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Plant resistance against insects mainly depends on nutrient restriction and toxic metabolites, but the relative importance of nutrition and toxins remains elusive. We examined performance, nutrition ingestion, and transcriptome response of the English grain aphid, Sitobion avenae, feeding on resistant Xiaoyan 22 (XY22) and susceptible Xinong 979 (XN979) wheat cultivars. Aphids had lower body weight and fecundity when feeding on XY22 than on XN979, although the phloem sap of XY22 had a higher nutritive quality (in terms of amino acid:sucrose ratio). Aphids feeding on XY22 also had a lower honeydew excretion rate than those on XN979, suggesting that aphids ingested less phloem sap from XY22. The transcriptome data showed 600 differentially expressed genes (DEGs), and 11 of the top 20 KEGG pathways significantly enriched in DEGs were involved in nutrient metabolism. We found 81 DEGs associated with the metabolism of sugars, lipids, and amino acids, 59 of which were significantly downregulated in aphids feeding on XY22. In contrast, there were 18 DEGs related to detoxifying metabolism, namely eight UDP-glucuronosyltransferases, six cytochromes P450 monooxygenases, one glutathione S-transferase, two ATP-binding cassette transporters, and one major facilitator superfamily transporter; 12 of these were upregulated in the aphids feeding on XY22. Our results indicated that both the quantity and quality of phloem nutrition available to aphids are critical for the growth and development of aphids, and the higher resistance of XY22 is mainly due to the reduction in phloem sap ingested by aphids, rather than toxic metabolites.

In insects, male accessory gland proteins (ACPs) are important reproductive proteins secreted by male accessory glands (MAGs) of the internal male reproductive system. During mating, ACPs are transferred along with sperms inside female bodies and have a significant impact on the post-mating physiology changes of the females. Under sexual selection pressures, the ACPs exhibit remarkably rapid and divergent evolution and vary from species to species. The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a major insect pest of cruciferous vegetables worldwide. Mating has a profound impact on the females’ behavior and physiology in this species. It is still unclear what the ACPs are in this species. In this study, two different proteomic methods were used to identify ACPs in P. xylostella. The proteins of MAGs were compared immediately before and after mating by using a tandem mass tags (TMT) quantitative proteomic analysis. The proteomes of copulatory bursas (CB) in mated females shortly after mating were also analyzed by the shotgun LC-MS/MS technique. In total, we identified 123 putative secreted ACPs. Comparing P. xylostella with other four insect ACPs, trypsins were the only ACPs detected in all insect species. We also identified some new insect ACPs, including proteins with chitin binding Peritrophin-A domain, PMP-22/ EMP/ MP20/ Claudin tight junction domain-containing protein, netrin-1, type II inositol 1,4,5-trisphosphate 5-phosphatase, two spaetzles, allatostatin-CC, and cuticular protein. This is the first time that ACPs have been identified and analyzed in P. xylostella. Our results have provided an important list of putative secreted ACPs, and have set the stage for further exploration of the functions of these putative proteins in P. xylostella reproduction.

Crop resistance and biological control are both considered efficient and environmentally friendly methods of sustainable pest control. In this study, we aimed at investigating the direct influence of four wheat lines with varying resistance level on the life-history traits of the greenbug, Schizaphis graminum, and the mediational effect on the functional response of a predatory ladybird, Propylaea japonica, under laboratory conditions. Results showed that the aphid fitness was the lowest for aphids that had been feeding on wheat line ‘98-10-19’ for one year. These aphids had the longest development time, and least adult mass, minimal mean relative growth rate, and lowest reproductive fitness. In contrast, the aphids that fed on wheat line ‘98-10-30’ were the fittest, with the shortest development time and highest levels of reproductive fitness. The predatory activities of the ladybeetle, especially the adult male significantly decreased following the consumption of aphids belonging to the ‘98-10-19’-acclimated population. However, there were no significant differences in predatory efficiency (net attack frequency) among the four aphid acclimated populations. Our results showed that the wheat line ‘98-10-19’ has a relative higher resistance to S. graminum than the other three wheat lines, which could further decrease the amount of prey available for consumption. However, the ecological effect of the resistance of ‘98-10-19’ to S. graminum posed no negative influence on the biocontrol potential of P. japonica to these aphids, as their predatory efficiency increases at the fourth instar larvae phase.

