Specific recognition, detoxification and metabolism of pyrrolizidine alkaloids by the polyphagous arctiid Estigmene acrea

Evidence is presented that the polyphagous arctiid Estigmene acrea is well adapted to sequester and specifically handle pyrrolizidine alkaloids of almost all known structural types representative of the major plant families with pyrrolizidine alkaloid-containing species, i.e. Asteraceae with the tribes Senecioneae and Eupatorieae, Boraginaceae, Fabaceae, Apocynaceae and Orchidaceae. The adaptation of E. acrea to pyrrolizidine alkaloids includes a number of specialized characters: (i) highly sensitive recognition of alkaloid sources by pyrrolizidine alkaloid-specific taste receptors; (ii) detoxification of pyrrolizidine alkaloids by N-oxidation catalyzed by a specific flavin-dependent monooxygenase; (iii) transfer and maintenance of all types of pyrrolizidine N-oxides through all developmental stages; (iv) conversion of the various structures into the male courtship pheromone hydroxydanaidal most probably through retronecine and insect specific retronecine esters (creatonotines) as common intermediates; (v) specific integration into mating behavior and defense strategies. Toxic otonecine derivatives, e.g. the senecionine analogue senkirkine, which often accompany the common retronecine derivatives and which cannot be detoxified by N-oxidation do not affect the development of E. acrea larvae. Senkirkine is not sequestered at all. Non-toxic 1,2-saturated platynecine derivatives that frequently occur together with toxic retronecine esters are sequestered and metabolized to hydroxydanaidal, indicating the ability of E. acrea to aromatize saturated pyrrolizidines. Although pyrrolizidine alkaloids, even if they are offered continuously at a high level (2%) in the larval diet, are non-toxic, E. acrea larvae are not able to develop exclusively on a pyrrolizidine alkaloid-containing plant like Crotalaria. Therefore, E. acrea appears to be specifically adapted to exploit pyrrolizidine alkaloid-containing plants as "drug source" but not as a food source.     

Acquisition, transformation and maintenance of plant pyrrolizidine alkaloids by the polyphagous arctiid Grammia geneura

The polyphagous arctiid Grammia geneura appears well adapted to utilize for its protection plant pyrrolizidine alkaloids of almost all known structural types. Plant-acquired alkaloids that are maintained through all life-stages include various classes of macrocyclic diesters (typically occurring in the Asteraceae tribe Senecioneae and Fabaceae), macrocyclic triesters (Apocynaceae) and open-chain esters of the lycopsamine type (Asteraceae tribe Eupatorieae, Boraginaceae and Apocynaceae). As in other arctiids, all sequestered and processed pyrrolizidine alkaloids are maintained as non-toxic N-oxides. The only type of pyrrolizidine alkaloids that is neither sequestered nor metabolized are the pro-toxic otonecine-derivatives, e.g. the senecionine analog senkirkine that cannot be detoxified by N-oxidation. In its sequestration behavior, G. geneura resembles the previously studied highly polyphagous Estigmene acrea. Both arctiids are adapted to exploit pyrrolizidine alkaloid-containing plants as "drug sources". However, unlike E. acrea, G. geneura is not known to synthesize the pyrrolizidine-derived male courtship pheromone, hydroxydanaidal, and differs distinctly in its metabolic processing of the plant-acquired alkaloids. Necine bases obtained from plant acquired pyrrolizidine alkaloids are re-esterified yielding two distinct classes of insect-specific ester alkaloids, the creatonotines, also present in E. acrea, and the callimorphines, missing in E. acrea. The creatonotines are preferentially found in pupae; in adults they are largely replaced by the callimorphines. Before eclosion the creatonotines are apparently converted into the callimorphines by trans-esterification. Open-chain ester alkaloids such as the platynecine ester sarracine and the orchid alkaloid phalaenopsine, that do not possess the unique necic acid moiety of the lycopsamine type, are sequestered by larvae but they need to be converted into the respective creatonotines and callimorphines by trans-esterification in order to be transferred to the adult stage. In the case of the orchid alkaloids, evidence is presented that during this processing the necine base (trachelanthamidine) is converted into its 7-(R)-hydroxy derivative (turneforcidine), indicating the ability of G. geneura to introduce a hydroxyl group at C-7 of a necine base. The creatonotines and callimorphines display a striking similarity to plant necine monoesters of the lycopsamine type to which G. geneura is well adapted. The possible function of insect-specific trans-esterification in the acquisition of necine bases derived from plant acquired alkaloids, especially from those that cannot be maintained through all life-stages, is discussed.     

