Next Article in Journal
Synthesis and Anticancer Activity of New 1-Thia-4-azaspiro[4.5]decane, Their Derived Thiazolopyrimidine and 1,3,4-Thiadiazole Thioglycosides
Next Article in Special Issue
Oral Administration of the Japanese Traditional Medicine Keishibukuryogan-ka-yokuinin Decreases Reactive Oxygen Metabolites in Rat Plasma: Identification of Chemical Constituents Contributing to Antioxidant Activity
Previous Article in Journal
In Vitro DNA-Binding, Anti-Oxidant and Anticancer Activity of Indole-2-Carboxylic Acid Dinuclear Copper(II) Complexes
Previous Article in Special Issue
Research on the Relationships between Endogenous Biomarkers and Exogenous Toxic Substances of Acute Toxicity in Radix Aconiti
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Molecules
Volume 22
Issue 1
10.3390/molecules22010169
molecules-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Toxicity of Plant Secondary Metabolites Modulating Detoxification Genes Expression for Natural Red Palm Weevil Pesticide Development

by
Ahmed Mohammed AlJabr
1,†,
Abid Hussain
1,*,†,
Muhammad Rizwan-ul-Haq
1 and
Hassan Al-Ayedh
2
1
Laboratory of Bio-Control and Molecular Biology, Department of Arid Land Agriculture, College of Agricultural and Food Sciences, King Faisal University, Hofuf 31982, Al-Ahsa, Saudi Arabia
2
Life Science and Environment Research Institute, King Abdulaziz City for Science and Technology, P.O. Box 6086, Riyadh 11442, Saudi Arabia
*
Author to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Molecules 2017, 22(1), 169; https://doi.org/10.3390/molecules22010169
Submission received: 27 December 2016 / Revised: 15 January 2017 / Accepted: 17 January 2017 / Published: 20 January 2017
(This article belongs to the Collection Phytochemicals: Biosynthesis, Metabolism and Biological Activities)
Browse Figures
Versions Notes

Abstract

:
This study aimed to explore the larvicidal and growth-inhibiting activities, and underlying detoxification mechanism of red palm weevil against phenylpropanoids, an important class of plant secondary metabolites. Toxicity of α-asarone, eugenol, isoeugenol, methyl eugenol, methyl isoeugenol, coumarin, coumarin 6, coniferyl aldehyde, diniconazole, ethyl cinnamate, and rosmarinic acid was evaluated by incorporation into the artificial diet. All of the phenylpropanoids exhibited dose- and time-dependent insecticidal activity. Among all the tested phenylpropanoids, coumarin exhibited the highest toxicity by revealing the least LD50 value (0.672 g/L). In addition, the most toxic compound (coumarin) observed in the current study, deteriorated the growth resulting tremendous reduction (78.39%) in efficacy of conversion of digested food (ECD), and (ECI) efficacy of conversion of ingested food (70.04%) of tenth-instar red palm weevil larvae. The energy-deficient red palm weevil larvae through their intrinsic abilities showed enhanced response to their digestibility resulting 27.78% increase in approximate digestibility (AD) compared to control larvae. The detoxification response of Rhynchophorus ferrugineus larvae determined by the quantitative expression of cytochrome P450, esterases, and glutathione S-transferase revealed enhanced expression among moderately toxic and ineffective compounds. These genes especially cytochrome P450 and GST detoxify the target compounds by enhancing their solubility that leads rapid excretion and degradation resulting low toxicity towards red palm weevil larvae. On the other hand, the most toxic (coumarin) silenced the genes involved in the red palm weevil detoxification mechanism. Based on the toxicity, growth retarding, and masking detoxification activities, coumarin could be a useful future natural red palm weevil-controlling agent.

1. Introduction

Red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera, Curculionidae), is a severe pest of a wide genera of palms with a worldwide distribution [1,2]. Weevils destroy the vascular system of the palm trunk, which eventually lead towards the collapse and death of the infested palm [1]. The cryptic life cycle of weevils, which occurs inside the palm truck, presents serious management challenges [2]. Previously, the red palm weevil control strategy mainly depended on the use of synthetic insecticides. The intensive use of insecticides against the invaded populations of red palm weevil impart detrimental effects on non-target animals, environmental pollution, and insecticide residues in the food [3]. Recent reports on the continued low efficacy of insecticides due to the development of insecticide resistance in the most destructive pest of palm, R. ferrugineus is challenging for farmers, researchers, and policy-makers. These facts signify the importance on the development of alternative control approaches.
Different environmental friendly strategies including entomopathogenic fungi [4,5,6], nematodes [7], bacteria [8,9], development of pheromone traps [10,11,12,13], sterile insect technique [14,15,16,17], and plant based insecticides [18,19,20,21] remained the subject of previous research investigations. Among them, plant-based products especially plant secondary metabolites are the most promising alternatives to environmental deteriorating insecticides.
The metabolic pathways of plants generate tens of thousands of secondary products. These plant secondary metabolites have shown numerous benefits in different industries [22]. Currently, the untapped reservoir of plant secondary metabolites are of particular interest in insecticide development [23]. These natural compounds gaining importance in pest management due to various deleterious effects including anti-feedant, toxic, repellent, fumigant, attractant, molting disruption, respiratory inhibition, pheromone-based behavioral adaptations, oviposition deterrence, and fecundity reduction against target pest populations [23,24,25,26,27]. In the past, this broad-spectrum approach was ignored in red palm weevil control. Little research data of preliminary stages are available on the use of plant-based raw products including essential oils [18,28], plant extracts [20,29,30], plant metabolites, such as rotenone and limonine [31], against red palm weevils.
Phenylpropanoid plant secondary metabolites are synthesized by phenylalanine within the plants. These compounds (phenylpropanoids) have been isolated from throughout the plant kingdom. The insecticidal potential of different phenylpropanoids have been tested against different pest species in a number of investigations [32,33,34,35]. A literature survey has shown that there is no report on the use of phenylpropanoids against red palm weevils, thus, we decided for the first time, to investigate the insecticidal potential of phenylpropanoids. Our study aimed to (1) screen the toxicity of selected phenylpropanoid plant secondary metabolites including α-asarone, eugenol, isoeugenol, methyl eugenol, methyl isoeugenol, coumarin, coumarin 6, coniferyl aldehyde, diniconazole, ethyl cinnamate, and rosmarinic acid against red palm weevils; (2) determine the influence of phenylpropanoids on the feeding performance of R. ferrugineus larvae; and (3) explore the host detoxification mechanism against the toxicity of phenylpropanoids to pave the way for the isolation and development of eco-friendly compounds against red palm weevils.