Insect cuticular hydrocarbons (CHCs) serve as important intersexual signaling chemicals and generally show variation between the sexes, but little is known about the generation of sexually dimorphic hydrocarbons (SDHCs) in insects. In this study, we report the molecular mechanism and biological significance that underlie the generation of SDHC in the German cockroach Blattella germanica. Sexually mature females possess more C29 CHCs, especially the contact sex pheromone precursor 3,11-DimeC29. RNA interference (RNAi) screen against the fatty acid elongase family members combined with heterologous expression of the genes in yeast revealed that both BgElo12 and BgElo24 were involved in hydrocarbon (HC) production, but BgElo24 is of wide catalytic activities and is able to provide substrates for BgElo12, and only the female-enriched BgElo12 is responsible for sustaining female-specific HC profile. Repressing BgElo12 masculinized the female CHC profile, decreased contact sex pheromone level, and consequently reduced the sexual attractiveness of female cockroaches. Moreover, the asymmetric expression of BgElo12 between the sexes is modulated by sex differentiation cascade. Specifically, male-specific BgDsx represses the transcription of BgElo12 in males, while BgTra is able to remove this effect in females. Our study reveals a novel molecular mechanism responsible for the formation of SDHCs and also provide evidences on shaping of the SDHCs by sexual selection, as females use them to generate high levels of contact sex pheromone.

Maternal phenotypic regulations between different generations of aphid species help aphids to adapt to environmental challenges. The pea aphid Acyrthosiphon pisum has been used as a biological model for studies on phenotypic regulation for adaptation, and its alternative phenotypes are typically and physiologically based on maternal effects. We have observed an artificially induced and host-related maternal effect that may be a new aspect to consider in maternal regulation studies using A. pisum. Marked phenotypic changes in the cuticular melanization of daughter A. pisum were detected via tyrosine hydroxylase knockdown in the mothers during their period of host plants alternations. This phenotypic change was found to be both remarkable and repeatable. We performed several studies to understand its regulation and concluded that it may be controlled via the dopamine pathway. The downregulation and phenotypes observed were verified and described in detail. Additionally, based on histological and immunofluorescence analyses, the phenotypic changes caused by cuticular dysplasia were physiologically detected. Furthermore, we found that this abnormal development could not be reversed after birth. Transcriptome sequencing confirmed that this abnormal development represents a systemic developmental failure with numerous transcriptional changes, and chemical interventions suggested that transgenerational signals were not transferred through the nervous system. Our data show that transgenerational regulation (maternal effect) was responsible for the melanization failure. The developmental signals were received by the embryos from the mother aphids and were retained after birth. APTH RNAi disrupted the phenotypic determination process. We demonstrate that non-neuronal dopamine regulation plays a crucial role in the transgenerational phenotypic regulation of A. pisum. These results enhance our understanding of phenotyping via maternal regulation in aphids.

