Zeta [ 41 , 42 , 52 ]. Only the Delta and Epsilon subclasses are currently known to confer insecticide resistance [ 53 ]; Delta-type GSTs are observed across all the Insecta, whereas Epsilon-type genes have only been identified in the Holometabola (which contains the Coleoptera) [ 42 ].…”

Plant secondary metabolites impact the susceptibility of caterpillars to an entomovirus

“…In particular, esterases could play a decisive role in degradation of sex pheromones of Lepidoptera (Merlin et al ., 2007;Younus et al ., 2014;Baldwin et al ., 2021). Several studies have indicated that plant secondary metabolites impact insect detoxification and their regulating genes (Dermauwet al ., 2013;Giraudo et al ., 2015;Tang et al ., 2020). Likewise, entomoviruses impact the same detoxification enzymes and their corresponding genes (Gui et al ., 2009;Shresthaet al ., 2019;.…”