2. Results

2.1. Dose Mortality Response

Toxicity of selected phenylpropanoids toward red palm weevil larvae varied significantly. However, only coumarin caused 100% mortality with the least LD50 value after three days (0.672 g/L); and found to be the most toxic phenylpropanoid in the current study (Figure 1; Table 1). Comparatively, coumarin at all tested doses (F = 893.67; df = 4, 64; p < 0.0001), time intervals (F = 189.63; df = 3, 64; p < 0.0001), and their interaction (F = 95.28; df = 12, 64; p < 0.0001) imparted significantly higher mortality (Figure 1). In our toxicity analysis, rosmarinic acid, methyl isoeugenol, and methyl eugenol showed very little promise in red pam weevil control because they failed to impart 50% mortality even at a dose of 25 g/L during the course of whole experimentation (Table 1). On the other hand, seven phenylpropanoids, including ethyl cinnamate, diniconazole, isoeugenol, coumarin 6, α-asarone, eugenol, and coniferyl aldehyde imparted > 50% mortality and their LD50 values calculated after 12 days ranged between 6 and 28 g/L (Table 1). However, the interaction of dose mortality response at different time intervals for ethyl cinnamate (F = 10.30; df = 12, 64; p < 0.0001), diniconazole (F = 6.42; df = 12, 64; p < 0.0001), isoeugenol (F = 9.65; df = 12, 64; p < 0.0001), coumarin 6 (F = 13.37; df = 12, 64; p < 0.0001), α-asarone (F = 4.64; df = 12, 64; p < 0.0001), eugenol (F = 3.22; df = 12, 64; p < 0.0001), and coniferyl aldehyde (F = 1.14; df = 12, 64; p < 0.0001) were significantly different (Figure 1). Overall, these seven phenylpropanoids due to high LD50 values and slow mode of action found to be less toxic to red palm weevil larvae.

2.2. Growth Inhibition Activities of Red Palm Weevil Larvae

The incorporation of each tested phenylpropanoid at a dose of 0.672 g/L into the artificial diet to calculate nutritional indices including ECI, ECD, and AD after 72 h of feeding have shown tremendous variations in their response. Red palm weevil larvae fed on diets incorporated with coumarin showed the highest reduction in ECD (78.39%), and remained significantly different to all other diets incorporated with other phenylpropanoids (F = 146; df = 11, 48; p < 0.0001). However, the lowest reduction (<15%) was observed from the diets incorporated with methyl eugenol, methyl isoeugenol, rosmarinic acid, coniferyl aldehyde, eugenol, and α-asarone (Table 2).
The most toxic compound (coumarin) screened in the current study also tremendously reduced (70.04%) the ECI of R. ferrugineus larvae. The remaining treatments failed to impart tremendous reduction, resulting in <12% reduction compared to the control treatment diet. However, significant differences in the ECI index among the tested compounds were observed (F = 170; df = 11, 48; p < 0.0001). Furthermore, the ECI index of methyl eugenol and methyl isoeugenol remained significantly at the same level compared to the control treatment diets (Table 2). Overall, inhibition in growth indices (ECI and ECD) directly proportional to the toxicity of phenylpropanoids. The highly toxic compound, coumarin, screened in the current study, imparted the highest inhibition in the ECI and ECD indexes. On the other hand, the least toxic compounds failed to inhibit growth indices of R. ferrugineus larvae. On the contrary, an inversely proportional relationship was observed between AD and toxicity of the isolates compared to the ECI and ECD indices (Table 2). The most toxic compound, coumarin, significantly enhanced (27.78%) the AD of R. ferrugineus larvae compared to the control treatment larvae. The artificial diets incorporated with all other tested phenylpropanoids failed to tremendously enhance AD. and resulted in <11% compared to control treatment larvae. However, AD significantly increased upon exposure to different treatments (F = 208; df = 11, 48; p < 0.0001).

2.3. Quantitative Reverse Transcription Polymerase Chain Reaction Analyses of Red Palm Weevil Detoxification Genes

Toxicity of tested plant phenylpropanoids induced different levels of detoxification (cytochrome P450, glutathione S-transferase, and esterase) genes (Figure 2). The expression of detoxification genes (F = 2269.48; df = 2, 132; p < 0.0001), upon feeding on different treatments (F = 500.51; df = 10, 132; p < 0.0001) and their interaction (F = 136.94; df = 20, 132; p < 0.0001), showed significant differences. Larvae fed on diet incorporated with methyl eugenol, methyl isoeugenol, and rosmarinic acid tremendously enhanced the expression of tested detoxification genes especially GST and cytochrome P450 (Figure 2). Among all the detoxification genes, GST showed the highest expression. All of the treatments, except coumarin, greatly induced the expression of GST and cytochrome P450 (Figure 2). However, esterase failed to induce expression and remained significantly at lower level compared to other tested detoxification genes.