Free amino acids in the phloem sap are the dominant nitrogen source for aphids, but their availability is usually poor. Although some studies have explored the effect of dietary amino acid restriction on aphid performance, little is known about the molecular basis of these effects. Here, we examined the performance and transcriptome of the green peach aphid, Myzus persicae, fed a standard diet (Control diet) or a diet containing 50% of the total amino acids of the Control diet (Half diet). Aphid weight and fecundity were significantly reduced in the Half diet group. Transcriptomic analysis showed that a total of 1460 genes were differentially expressed between the groups were fed on the two diets, which many of them were associated with nutrient and energy metabolism. When feeding on the Half diet, aphids upregulated genes associated with the amino acid biosynthetic pathway (predominantly amino acid biosynthesis genes and some amino acid transporter genes) as well as the cysteine and serine protease genes. Furthermore, these aphids displayed increased expression of genes associated with glycolysis, which could generate intermediates for de novo amino acid biosynthesis. Consistent with this, elevated glucose levels were observed in aphids in the Half diet group. Additionally, the expression levels of several genes associated with hormonal signaling pathway were altered. Several genes related to juvenile hormone and insulin-like peptide (ILP) signaling were downregulated, including Krüppel homolog 1 (Kr-h1) and insulin-like peptide 5 (Ilp5), respectively. In contrast, several genes related to ecdysone signaling were upregulated including broad-complex core protein (Br-c) and shade (Shd). Despite their poor performances, M. persicae adapted to dietary restriction of amino acids, through upregulation of genes involved in amino acid biosynthesis, glycolysis, and protein degradation, as well as by altering the expression level of genes involved in hormone signaling pathways.

Abstract The maternal effects of the English grain aphid, Sitobion avenae on offspring phenotypes and performance on wheat varieties with different resistance traits were examined. We found that both conditioning wheat varieties(the host plant for over 3 months) and transition wheat varieties affected the biological parameters of aphid offspring after they were transferred between wheat varieties with different resistance traits. The conditioning varieties affected weight gain, development time (DT), and the intrinsic rate of natural increase (rm), whereas transition varieties affected the fecundity, rm, net reproductive rate, and fitness index. The conditioning and transition wheat varieties had significant interaction effects on the aphid offspring’s DT, mean relative growth rate, and fecundity. Our results showed that there was obvious maternal effects on offspring when S. avenae transferred bwteen wheat varieties with different resistance level, and the resistance traits of wheat varieties could induce an interaction between the conditioning and transition wheat varieties to influence the growth, development, reproduction, and even population dynamics of S. avenae. The conditioning varieties affected life-history traits related to individual growth and development to a greater extent, whereas transition varieties affected fecundity and population parameters more.

Osteopetrosis is an inherited disorder characterized by increased bone density and brittle bone quality. Degenerative changes often occur after the age of 40 in patients with osteopetrosis. Operative intervention is the primary treatment option if the clinical manifestation of secondary osteoarthritis is severe. A 44-year-old male suffering autosomal dominant osteopetrosis and progressive unilateral hip osteoarthritis required a total hip arthroplasty. However, there were several technical challenges associated with this procedure including creating a femoral medullary canal and developing a Vancouver type B2 periprosthetic femoral fracture postoperatively. To afford some experience for the management of similar cases, we here present our technical solutions to these problems.

Plants emit volatile organic compounds (VOCs) in response to herbivore attack. VOCs emitted from the Chinese cabbage cultivars in response to the damage by the green peach aphid, Myzus persicae, were unknown. Using a solid-phase microextraction-based headspace collection method, we investigated and compared the emissions of VOCs from seven Chinese cabbage cultivars (Qibao, Qingan 80, Lvlong, Yuanbao, Qingan 70, Jinlv, and Lvqiu 66) in response to M. persicae attack. Our results showed that the VOCs emitted from the cultivars Qingan 80 and Yuanbao differed significantly from the other cultivars in response to the attraction of wingless M. persicae. Most importantly, out of the 27 detected compounds, α-caryophyllene was detected only in Qingan 80 and Qibao, but not in the other five cultivars. Among the compounds detected, 2 monoterpene and 12 terpenes were predominant in all cabbage cultivars. Furthermore, the wingless M. persicae showed preference to Qingan 80 while it had the highest nitrogen content among the tested cultivars. Moreover, we found a remarkable relationship among M. persicae attraction, plant nitrogen content, and total volatile emissions. Nitrogen content of the plants has a significant impact on volatile emission and preference behavior of M. persicae. Our results indicate that the wingless M. persicae were efficient in their interspecific host selection with an ability to distinguish plant cultivar differences by leaf nitrogen content. This study will be helpful in understanding aphid host selection, and sets a stage to further study the attractant-based integrated aphid management programs.