Sexual differences in postingestive processing of dietary protein and carbohydrate in caterpillars of two species

Previous studies indicated that female Heliothis virescens and Estigmene acrea caterpillars use both feeding and postingestive processing as mechanisms to meet nutrient demands. We present utilization and nutrient budget data on the postingestive partitioning of nutrients into pre- and postabsorptive components. Both species utilized carbohydrate efficiently except at very high ingestion rates. Of the carbohydrate utilized, more was unaccounted for as intake increased, and we assume the material unaccounted for served as a respiratory substrate. In contrast, the pattern of nitrogen utilization differed between the species. Larval H. virescens efficiently retained nitrogen except at very high ingestion rates, whereas E. acrea progressively increased nitrogen egestion in response to increased nitrogen ingestion. Overall, females of both species utilized nitrogen more efficiently than did males at most ingestion levels, thus contributing to the greater protein-derived growth we previously reported. In addition, for H. virescens, protein and amino acids accounted for a small proportion of fecal nitrogen so that most of the fecal nitrogen was of a postabsorptive nature. In contrast, nitrogen excreted by E. acrea could be partitioned into both pre- and postabsorptive components. The manner of postingestive processing by these two species reflects differences in their larval diet.     

Response of tomato (Lycopersicon esculentum Mill.) growth to different phosphorous levels and sowing dates

A field trail was carried out at the University of Agriculture Peshawar during spring, 2013 in order to evaluate the effect of different levels of phosphorus fertilizer and various planting times on the growth and development of tomato. The main objective of the research work was to investigate the best sowing time for tomato in combination with suitable dose of P fertilizer in order to get maximum yield of tomato in the climatic conditions of Peshawar. RCB Design with split plot arrangements was used in the trail. The main factor (phosphorous levels of 0, 90, 110, 130) was allotted to main plots while sowing dates in sub plots. A total twelve treatment were replicated thrice. Maximum days to flowering (39.583?days) and fruiting (46.167?days) obtained in the late sowing. Minimum days to flowering (39), minimum days to fruiting (38.778?days) were taken by the early sowing. Maximum number of branches (27.778), maximum fruit length (6.0222), maximum fruit with (6.1667), maximum fruit yield (24.653?tons?ha^?1) was produced when the plot fertilize with 130?kg?P?ha^?1. Maximum number of fruit?plant^?1 (29.778) were produced with application of 130?kg?P?ha^?1, minimum number of fruits (23.667?cm), fruit width (3.778?cm), fruit length (4.3667?cm), plant height (56.300?cm) were obtained from the controlled treatment. Among the various treatment studied in experiment, it is concluded that early planting of the tomato in the summer season i.e. in the start of March and the use of higher dose of P (130?kg?P?ha^?1) is very beneficial for the excellent growth, development and yield of tomato crop.     

Diel periodicity and influence of age and mating on female sex pheromone titre in Estigmene acrea (Lep., Arctiidae)

Abstract:  Calling behaviour, diel periodicity, and effect of age and mating on female sex pheromone titre in Estigmene acrea (Drury) were studied under laboratory conditions. Forty-five per cent of females started calling during the first scotophase, but the highest number of calling females was observed during the second, third and fourth scotophases. Calling behaviour occurred from the third hour after dark until just before the end of the scotophase. However, females exhibited a bimodal pattern of calling with the first peak occurring between 4 and 6 h and a second peak at 10 h after the onset of scotophase. The mean onset of calling time differed significantly with age. Older females showed a tendency to call longer, but there was no significant difference. The amount of (Z,Z)-3,6-cis-9, 10-epoxyheneicosadiene in females was quantified from the first scotophase following emergence, until the fifth scotophase. Glands of 0-day-old females presented a higher content of pheromone compared with that found in glands of 1-, 2-, 3- and 4-day-old females. Pheromone titre was determined at 2-h intervals throughout the third scotophase and photophase. (Z,Z)-3,6-cis-9,10-epoxyheneicosadiene was found in the gland during the scotophase as well as the photophase. However, there was no consistent pattern of pheromone production throughout the scotophase or photophase. Mated females of E. acrea produced significantly less pheromone than virgin females.     