3. Discussion

Red palm weevil control is facing a threat because of the development of insecticide resistance in Rhynchophorus ferruginous against conventional synthetic insecticides, warranting the development of newer plant-based eco-friendly insecticides [3]. Our screening program for discovering potent compounds was designed by evaluating toxicity, feeding performance and host detoxification against selected phenylpropanoids. We have reported for the first time the toxicity and growth retarding activities of coumarin that disturbed the genes that regulate detoxification mechanism.
Dietary laboratory experimentation of selected phenylpropanoids (Figure 3) against red palm weevil larvae exhibited various biological effects from low to high degrees. Among all the tested compounds, artificial diet incorporated with coumarin, showed acute toxicity, imparting the least LD50 (0.672 g/L) against red palm weevil larvae. The efficacy of coumarin is equivalent to the efficacy observed by Moreira et al. [34], who examined the effect of coumarin on coleopterons infesting stored products. They found coumarin as the best treatment against Oryzaephilus surinamensis (L), and Rhyzopertha dominica (F) at all the studied time intervals. The LD50 results reported by Moreira et al. [34], coincides with our findings against red palm weevil larvae. The LD50 of R. dominica reported by Moriera after 6 h was 39.71 mg/g (39,710 ppm), while after 12 h it was 20.82 mg/g (20,820 ppm) that was 47.57% decrease in LD50 value compared to 6 h LD50 value. Furthermore, LD50 value after 24 h was 11.82 mg/g (11,820 ppm) that was 70.23% decrease in LD50 value compared to 6 h LD50 value. The difference in LD50 values between our results against red palm weevil with R. dominica and O. surinamensis mainly because of the time to calculate LD50 values as reflected in the Table 1. However, the toxicity calculated through LD50 values of other phenylpropanoids ranged from moderate (ethyl cinnamate, diniconazole, isoeugenol, coumarin 6, α-asarone, eugenol and coniferyl aldehyde) to ineffective (rosmarinic acid, methyl isoeugenol, and methyl eugenol) against red palm weevil larvae. Toxicity results of rosmarinic acid, methyl isoeugenol, and methyl eugenol at the highest concentration (25 g/L) during the course of whole experimentation without attaining 50% mortality showed that these compounds have little promise to be used as bio-pesticide against R. ferruginous larvae.
Coumarin imparted significant reductions in the feeding performance of R. ferrugineus larvae, when it incorporated into the diet at a dose of 0.672 g/L. Tenth-instar R. ferruginous larvae fed on a coumarin-containing diet showed the least efficacy of conversion of ingested (ECI), and digested (ECD) diet, which meant that less food was available for growth because most of the energy was metabolized for host defense. Similar nutritional indices patterns of ECD and ECI in red palm weevil larvae were reported, when larvae were dipped in conidial suspensions of entomopathogenic fungi [4,5], or larvae fed on diets incorporated with synthetic pesticides [3]. Such tremendous reductions in ECI (70.04%), and ECD (78.39%) by coumarin compared to control larvae observed in the current study revealed that most of the energy from ingested food is being used to perform physiological activities to combat the toxin (coumarin), which means that less food is being utilized for larval growth and development. In contrast, coumarin 6, α-asarone, eugenol and coniferyl aldehyde, rosmarinic acid, methyl isoeugenol, and methyl eugenol failed to impart significant reductions in ECI and resulting less than 10% reduction in ECI compared to control suggesting low toxicity potential of these tested compounds against tenth-instar red palm weevil larvae. In addition, such minor reductions in ECD compared to control were observed when larvae were fed on diet incorporated with rosmarinic acid (10.36%), methyl isoeugenol (5.26%), and methyl eugenol (2.42%). Previous research reported the contact and fumigation action of methyleugenol, (E)-methyl isoeugenol, and α-asarone against Liposcelis bostrychophila Badonnel [33]. Their findings reported much lower LD50 (125.73 μg/cm2) of α-asarone by contact toxicity bioassays compared to our LD50 (17.670 g/L) results suggesting its little potential in controlling red palm weevil larvae.
Bioactivity of the most potent compound (coumarin) evaluated in the current study greatly enhanced (27.78%) the approximate digestibility (AD) compared to the control treatment R. ferrugineus tenth-instar larvae. The enhanced response of AD values among coumarin-fed R. ferrugineus larvae unveil the fact of the use of some extra energy for host defense. In order to fulfill this energy shortfall, treated larvae through their intrinsic abilities enhanced their approximate digestibility of the limited foodstuff. Previous laboratory investigations also reported similar enhanced AD response among R. ferrugineus larvae to pesticides [3]; and fungal conidia [4,5]; Ocinara varians larvae to fungal suspensions [36].
The physiological responses of R. ferrugineus larvae promote the expression of genes involved in the detoxification of toxic phenylpropanoids by enhancing metabolic mechanisms of target pest. Hussain et al. [3] reported the enhanced activity of GST among resistant populations of red palm weevil fed on artificial diet incorporated with cypermethrin. Among all the detoxification genes evaluated in the current study, GST gene was highly expressed indicating that GST rapidly detoxify the compounds especially α-asarone, eugenol, coniferyl aldehyde, rosmarinic acid, methyl isoeugenol, and methyl eugenol resulting more than 10% GST expression. Similar enhanced expression was also reported in the current investigations in the case of cytochrome P450. However, their expression remained significantly lower compared to GST expression (Figure 2). In the past, the expression of GST, cytochrome P450, and esterase against toxicants in other pest species is well documented [37,38,39]. The high expression of GST and cytochrome P450 directly related with the detoxification of host against the tested compounds. These genes detoxify the target compounds by enhancing their solubility that leads rapid excretion and degradation [40]. The lethality of phenylpropanoids are greatly reduced by the enhanced expression of detoxification genes especially GST and cytochrome P450. The most toxic compound (coumarin) target GST and cytochrome P450 genes resulting silencing/masking their expression that ultimately lead to the lowest LD50 value (0.672 g/L). In contrast, esterase studied in the current investigations did not greatly stimulate the tested compounds and their expression remained very little. The low expression does not necessarily mean that these genes are not involved in host defense against toxicant. Furthermore, it cannot be ruled out that low expression genes might involve in defense to other toxicants not tested.