Wingless forms of aphids are relatively sedentary, and have a limited ability to migrate or disperse. However, they can drop off hosts or walk away if disturbed, or their food quality or quantity become deteriorated. Earlier, we found that the pea aphid, Acyrthosiphon pisum (Harris, 1776), could use differed strategies to escape danger and locate new host plants. To determine the mechanisms behind the different strategies, we undertook a series of studies including the aphids' host location, energy reserves under starvation, glycogenesis, sugar assimilation, olfactory and probing behaviors. We found that in our controlled laboratory conditions, one strain (local laboratory strain) moved longer distances and dispersed wider ranges, and correspondingly these aphids assimilated more sugars, synthesized more glycogen, and moved faster than another strain (collected from Gansu Province, northwestern China). However, the latter strain could locate the host faster, probed leaves more frequently, and identified plant leaves more accurately than the former strain after they were starved. Our results explained how flightless or wingless insects adapt to fit biotic and abiotic challenges in the complex processes of natural selection.

In natural ecological systems, plants are often simultaneously attacked by both insects and pathogens, which can affect each other’s performance and the interactions can be extended to higher trophic levels, such as parasitoids. The English grain aphid (Sitobion avenae) and powdery mildew (Blumeria graminis f. sp. tritici) are two common antagonists that pose a serious threat to wheat production. Numerous studies have investigated the effect of a single factor (insect or pathogen) on wheat production. However, investigation on the interactions among insect pests, pathogens, and parasitoids within the wheat crop system are rare. Furthermore, the influence of the fungicide, propiconazole, has been found to imitate the natural ecosystem. Therefore, this study investigated the effects of B. graminis on the biological performance of grain aphids and the orientation behavior of its endoparasitic wasp Aphidius gifuensis in the wheat system. Our findings indicated that B. graminis infection suppressed the feeding behavior, adult and nymph weight, and fecundity and prolonged the developmental time of S. avenae. We found that wheat host plants had decreased proportions of essential amino acids and higher content of sucrose following aggravated B. graminis infection. The contents of Pro and Gln increased in the wheat plant tissues after B. graminis infection. In addition, B. graminis infection elicited immune responses in wheat: increase in the expression of defense genes, content of total phenolic compounds, and activity of three related antioxidant enzymes. Moreover, co-infection of B. graminis and S. avenae increased the attraction to A. gifuensis compare to that after infestation with aphids alone. In conclusion, our results indicated that B. graminis infection adversely affected the performance of S. avenae in wheat through restricted nutrition and induced defense response. Furthermore, the preference of parasitoids in such an interactive environment might provide an important basis for pest management control.

In nature, plants have evolved sophisticated defense mechanisms against the attack of pathogens and insect herbivores. Plant volatile-mediated plant-to-plant communication has been assessed in multitrophic systems in different plant species and different pest species. β-ocimene is recognized as an herbivore-induced plant volatile that play an important role in the chemical communication between plants and pests. However, it is still unclear whether β-ocimene can active the defense mechanism of Chinese cabbage Brassica pekinensis against the peach aphid Myzus persicae. In this study, we found that treatment of Chinese cabbage with β-ocimene inhibited the growth of M. persicae in terms of weight gain and reproduction. Moreover, β-ocimene treatment negatively influenced the feeding behavior of M. persicae by shortening the total feeding period and phloem ingestion and increasing the frequency of stylet puncture. When given a choice, winged aphids preferred to settle on healthy Chinese cabbage compared with β-ocimene-treated plants. In addition, performance of the parasitoid Aphidius gifuensis in terms of Y-tube olfaction and landings was better on β-ocimene-treated Chinese cabbage than on healthy plants. Furthermore, β-ocimene significantly increased the expression levels of salicylic acid and jasmonic acid marker genes and the accumulation of glucosinolates. Surprisingly, the transcriptional levels of detoxifying enzymes (CYP6CY3, CYP4, and GST) in aphids reared on β-ocimene-treated Chinese cabbage were significantly higher than those of aphids reared on healthy plants. In summary, our results indicated that β-ocimene can activate the defense response of Chinese cabbage against M. persicae, and that M. persicae can also adjust its detoxifying enzymes machinery to counter the host plant defense reaction.

