Irradiation influence on the phenoloxidase pathway and an anti-oxidant defense mechanism inSpodoptera litura(Lepidoptera: Noctuidae) and its implication in radio-genetic ‘F₁sterility’ and biorational pest suppression tactics

Abstract

The present study was conducted to appraise the ontogenic radio-sensitivity of a serious tropical pest, Spodoptera litura (Fabr.). The molecular responses pertaining to the phenoloxidase (PO) pathway and an anti-oxidant defense mechanism were evaluated in order to understand its implication in pest control at pre-harvest and post-harvest intervals. Irradiation exhibited an inverse relationship with age with respect to impact on developmental and transcriptional responses. Transcript abundance of PO cascade enzymes, prophenoloxidase (slppo-2), its activating enzyme (slppae-1) and free-radical scavenging enzymes, superoxide dismutase (slsod) and catalase (slcat) was evaluated upon gamma irradiation alone and the dual-stress of radiation plus microbial challenge. The slppo-2, slppae-1, slsod and slcat transcripts were significantly up-regulated in F 1 L6 larvae (6th-instar) resulting from 100 Gy sub-sterilized male adults and unirradiated female moths. The extent of upregulation was relatively higher in comparison with L6 survivors (6th-instar larvae) developed from irradiated neonates (L1) treated with 100 Gy. Upon Photorhabdus challenge, the transcripts were down-regulated in irradiated L1 suggesting increased larval susceptibility to bacterial infections. Radioresistance increased with the age of the insect, and molecular responses (transcript abundance) of insect defense mechanism were less influenced when older age (F 1 progeny) were irradiated. These findings will help to optimize the gamma dose to be employed in inherited sterility technique for (pre-harvest) pest suppression and (post-harvest) phytosanitation and quarantine, and suggest compatible integration of biorational tactics including nuclear technology.

Behavioral, Morphological, and Gene Expression Changes Induced by 60Co-γ Ray Irradiation in Bactrocera tau (Walker)

“…These results are supported by previous reports that also showed irradiation did not consistently cause differences in morphological features (Kheirallah et al, 2017 ). The reduction in the size and functionality of the female reproductive organs observed in this study would probably lead to reductions in overall fecundity and fertility (Sachdev et al, 2017 ; Stringer et al, in review). Consistent with the results of male flies in our study, Paoli et al showed that there were no differences in the ultrastructure of non-irradiated and irradiated Rhynchophorus ferrugineus Oliv sperm, except for some abnormalities in maturing spermatids (Paoli et al, 2014 ).…”

Effects of X-ray irradiation on haemocytes of Procambarus clarkii (Arthropoda: Decapoda) males

“…Interestingly, the activity of PO and pPO is not affected by ionising radiation after 20 days of the treatment, and this could, in part, explain the good survivorship of irradiated males that are able to face immunological challenges by humoral activity. In a recent study on the lepidopteran pest Spodoptera litura, it was reported that radioresistance increased in relation to the age of the insect (Sachdev et al 2017), and the use of adult crayfish could explain the unaltered PO and pPO pathways. It remains to be seen how, and how long, animals are able to offset the drastic haemocyte decline, and whether this would preclude survival in the wild.…”

Untitled

“…Enzymes and genes associated to pigmentations of insects were searched and identificated based on studies reported. There were 9 families of enzymes or genes as follow: Dopachrome converting enzyme family DEC(yellow) Futahashi et al, 2008;Ferguson et al, 2011;Futahashi et al, 2012), N-acetyltransferase(AANAT) (Hintermann et al, 1996;Tsugehara et al, 2007;Zhang et al, 2018b), Phenoloxidase(laccase2) (Futahashi et al, 2010;Yatsu et al, 2009;Futahashi et al, 2010), NBAD synthetase (ebony) (Hovemann et al, 1998;Richardt et al, 2002;Wittkopp et al, 2002;Futahashi et al, 2008;Pool et al, 2010;Takahashi et al, 2011;Ferguson et al, 2011;Zhang et al, 2018b), NBAD hydrolase (tan) (Futahashi et al, 2010;Ferguson et al, 2011;Du et al, 2018), Phenoloxidase(PO) (Zhang et al, 1997;Luna et al, 2011;Sachdev et al, 2017;Zhang et al, 2018a), Aspartate decarboxylase (ADC) (Arakane et al, 2009;Dai et al, 2015), DOPA decarboxylase (DDC\AADC) (Fang et al, 2000;Hawi et al, 2001;Chen et al, 2002;Ma et al, 2005;Yu et al, 2006;Giegling et al, 2008;Paskewitz et al, 2008;Bertoldi et al, 2009;Ferguson et al, 2011;Geomela et al, 2012), Phenylalanine hydroxylase(PAH) (Kwok et al, 1985;Johnson et al, 2003;Infanger et al, 2004;…”

“…These substances were related to some enzymes including phenylalanine hydroxylase (PAH) (Kwok et al, 1985;Zhang, 2004;Infanger et al, 2004), TH (Futahashi et al, 2008), DDC(Fang et al, 2000;Chen et al, 2002;Paskewitz et al, 2008;Giegling et al, 2008;Bertoldi et al, 2009;Ferguson et al, 2011;Hodges et al, 2012), PO (Sachdev et al, 2017;Zhang et al, 2018a), Phenoloxidase(laccase2) (Yatsu et al, 2009;Futahashi et al, 2010), NBAD synthetase (ebony) (Hovemann et al, 1998;Wittkopp et al, 2002;Takahashi et al, 2008;Takahashi et al, 2011;Ferguson et al, 2011), NBAD hydrolase (tan) (Futahashi et al, 2010;Wagner et al, 2010;Du et al, 2018), dopachrome conversion enzyme family (yellow) Futahashi et al, 2008;Ferguson et al, 2011;Futahashi et al, 2012), aspartate decarboxylase (ADC) (Arakane et al, 2009;Dai et al, 2015) and arylalkylamine-N-acetyltransferase (AANAT) (Hintermann et al, 1996;Tsugehara et al, 2007;Zhan et al, 2010;Zhang et al, 2018b). These enzymes and genes were mostly studied on the growing developments of insects (Bai et al, 2014;Sachdev et al, 2017;Zhang et al, 2018b). Meanwhile, they were studied on defense responses of other organisms (Johnson et al, 2003;Ma et al, 2005;Luna et al, 2011;Geomela et al, 2012;Hodges et al, 2012;…”

“…dorsalis (Bai et al, 2014;Chen et al, 2017;Hou et al, 2017;Sachdev et al, 2017). Pigments were recognized as being distributed in tissues of epidermis and intestines (Nijhout, 1991), and could be performed in cuticle (Barbakadze et al, 2006) while the cuticle was performed by secretion secreted in epidermal cells and contributed to the environmental adaptability of insects (Tang, 2009;Li, 2012;Fedorka et al, 2013).…”