4. Materials and Methods

4.1. Insects

The red palm weevils (R. ferruginous) were obtained from the laboratory cultures previously collected from the date palm infested fields in October-December 2014. Adults were shifted to pineapples in cages (57.5 cm × 29 cm × 58 cm) for mating and oviposition at 30 ± 1 °C, 75% ± 5% relative humidity (RH), with a 16-h light photoperiod. Neonates were fed on pineapples. However, second instar R. ferrugineus larvae were shifted individually to an artificial diet in 400 mL perforated plastic cups at 30 ± 1 °C, 75% ± 5% relative humidity (RH) with a 16-h light photoperiod [4].

4.2. Phenylpropanoid Plant Secondary Metabolites

Eleven phenylpropanoids, including α-asarone, eugenol, isoeugenol, methyl eugenol, methyl isoeugenol, coumarin, coumarin 6, coniferyl aldehyde, diniconazole, ethyl cinnamate, and rosmarinic acid, based on their toxicity to other pest species as shown in Figure 3 were purchased from Sigma Aldrich, London, UK.

4.3. Toxicity Bioassays

In the laboratory, range-finding studies were performed to decide the appropriate doses of phenylpropanoids against red palm weevil larvae. The pure compounds were dissolved in acetone and diluted in distilled water. Five doses of each tested compound were incorporated into the artificial diet to determine the toxicity of red palm weevil larvae. Control treatment diet was prepared using similar volume of acetone and distilled water. Twenty-five tenth-instar red palm weevil larvae were used for each treatment. Each larva was singly-fed on a treated artificial diet in aerated plastic bowls at 30 ± 1 °C, 75% ± 5% relative humidity (RH) with a 16-h light photoperiod. Five replicates from different red palm weevil generations for each treatment and control were prepared to compile toxicity bioassays. Dose mortality data were recorded daily. Toxicity bioassays were repeated over time on different red palm weevil generations. The observed mortality data of red palm weevil larvae were corrected for control mortality by commonly used Abbott’s formula [41]. All replicate results were subjected to Probit analysis to determine LD50 values using POLO software (LeOra Software LLC, Berkeley, CA, USA) [42]. Angularly transformed corrected cumulative mortality data at different time intervals were analyzed by repeated measures ANOVA with Fisher’s LSD test [43].

4.4. Nutritiopnal Indices of Red Palm Weevils

Feeding performance was calculated with tenth-instar red palm weevil larvae as these larger larvae and their frass could easily be handled and accurately weighed. Diets were prepared separately using LD50 value for each compound based on toxicological laboratory bioassays. In this experiment, twenty-five red palm weevil tenth-instar larvae per replicate were separately provided with artificial diet incorporated with the phenylpropanoids in aerated plastic bowls at 30 ± 1 °C, 75% ± 5% relative humidity (RH) with a 16-h light photoperiod. Among all of the treatments, coumarin was found to be the most potent compound. For nutritional indices, artificial diets were supplemented with either α-asarone, eugenol, isoeugenol, methyl eugenol, methyl isoeugenol, coumarin, coumarin 6, coniferyl aldehyde, diniconazole, ethyl cinnamate, and rosmarinic acid at the dose of 0.672 g/L based on the LD50 value of the most potent treatment (coumarin) as determined in laboratory toxicology bioassays against same instar (tenth) red palm weevil larvae. Five replicates from different red palm weevil generations for each treatment and control were prepared for feeding performance bioassays. After three days of experimentation, weight gained by each larva was accurately measured by analytical weight balance. In addition, food consumed and frass produced by each larva was determined by analytical weight balance. These measurements were used to determine nutritional indices of tenth-instar R. ferrugineus larvae. Nutritional indices including, efficacy of conversion of digested food (ECD = weight gained by the larva/(food ingested by the larva-dry weight of frass excreted by larvae)), efficacy of conversion of ingested food (ECI = 100 × dry weight gained by the larva/dry weight of food consumed by larva), and approximate digestibility (AD = (food ingested − frass weight)/food ingested × 100) were calculated as described in previous experimentation [4,5]. Significant differences between growth nutritional indices generated from larvae fed on diets incorporated with different phenylpropanoids were determined using one-way ANOVA and Fisher’s LSD test using SAS [44].

4.5. Host Detoxification Mechanism

The expression profiles of detoxification genes were validated by real-time quantitative PCR from the midgut portion of the alimentary canal of tenth-instar red palm weevil larvae, as these larger larvae have enough midgut to extract total RNA from single larva. In this exploration, red palm weevil (tenth-instar) larvae were fed in separate aerated plastic bowls on each treatment diet prepared by incorporating each tested phenylpropanoid compound separately at a dose of 0.672 g/L based on the LD50 value of the most potent treatment (coumarin) as determined in laboratory toxicology bioassays against same instar (tenth) red palm weevil larvae. The experimental units were kept at 30 ± 1 °C, 75% ± 5% relative humidity (RH) with a 16-h light photoperiod. Seventy-two hours post-feeding, tenth-instar larvae were dissected in saline for subsequent grinding of mid-gut portion in liquid nitrogen. A commercially available RNeasy® Universal Mini Kit (Qiagen, Hilden, Germany) was used to extract total RNA from five larvae and each regarded as one replicate. The extracted total RNA of each treatment was reverse-transcribed using PrimeScript First Strand cDNA Kit (TaKaRa Clontech, Paris, France). This template (first strand cDNA) of each treatment along with specific primers (Table 3) were used to quantify target gene expression in CFX96 TouchTM (Bio-Rad, London, UK) using SYBR® Premix Ex Taq™ II kit (TaKaRa Clontech, Paris, France). The numerical values obtained from each experimental unit were compared with those of the control by relative fold expression obtained by transforming the obtained results into absolute values using 2−ΔΔCt [45]. In case of control, the relative expression of each gene was set to 1. beta-Actin (GenBank accession #KM438516) due to its low expression variations was chosen as housekeeping gene. The mid-gut samples extracted from red palm weevil larvae fed on different diets were analyzed by one-way ANOVA and the significant differences between means were determined by applying Fisher’s LSD test [44].