Plant leaves of different ages differ in nutrients and toxic metabolites and thus exhibit various resistance levels against insect herbivores. However, little is known about the influence of leaf ontogeny on plant resistance to phloem-feeding insects. In this study, we found that the green peach aphid, Myzus persicae, preferred to settle on young cabbage leaves compared with mature or old leaves, although young leaves contained the highest concentration of glucosinolates. Furthermore, aphids feeding on young leaves had higher levels of glucosinolates in their body, but aphids performed better on young leaves in terms of body weight and population growth. Phloem sap of young leaves had higher amino acid:sugar molar ratio than mature leaves, and aphids feeding on young leaves showed two times longer phloem feeding time and five times more honeydew excretion than on other leaves. These results indicate that aphids acquired the highest amount of nutrients and defensive metabolites when feeding on young cabbage leaves that are strong natural plant sinks. Accordingly, we propose that aphids generally prefer to obtain more nutrition rather than avoiding host plant defense, and total amount of nutrition that aphids could obtain is significantly influenced by leaf ontogeny or source-sink status of feeding sites.

The behavior of the greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), is known to be affected by plant volatile cues, but its attraction or repellent to specific volatile cues has not been deeply studied yet. Therefore, the aim of our study was to identify the most attractive plant among cultivars of tomato (Solanum lycopersicum) and eggplant (Solanum melongena) to evaluate the volatiles of plants to identify the chemical compound(s) that attract T. vaporariorum. We speculated that whitefly–host plant interaction primarily depends on plant volatile emissions and that once the plant is damaged, it might attract more whiteflies. Three intact (uninfested) tomato, four intact eggplant cultivars and whitefly infested plants of the most whitefly attractive tomato and eggplant cultivars were examined by behavioral assay experiments for attractiveness to T. vaporariorum and headspace volatile were determined by solid-phase microextraction (SPME) and gas chromatography-mass spectrometry. Whiteflies had the highest preference for the intact eggplant Kuai Yuan Qie (KYQ) among the eggplant and the tomato plant cultivars in bioassay experiments. Although both male and female whiteflies were significantly more attracted to infested KYQ plants than to intact plants, whitefly females did not select conspecific-infested YG plants. The volatile emissions among different plant cultivars in individual species and infested versus intact plants were significantly different. Among these volatiles, identified major green leaf volatiles [(Z)-3-hexen-1-ol] and terpenoids [α-pinene, (E)-β-caryophyllene, α-humulene, azulene] showed a constitutive relationship with the most whitefly preference plants. Our findings provide new insights into the chemical compounds that attract or repel whiteflies.

Aphids exhibit wing polyphenism (winged or wingless) for adaption to predictable or temporally heterogeneous environmental changes; however, the underlying mechanism is still unclear. This morphological change could be stimulated by high aphid density, which in turn could affect octopaminergic signaling in aphids. Octopamine is a neurotransmitter synthesized in insects that can modify their physiological metabolism, locomotion, and other behaviors. We designed experiments to determine whether octopamine functions in wing formation of the pea aphid, Acyrthosiphon pisum (Harris). We determined gene expression of tyramine β-hydroxylase (TβH), a key enzyme in octopamine synthesis at different developmental stages, in different body parts, and in different densities of aphids. We also used TβH RNAi, octopamine receptor agonists (octopamine and synephrine), and an antagonist (mianserin) to modify octopaminergic signaling. We found that transcription of TβH was related to aphid density, which affected the proportion of winged offspring. By manually modifying the mother’s octopaminergic signaling, TβH expression was suppressed, and TβH (enzyme) activity decreased. The proportion of winged offspring was also affected. Our results showed that octopamine could be a link in the wing determination system, as well as environmental stimulation. The RNAi results showed that the decrease of TβH expression increased aphid’s reproduction; however, the decrease of TβH expression declined the numbers of winged-offspring producers, but did not affect the proportion of winged nymphs produced by the winged-offspring producer. In conclusion, the decline in the proportion of winged daughters in the next generation was caused by the decline of winged nymph producers.