软儿梨果酒发酵过程中挥发性风味物质变化分析

软儿梨是西北地区特有的一种“冻果”产品,酸甜可口、果香浓郁,是酿造果酒的上乘原料。为明确果酒发酵过程中果香的保留情况,并探究发酵时间的延长对软儿梨果酒品质的影响,以青海省民和县软儿梨冻果为原料,基于带皮渣发酵工艺,先采用顶空固相微萃取（solid?phase microextraction, SPME）,再结合气相色谱?质谱联用技术（gas chromatography?mass spectrometry, GC?MS）对原汁（0 d）、前发酵（7、14、28 d）、后发酵（100 d）3个不同时期样品中挥发性风味物质进行了动态跟踪分析,并结合相对气味活度值（relative odor activity value,ROAV）和主成分分析（principal component analysis,PCA）法分别探讨了软儿梨果酒原果香味保留情况和后发酵时间的延长对果酒风味的影响。结果显示：整个发酵过程共检出88种挥发性化合物,其中酯类33种、醇类29种、酸类6种、萜烯类7种以及13种其他类化合物,且风味物质的总含量随发酵的进行呈先上升后略有下降的趋势。ROAV结果表明：软儿梨原汁关键风味物质共8种,分别是丁酸乙酯、己酸乙酯、2?甲基丁酸乙酯、正辛醇、大马士酮、芳樟醇、丁香酚和癸醛;其中果香物质己酸乙酯、正辛醇、芳樟醇、丁香酚和大马士酮在果酒发酵中得到了很好的保留,是决定软儿梨果酒风味的关键物质。主成分分析表明：发酵初期主要的香气贡献物质是具有水果香的丁酸乙酯、3?羟基丁酸乙酯、2?甲基丁酸乙酯;发酵100 d时,乙酸乙酯、α?松油醇、柠檬烯和芳樟醇对香气贡献较大,这些香气化合物共同赋予软儿梨果酒幽香清雅、馥香浓郁的独特风味品质。研究获得了软儿梨果酒关键风味物质及其在不同发酵阶段特征风味物质的变化规律,可为研发高品质软儿梨果酒产品、改进软儿梨果酒发酵工艺提供理论支撑和参考。     

Melanogenesis inhibitory activity of monoterpene glycosides from gardeniae fructus

A new iridoid glycoside, 10-O-(4″-O-methylsuccinoyl)geniposide (7), and two new pyronane glycosides, jasminosides Q and R (13 and 14, resp.), along with nine known iridoid glycosides, 1-6 and 8-10, and two known pyronane glycosides, 11 and 12, were isolated from a MeOH extract of Gardeniae Fructus, the dried ripe fruit of Gardenia jasminoides (Rubiaceae). The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses and comparison with literature. Upon evaluation of compounds 1-14 on the melanogenesis in B16 melanoma cells induced with α-melanocyte-stimulating hormone (α-MSH), three compounds, i.e., 6-O-p-coumaroylgeniposide (3), 7, and 6'-O-sinapoyljasminoside (12), exhibited inhibitory effects with 21.6-41.0 and 37.5-47.7% reduction of melanin content at 30 and 50?μM, respectively, with almost no toxicity to the cells (83.7-106.1% of cell viability at 50?μM).     

Effect of melatonin and gibberellic acid foliar application on the yield and quality of Jumbo blackberry species

Not many chemical hormone studies does exist in our country especially in berry fruits. Foliar application of melatonin and gibberellic acid hormones was performed in 2016 and 2017 in order to analyze the effects of different doses of hormone applications on fruit quality and yield. Pheonologic, pomological and some bioactive content analyses of these hormones were studied. According to the research results, while M?+?GA10 ppm (240.50; 3.9) and M?+?GA 5?ppm (226.50; 3.6) applications have the highest fruit number and weight (g), the highest fruit size was obtained from GA 5?ppm (21.21?mm fruit length, 16.56?mm fruit width) and M 10?ppm (21.10?mm fruit length, 16.20?mm fruit width) chemical applications in Jumbo blackberry species. The highest values in Ph, soluble solid content (SSC) and titratable acidity averages were obtained from GA 5?ppm (3.69; 10.80; 2.42) and GA 10?ppm (3.68; 10.70; 2.40) applications; the highest total antioxidant activity in bioactive characteristics averages was found in G 10?ppm 143.21?mg/g, the highest total phenolics was identified in G 5?ppm 72.68?ppm/GAE and the highest total flavonoids was determined in G 10?ppm 4925.75?ppm/QE.     

Enhanced production of pink pineapple mealybug,Dysmicoccus brevipes (Hemiptera: Pseudococcidae)

A mass rearing program was developed for the pink pineapple mealybug (PPM), Dymsicoccus brevipes (Cockerell) (Hemiptera: Pseudococcidae), to provide host material for producing the encyrtid parasitoid Anagyrus ananatis (Gahan). PPM individuals produce honeydew that accumulates on heavily infested squash and entraps crawlers and older instars. A new protocol was tested to reduce accumulated honeydew with minimal mortality to PPM. Butternut and kobocha squash were placed in rearing containers and covered with coarse vermiculite (>2.36?mm diameter) after being infested with PPM. Use of vermiculite removed the honeydew from the squash surface. PPM produced using vermiculite were easily harvested from the host squash, but mealybugs produced on squash without vermiculite were embedded within the honeydew. When individual kobocha squash fruit were inoculated with 300–400 mature PPM adults (>0.6?mm length), about 700 adult PPM (appropriate for A. ananatis production) were produced for each dollar value (USA) of squash fruit (i.e., ～1500?PPM per individual squash).     