5. Conclusions

In conclusion, feeding red palm weevil larvae on coumarin tremendously reduced their survival, adversely affected their growth and development, and inhibited the expression of detoxification genes, including GST and cytochrome P450. These characteristics suggest coumarin as a biologically-active valuable source for future eco-friendly commercial development of coumarin against the infestations of red palm weevils.

Acknowledgments

The study was supported by the Deanship of King Faisal University, Kingdom of Saudi Arabia (Project No. 160078).

Author Contributions

Ahmed Mohammed AlJabr and Abid Hussain conceived and designed the experiments; Abid Hussain and Muhammad Rizwan-ul-Haq performed the experiments; Muhammad Rizwan-ul-Haq, Hassan Al-Ayedh and Ahmed Mohammed AlJabr analyzed the data; Hassan Al-Ayedh and Ahmed Mohammed AlJabr contributed reagents/materials/analysis tools; Abid Hussain, Muhammad Rizwan-ul-Haq, Ahmed Mohammed AlJabr and Hassan Al-Ayedh wrote the paper.

Conflicts of Interest

The authors declare no conflict of interest. The founding sponsor had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.

References

  1. Hussain, A.; Rizwan-ul-haq, M.; Al-jabr, A.M. Red palm weevil: Understanding the fungal disease mechanism and host defense. In Microbial Pathogens and Strategies for Combating Them: Science, Technology and Education; Formatex Research Center: Badajoz, Spain, 2013; pp. 1278–1286. [Google Scholar]
  2. Hussain, A.; Rizwan-ul-Haq, M.; Al-Jabr, A.M.; Al-Ayied, H.Y. Managing invasive populations of red palm weevil: A worldwide perspective. J. Food Agric. Environ. 2013, 11, 456–463. [Google Scholar]
  3. Al-Ayedh, H.; Hussain, A.; Rizwan-ul-Haq, M.; Al-Jabr, A.M. Status of insecticide resistance in field-collected populations of Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae). Int. J. Agric. Biol. 2016, 18, 103–110. [Google Scholar] [CrossRef]
  4. Hussain, A.; Rizwan-ul-Haq, M.; Al-Ayedh, H.; AlJabr, A. Susceptibility and immune defence mechanisms of Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) against entomopathogenic fungal infections. Int. J. Mol. Sci. 2016, 17, 1518. [Google Scholar] [CrossRef] [PubMed]
  5. Hussain, A.; Rizwan-ul-Haq, M.; Al-Ayedh, H.; Ahmed, S.; Al-Jabr, A.M. Effect of Beauveria bassiana infection on the feeding performance and antioxidant defence of red palm weevil, Rhynchophorus ferrugineus. BioControl 2015, 60, 849–859. [Google Scholar] [CrossRef]
  6. Dembilio, Ó.; Quesada-Moraga, E.; Santiago-Álvarez, C.; Jacas, J.A. Potential of an indigenous strain of the entomopathogenic fungus Beauveria bassiana as a biological control agent against the red palm weevil, Rhynchophorus ferrugineus. J. Invertebr. Pathol. 2010, 104, 214–221. [Google Scholar] [CrossRef] [PubMed]
  7. Dembilio, Ó.; Llácer, E.; de Martínez Altube, M.; Jacas, J.A. Field efficacy of Imidacloprid and Steinernema carpocapsae in a chitosan formulation against the red palm weevil Rhynchophorus ferrugineus (Coleoptera: Curculionidae) in Phoenix canariensis. Pest Manag. Sci. 2010, 66, 365–370. [Google Scholar] [CrossRef] [PubMed]
  8. Pu, Y.; Hou, Y. Isolation and identification of bacterial strains with insecticidal activities from Rhynchophorus ferrugineus Oliver (Coleoptera: Curculionidae). J. Appl. Entomol. 2016, 140, 617–626. [Google Scholar] [CrossRef]
  9. Francesca, N.; Alfonzo, A.; Verde, G.L.; Settanni, L.; Lucido, P. Biological activity of Bacillus spp. evaluated on eggs and larvae of red palm weevil Rhynchophorus ferrugineus. Ann. Microbiol. 2015, 65, 477–485. [Google Scholar] [CrossRef] [Green Version]
  10. Guarino, S.; Colazza, S.; Peri, E.; Bue, P.Lo.; Germanà, M.P.; Kuznetsova, T.; Gindin, G.; Soroker, V. Behaviour-modifying compounds for management of the red palm weevil (Rhynchophorus ferrugineus Oliver). Pest Manag. Sci. 2015, 71, 1605–1610. [Google Scholar] [CrossRef] [PubMed]
  11. Guarino, S.; Peri, E.; Lo Bue, P.; Germanà, M.P.; Colazza, S.; Anshelevich, L.; Ravid, U.; Soroker, V. Assessment of synthetic chemicals for disruption of Rhynchophorus ferrugineus response to attractant-baited traps in an urban environment. Phytoparasitica 2013, 41, 79–88. [Google Scholar] [CrossRef]
  12. Hoddle, M.; Al-Abbad, A.H.; El-Shafie, H.; Faleiro, J.; Sallam, A.; Hoddle, C. Assessing the impact of areawide pheromone trapping, pesticide applications, and eradication of infested date palms for Rhynchophorus ferrugineus (Coleoptera: Curculionidae) management in Al Ghowaybah, Saudi Arabia. Crop Prot. 2013, 53, 152–160. [Google Scholar] [CrossRef]