The non-protein amino acid β-aminobutyric acid (BABA) can induce plant resistance to a broad spectrum of biotic and abiotic stresses. However, BABA-induced plant resistance to insects is less well-studied, especially its underlying mechanism. In this research, we applied BABA to wheat seedlings and tested its effects on Sitobion avenae (F.). When applied as a soil drench, BABA significantly reduced weights of S. avenae, whereas foliar spray and seed treatment had no such effects. BABA-mediated suppression of S. avenae growth was dose dependent and lasted at least for 7 days. The aminobutyric acid concentration in phloem sap of BABA-treated plants was higher and increased with BABA concentrations applied. Moreover, after 10 days of treatment, the aminobutyric acid content in BABA-treated plants was still higher than that in control treatment. Sitobion avenae could not discriminate artificial diet containing BABA from standard diet, indicating that BABA itself is not a deterrent to this aphid. Also S. avenae did not show preference for control plants or BABA-treated plants. Consistent with choice test results, S. avenae had similar feeding activities on control and BABA-treated plants, suggesting that BABA did not induce antifeedants in wheat seedlings. In addition, aminobutyric acid concentration in S. avenae feeding on BABA-treated plants was significantly higher than those feeding on control plants. Sitobion avenae growth rate was reduced on the artificial diet containing BABA, indicating that BABA had direct toxic effects on this aphid species. These results suggest that BABA application reduced S. avenae performance on wheat seedlings and the mechanism is possibly due to direct toxicity of high BABA contents in plant phloem.

Aphids mainly feed on the phloem sap of host plants and their performance is determined by nutrients and defensive metabolites in their diet. Plant leaves are connected with each other by phloem bundles and thus plant resistance to aphidsmay require the leaves be intact. Excised plant tissues usually have different resistance levels to aphids compared with intact plants; however, the underlying mechanism remains unknown. In this study, we found that the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), strongly preferred detached young cabbage leaves, but exhibited a poorer performance on these leaves than on detached mature leaves. Compared with other leaves, detached young leaves contained higher levels of arginine, asparagine, methionine, and valine, whereas young leaves showed a very poor phloem nutritional quality, reflected by significantly lower amino acid concentrations in aphid honeydew. In contrast, honeydew produced by aphids feeding on detached old leaves and mature leaves contained higher total amino acid concentrations and lower total sugar contents, indicating higher phloemnutritional quality. Because honeydew excretion rates were comparable among aphids feeding on different leaves, the poorer performance of aphids on detached young leaves may be explained by the lower nutritional quality and food quantity that aphids had ingested. On the other hand, levels of most glucosinolates were the highest in detached young leaves and the lowest in detached old leaves, suggesting that the higher attractiveness of young leaves for aphids is not likely determined by glucosinolates. These results suggest that total amino acids that aphids can ingest play a key role in determining aphid performance. Future studies on plant resistance to aphids should focus on both phloem nutritional quality and aphid feeding rate, and should avoid using excised leaves or detached plant tissues. [ABSTRACT FROM AUTHOR]