  13. Abbas, M.S.T.; Hanounik, S.B.; Shahdad, A.S.; AI-Bagham, S.A. Aggregation pheromone traps, a major component of IPM strategy for the red palm weevil, Rhynchophorus ferrugineus in date palms (Coleoptera: Curculionidae). J. Pest Sci. 2006, 79, 69–73. [Google Scholar] [CrossRef]
  14. Al-Ayedh, H.Y.; Rasool, K.G. Determination of the optimum sterilizing radiation dose for control of the red date palm weevil Rhynchophorus ferrugineus Oliv. (Coleoptera: Curculionidae). Crop Prot. 2010, 29, 1377–1380. [Google Scholar] [CrossRef]
  15. Paoli, F.; Dallai, R.; Cristofaro, M.; Arnone, S.; Francardi, V.; Roversi, P.F. Morphology of the male reproductive system, sperm ultrastructure and γ-irradiation of the red palm weevil Rhynchophorus ferrugineus Oliv. (Coleoptera: Dryophthoridae). Tissue Cell 2014, 46, 274–285. [Google Scholar] [CrossRef] [PubMed]
  16. Mazza, G.; Inghilesi, A.F.; Stasolla, G.; Cini, A.; Cervo, R.; Benvenuti, C.; Francardi, V.; Cristofaro, M.; Arnone, S.; Roversi, P.F. Sterile Rhynchophorus ferrugineus males efficiently impair reproduction while maintaining their sexual competitiveness in a social context. J. Pest Sci. 2015, 89, 459–468. [Google Scholar] [CrossRef]
  17. El Naggar, S.E.M.; Mohamed, H.F.; Mahmoud, E.A. Studies on the morphology and histology of the ovary of red palm weevil female irradiated with gamma rays. J. Asia. Pac. Entomol. 2010, 13, 9–16. [Google Scholar] [CrossRef]
  18. Shukla, P.; Vidyasagar, P.S.P.V.; Aldosari, S.A.; Abdel-Azim, M. Antifeedant activity of three essential oils against the red palm weevil, Rhynchophorus ferrugineus. Bull. Insectol. 2012, 65, 71–76. [Google Scholar]
  19. Cangelosi, B.; Clematis, F.; Monroy, F.; Roversi, P.F.; Troiano, R.; Curir, P.; Lanzotti, V. Filiferol, a chalconoid analogue from Washingtonia filifera possibly involved in the defence against the red palm weevil Rhynchophorus ferrugineus Olivier. Phytochemistry 2015, 115, 216–221. [Google Scholar] [CrossRef] [PubMed]
  20. Salama, H.; Ismail, I. Potential of certain natural extracts for the control of the red palm weevil, Rhynchophorus ferrugineus (Oliver). Arch. Phytopathol. Plant Prot. 2007, 40, 233–236. [Google Scholar] [CrossRef]
  21. Abdullah, M.A. Toxicological and histopathological studies of Boxus chinensis oil and precocene II on larvae of the red palm weevil Rynchophorus ferrugineus (Oliver) (Coleoptera: Curculionidae). Egypt. Acad. J. Biol. Sci. 2009, 2, 45–54. [Google Scholar]
  22. Nascimento, N.C.; Fett-Neto, A.G. Plant secondary metabolism and challenges in modifying its operation: An overview. In Plant Secondary Metabolism Engineering Methods and Applications; Fett-Neto, A.G., Ed.; Humana Press: New York, NY, USA, 2010; pp. 1–13. [Google Scholar]
  23. Isman, M.B. Botanical insecticides, deterrents, and repellents in modern agriculture and an increasingly regulated world. Annu. Rev. Entomol. 2006, 51, 45–66. [Google Scholar] [CrossRef] [PubMed]
  24. Tan, K.H.; Nishida, R. Methyl eugenol: Its occurrence, distribution, and role in nature, especially in relation to insect behavior and pollination. J. Insect Sci. 2012, 12. [Google Scholar] [CrossRef] [PubMed]
  25. Scott, I.; Jensen, H.; Scott, J.; Isman, M.; Arnason, J.; Philogène, B. Botanical insecticides for controlling agricultural pests: Piperamides and the Colorado Potato Beetle Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae). Arch. Insect Biochem. Physiol. 2003, 54, 212–225. [Google Scholar] [CrossRef] [PubMed]
  26. Zhao, B.; Grant, G.; Langevin, D.; MacDonald, L. Deterring and inhibiting effects of quinolizidine alkaloids on spruce budworm (Lepidoptera: Tortricidae) oviposition. Environ. Entomol. 1998, 27, 984–992. [Google Scholar] [CrossRef]
  27. Koul, O. Phytochemicals and insect control: An antifeedant approach. CRC Crit. Rev. Plant Sci. 2008, 27, 1–24. [Google Scholar] [CrossRef]
  28. Nassar, M.; Abdulah, A. Assessment of Boxus chinensis oil and precocene II for the control of the red palm weevil, Rhychophorus ferrugineus (Oliv.) (Coleoptera-Curculionidae) and the palm beetle, Pseudophilus testaceous. J. Entomol. 2005, 2, 1–8. [Google Scholar]
  29. El-Bokl, M.M.; Baker, R.F.; El-Gammal, H.L.; Mahmoud, M.Z. Biological and histopathological effects of some insecticidal agents against red palm weevil Rhynchophorus ferrugineus. Egypt. Acad. J. Biol. Sci. Histol. Histochem. 2010, 1, 7–22. [Google Scholar]