The behavior of the greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), is known to be affected by plant volatile cues, but its attraction or repellent to specific volatile cues has not been deeply studied yet. Therefore, the aim of our study was to identify the most attractive plant among cultivars of tomato (Solanum lycopersicum) and eggplant (Solanum melongena) to evaluate the volatiles of plants to identify the chemical compound(s) that attract T. vaporariorum. We speculated that whitefly-host plant interaction primarily depends on plant volatile emissions and that once the plant is damaged, it might attract more whiteflies. Three intact (uninfested) tomato, four intact eggplant cultivars and whitefly infested plants of the most whitefly attractive tomato and eggplant cultivars were examined by behavioral assay experiments for attractiveness to T. vaporariorum and headspace volatile were determined by solid-phase microextraction (SPME) and gas chromatography-mass spectrometry. Whiteflies had the highest preference for the intact eggplant Kuai Yuan Qie (KYQ) among the eggplant and the tomato plant cultivars in bioassay experiments. Although both male and female whiteflies were significantly more attracted to infested KYQ plants than to intact plants, whitefly females did not select conspecific-infested YG plants. The volatile emissions among different plant cultivars in individual species and infested versus intact plants were significantly different. Among these volatiles, identified major green leaf volatiles [(Z)-3-hexen-1-ol] and terpenoids [α-pinene, (E)-β-caryophyllene, α-humulene, azulene] showed a constitutive relationship with the most whitefly preference plants. Our findings provide new insights into the chemical compounds that attract or repel whiteflies. [ABSTRACT FROM AUTHOR]

Tomato (Solanum lycopersicum) production is seriously hampered by the infestation of the sweetpotato whitefly, Bemisia tabaci MEAM 1 (Middle East-Asia Minor 1). The infestation behavior of the whiteflies could be affected by the quantity of plant released volatile organic compounds (VOCs) related to nitrogen concentrations of the plant. In this study, we determined the infestation behavior of B. tabaci to the tomato plants that produced different levels of VOCs after application of different levels of nitrogen with a wind tunnel and an olfactometer. We also analyzed the VOCs released from nitrogentreated tomato plants using solid phase microextraction and gas chromatography-mass spectrometry. The results revealed that the production of eight VOCs (b-pinene, (C)- 4-carene, α-terpinene, p-cymene, β-phellandrene, α-copaene, β-caryophyllene, and α-humulene) was reduced after the plants were treated with high levels of nitrogen. However, more whiteflies were attracted to the tomato plants treated with high levels of nitrogen than to the plants treated with normal or below normal levels of nitrogen. These results clearly indicated that nitrogen can change the quality and quantity of tomato plant volatile chemicals, which play important roles in B. tabaci host plant selection. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of pinoresinol diglucoside (PDG) on dexamethasone-induced osteoporosis in rats. Methods: Sixty Wistar rats were randomly and equally divided into normal, control, alendronate and PDG (10, 20 or 40 mg/kg) groups. Bone tissue parameters, including length, transverse diameter, weight, bone mineral content (BMC) and bone mineral density (BMD), were determined using vernier caliper, electronic balance and single photon bone mineral density meter. Serum biochemical indices, including Ca2+, inorganic phosphorus (IP), IL-6, TNF-α and alkaline phosphatase (ALP), were determined using colorimetry and enzyme-linked immunosorbent assay (ELISA). Osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) proteins were detected by Western blot. Results: PDG (10, 20 or 40 mg/kg) increased significantly (p < 0.05 or 0.01) transverse diameter (3.64 - 3.79 vs. 3.31 mm), weight (0.73 - 0.78 vs. 0.67 g), BMC (0.16 - 0.23 vs. 0.12 g/cm), BMD (0.27 - 0.35 vs. 0.22 g/cm²) of right femur, serum Ca2+ level (2.16 - 2.39 vs. 1.94 mmol/L), and OPG level of left femur, compared with those in the control group. PDG (10, 20 or 40 mg/kg) reduced significantly (p < 0.05 or 0.01) serum IP (1.34 - 1.14 vs. 1.76 mmol/L), IL-6 (103.25 - 95.38 vs. 108.74 ng/L), TNF-a (87.46 - 82.05 vs. 92.38 ng/L), ALP (334.79 - 276.32 vs. 486.45 U/L) levels or activities, and RANKL level of left femur, compared with those in the control group. Conclusion: PDG exhibits a protective effect on dexamethasone-induced osteoporosis by increasing bone mass and regulating bone metabolism. Thus, PDG may be a candidate drug for treating osteoporosis. [ABSTRACT FROM AUTHOR]