  30. Nassar, M.; Abdullah, M. Evaluation of azadirachtin for control of the red palm weevil Rhynchophorus ferrugineus (Olivier) (Coleoptera, Curculionidae). J. Egypt. Ger. Soc. Zool. 2001, 36, 163–173. [Google Scholar]
  31. Abdullah, M.A.R. Identification of the biological active compounds of two natural extracts for the control of the red palm weevil, Rhynchophorus ferrugineus (Oliver) (Coleoptera: Curculionidae). Egypt Acad. J. Biol. Sci. 2009, 2, 35–44. [Google Scholar]
  32. Ahn, Y.J.; Kim, N.J.; Byun, S.G.; Cho, J.E.; Chung, K. Larvicidal activity of Kaempferia galanga rhizome phenylpropanoids towards three mosquito species. Pest Manag. Sci. 2008, 64, 857–862. [Google Scholar] [CrossRef] [PubMed]
  33. Liu, X.; Zhou, L.; Liu, Z.; Du, S. Identification of insecticidal constituents of the essential oil of Acorus calamus rhizomes against Liposcelis bostrychophila Badonnel. Molecules 2013, 18, 5684–5696. [Google Scholar] [CrossRef] [PubMed]
  34. Moreira, M.D.; Picanço, M.C.; de Barbosa, L.C.A.; Guedes, R.N.C.; de Campos, M.R.; Silva, G.A.; Martins, J.C. Plant compounds insecticide activity against coleoptera pests of stored products. Pesqui. Agropecuária Bras. 2007, 42, 909–915. [Google Scholar] [CrossRef]
  35. Sharma, R.; Negi, D.S.; Shiu, W.K.P.; Gibbons, S. Characterization of an insecticidal coumarin from Boenninghausenia albiflora. Phyther. Res. 2006, 20, 607–609. [Google Scholar] [CrossRef] [PubMed]
  36. Hussain, A.; Tian, M.Y.; He, Y.R.; Ahmed, S. Entomopathogenic fungi disturbed the larval growth and feeding performance of Ocinara varians (Lepidoptera: Bombycidae) larvae. Insect Sci. 2009, 16, 511–517. [Google Scholar] [CrossRef]
  37. Rashid, M.; Khan, R.A.; Zhang, Y.L. Over-expression of cytochrome P450s in Helicoverpa armigera in response to bioinsecticide, cantharidin. Int. J. Agric. Biol. 2013, 15, 993–997. [Google Scholar]
  38. Halon, E.; Eakteiman, G.; Moshitzky, P.; Elbaz, M.; Alon, M.; Pavlidi, N.; Vontas, J.; Morin, S. Only a minority of broad-range detoxification genes respond to a variety of phytotoxins in generalist Bemisia tabaci species. Sci. Rep. 2015, 5, 17975. [Google Scholar] [CrossRef] [PubMed]
  39. Zhou, B.-G.; Wang, S.; Dou, T.-T.; Liu, S.; Li, M.-Y.; Hua, R.-M.; Li, S.-G.; Lin, H.-F. Aphicidal activity of Illicium verum fruit extracts and their effects on the Acetylcholinesterase and Glutathione S-transferases activities in Myzus persicae (Hemiptera: Aphididae). J. Insect Sci. 2016, 16, 11. [Google Scholar] [CrossRef] [PubMed]
  40. Francis, F.; Vanhaelen, N.; Haubruge, E. Glutathione S-transferases in the adaptation to plant secondary metabolites in the Myzus persicae aphid. Arch. Insect Biochem. Physiol. 2005, 58, 166–174. [Google Scholar] [CrossRef] [PubMed]
  41. Abbott, W.S. A method of computing the effectiveness of an insecticide. J. Econ. Entomol. 1925, 18, 265–267. [Google Scholar] [CrossRef]
  42. Russell, R.M.; Robertson, J.L.; Savin, N.E. POLO: A new computer program for Probit analysis. Bull. Entomol. Soc. Am. 1977, 23, 209–213. [Google Scholar] [CrossRef]
  43. Statistix Statistix 8.1: Analytical Software 2003; Analytical Software: Tallahassee, FL, USA; Available online: http://statistix.com (accessed on 19 January 2017).
  44. SAS Institute. SAS User’s Guide: Statistics; SAS Institute, Cary 2000; SAS: Cary, NC, USA; Available online: www.sas.com (accessed on 19 January 2017).
  45. Livak, K.J.; Schmittgen, T.D. Analysis of relative gene expression data using real-time quantitative PCR and the 2−ΔΔCT Method. Methods 2001, 25, 402–408. [Google Scholar] [CrossRef] [PubMed]
  • Sample Availability: Not available.
Molecules 22 00169 g001 550
Figure 1. Percent corrected cumulative dose-mortality response of R. ferrugineus larvae against (a) coumarin; (b) ethyl cinnamate; (c) diniconazole; (d) isoeugenol; (e) coumarin 6; (f) asarone; (g) eugenol; (h) coniferyl aldehyde; (i) rosmarinic acid; (j) methyl isoeugenol; and (k) methyl eugenol. Bars (means ± SE) followed by different letters are significantly different. (Fisher’s LSD test, α = 0.05).
Figure 1. Percent corrected cumulative dose-mortality response of R. ferrugineus larvae against (a) coumarin; (b) ethyl cinnamate; (c) diniconazole; (d) isoeugenol; (e) coumarin 6; (f) asarone; (g) eugenol; (h) coniferyl aldehyde; (i) rosmarinic acid; (j) methyl isoeugenol; and (k) methyl eugenol. Bars (means ± SE) followed by different letters are significantly different. (Fisher’s LSD test, α = 0.05).
Molecules 22 00169 g001
Molecules 22 00169 g002 550
Figure 2. Expression pattern of detoxification genes of red palm weevil larval midguts in response to different phenylpropanoids by qRT-PCR. Bars (means ± SE) followed by different letters are significantly different (Fisher’s LSD test, α = 0.05).
Figure 2. Expression pattern of detoxification genes of red palm weevil larval midguts in response to different phenylpropanoids by qRT-PCR. Bars (means ± SE) followed by different letters are significantly different (Fisher’s LSD test, α = 0.05).
Molecules 22 00169 g002
Molecules 22 00169 g003 550
Figure 3. Chemical structures of α-asarone 1, eugenol 2, isoeugenol 3, methyl eugenol 4, methyl isoeugenol 5, coumarin 6, coumarin 6 7, coniferyl aldehyde 8, diniconazole 9, ethyl cinnamate 10, and rosmarinic acid 11.
Figure 3. Chemical structures of α-asarone 1, eugenol 2, isoeugenol 3, methyl eugenol 4, methyl isoeugenol 5, coumarin 6, coumarin 6 7, coniferyl aldehyde 8, diniconazole 9, ethyl cinnamate 10, and rosmarinic acid 11.
Molecules 22 00169 g003
Table
Table 1. Dose mortality response of red palm weevil larvae against different phenylpropanoids.
Table 1. Dose mortality response of red palm weevil larvae against different phenylpropanoids.
TreatmentsLD50 (g/L)95% CLχ2Slope ± SE
Coumarin 10.6720.580–0.7784.511.91 ± 0.25
Ethyl cinnamate 26.9746.113–7.9555.602.07 ± 0.25
Diniconazole 29.7568.531–11.1584.421.99 ± 0.25
Isoeugenol 211.56010.080–13.2704.501.98 ± 0.25
Coumarin 6 213.33011.580–15.3501.571.87 ± 0.25
α-Asarone 217.67015.040–20.7505.941.80 ± 0.25
Eugenol 223.26018.020–30.0301.811.43 ± 0.25
Coniferyl aldehyde 227.01019.740–36.9701.581.34 ± 0.25
Rosmarinic acid 3n/an/an/an/a
Methyl isoeugenol 3n/an/an/an/a
Methyl eugenol 3n/an/an/an/a
1 LD50 values were calculated after three days of feeding. 2 LD50 values were calculated after 12 days of feeding. 3 could not attain LD50 values because the treatments could not cause 50% mortality within the course of whole experimentation.
Table
Table 2. Nutritional indices of red palm weevil larvae against different phenylpropanoids.
Table 2. Nutritional indices of red palm weevil larvae against different phenylpropanoids.
TreatmentsADECIECD
Coumarin74.01 ± 0.35 a05.75 ± 0.53 f07.76 ± 0.71 h
Ethyl cinnamate60.02 ± 0.15 b15.01 ± 0.17 e25.01 ± 0.30 g
Diniconazole59.02 ± 0.44 bc16.01 ± 0.11 d27.13 ± 0.20 f
Isoeugenol58.06 ± 0.50 cd16.88 ± 0.24 c29.09 ± 0.62 e
Coumarin 657.71 ± 0.32 de17.34 ± 0.21 bc30.05 ± 0.53 de
α-Asarone57.17 ± 0.49 de17.52 ± 0.19 bc30.66 ± 0.60 cde
Eugenol56.72 ± 0.40 ef17.69 ± 0.30 b31.20 ± 0.73 cd
Coniferyl aldehyde55.92 ± 0.25 fg17.71 ± 0.27 b31.68 ± 0.62 cd
Rosmarinic acid55.66 ± 0.33 g17.91 ± 0.10 b32.19 ± 0.31 c
Methyl isoeugenol55.34 ± 0.45 gh18.81 ± 0.40 a34.02 ± 0.99 b
Methyl eugenol54.33 ± 0.36 hi19.03 ± 0.30 a35.04 ± 0.74 ab
Control53.45 ± 0.28 i19.19 ± 0.21 a35.91 ± 0.58 a
Means ± SE values having the same letter(s) within the column are not significantly different (Fisher’s LSD test, α = 0.05).
Table
Table 3. Target genes and primer sequences used for quantitative PCR expression analysis of detoxification genes from red palm weevil larvae.
Table 3. Target genes and primer sequences used for quantitative PCR expression analysis of detoxification genes from red palm weevil larvae.
Target GeneAccession NoAmplicon SizePrimer 5′–3′ (Forward and Reverse)
Detoxification
Cytochrome P450KT748789118 bpTGGAGAAACACCCGCAAGAA
CGGCGATTTTGCCTACCAAG
Glutathione S-transferaseKR90249692 bpATAGCCAACCACCACTGTCG
CGTTCCTCTTGCCGCTAGTT
EsteraseKT74882270 bpACCTACAAGAATCCGACGCC
ACTCCGAAACTTTGGGCCAT
Housekeeping
beta-ActinKM438516129 bpAAAGGTTCCGTTGCCCTGAA
TGGCGTACAAGTCCTTCCTG

Share and Cite

MDPI and ACS Style

AlJabr, A.M.; Hussain, A.; Rizwan-ul-Haq, M.; Al-Ayedh, H. Toxicity of Plant Secondary Metabolites Modulating Detoxification Genes Expression for Natural Red Palm Weevil Pesticide Development. Molecules 2017, 22, 169. https://doi.org/10.3390/molecules22010169

AMA Style

AlJabr AM, Hussain A, Rizwan-ul-Haq M, Al-Ayedh H. Toxicity of Plant Secondary Metabolites Modulating Detoxification Genes Expression for Natural Red Palm Weevil Pesticide Development. Molecules. 2017; 22(1):169. https://doi.org/10.3390/molecules22010169

Chicago/Turabian Style

AlJabr, Ahmed Mohammed, Abid Hussain, Muhammad Rizwan-ul-Haq, and Hassan Al-Ayedh. 2017. "Toxicity of Plant Secondary Metabolites Modulating Detoxification Genes Expression for Natural Red Palm Weevil Pesticide Development" Molecules 22, no. 1: 169. https://doi.org/10.3390/molecules22010169

Article Metrics

Back to TopTop