Development and characterization of 20 new polymorphic microsatellite markers from Mangifera indica (Anacardiaceae)

? Premise of the study: Twenty microsatellite loci for mango (Mangifera indica), an important commercial fruit tree in East Asia, were developed to evaluate the genetic diversity and identification of cultivars. ? Methods and Results: The 20 new microsatellite markers were isolated from mango using a magnetic bead enrichment method, and polymorphisms were identified in 22 mango cultivars. The number of alleles ranged from one to nine, with expected heterozygosity ranging from 0 to 0.826. The polymorphism information content ranged from 0 to 0.756 with a mean of 0.525. ? Conclusions: These new microsatellite loci should be useful and convenient for further studies of the genetic diversity and identification of cultivars in mango.     

Differential Suppression of Ethylene Biosynthesis and Receptor Genes in ‘Golden Delicious’ Apple by Preharvest and Postharvest 1-MCP Treatments

Harvista?, a sprayable formulation of 1-methylcyclopropene (1-MCP), has recently been developed for preharvest use on horticultural products, whereas SmartFresh? is a widely used 1-MCP treatment for products after harvest. The effects of Harvista? on apple fruit ripening when sprayed at different maturities and on expression patterns of ethylene biosynthesis and receptor genes during storage have been investigated. Harvista? applied to on-tree maturing apple fruit at an average starch pattern index of 2.5 resulted in a higher at-harvest firmness value compared with those treated at a starch pattern index of 1.5 and 3.5. This indicates that the timing of the Harvista? application is critical. An application of Harvista? led to better postharvest fruit firmness retention as well as reduced ethylene production. In addition, both preharvest and postharvest 1-MCP treatments resulted in contrasting responses in the expression patterns of two ethylene biosynthesis genes and in differentially suppressing effects on four ethylene receptor genes. Furthermore, the combined application of Harvista? + SmartFresh? resulted in greater fruit firmness retention and longer ethylene suppression. The expression profiles of these genes during on-tree fruit maturation prior to Harvista? application were also characterized. Different regulation patterns of receptor genes could contribute to differential effects by 1-MCP treatments. The potential roles of Harvista? to manipulate the ripening process as well as the molecular mechanism influencing 1-MCP treatment efficacy are discussed.     

Determination of morphological variation in subspecies of Isatis glauca Aucher ex Boiss. from Central Anatolia

Isatis glauca Aucher ex Boiss. has four subspecies: glauca, galatica Y?ld?r?ml?, sivasica (Davis) Y?ld?r?ml? and iconia (Boiss.) Davis, naturally growing in Turkey. In this study, 77 accessions from nine I. glauca ssp. populations were characterised in terms of variation in morphological characters, including the number of branches per plant, plant height, diameter of stem base, diameter of middle stem, diameter of apical stem, width and length of fruit, length of fruit stalk, fruit shape, fruit base shape, fruit apices shape, loculus, ondulation, apical process of fruit, fruit weight, basal length of fruit, apical length of fruit, wing width of fruit, loculus length, loculus width, length of seed, dorsal width of seed, lateral width of seed and seed weight. The number of branches had the highest value of coefficient of variation (CV), 0.21–0.86, while the fruit width had the lowest value of CV 0.08–0.20. According to Pearson’s correlation and multiple regression analyses, eco-geographical factors had a substantial effect on morphological variation. A principal component analysis explained 90.61 % of morphological variation through the study of five extracted components. A dendrogram, which was constructed according to the between-group linkages method, based on squared Euclidean distances, represented a hierarchical cluster analysis of 77 accessions. The results of the principal coordinate analysis, which showed differentiation according to morphological characters between nine populations, were consistent with the dendrogram. Consequently, morphological variation of I. glauca ssp. and the significant effects of eco-geographical factors on its morphological variation were discussed.     

Genetic characterization of the Ma locus with pH and titratable acidity in apple

Apple fruit flavor is greatly affected by the level of malic acid, which is the major organic acid in mature apple fruit. To understand the genetic and molecular basis of apple fruit acidity, fruit juice pH and/or titratable acidity (TA) were measured in two half-sib populations GMAL 4595 [Royal Gala?×?PI (Plant Introduction) 613988] and GMAL 4590 (Royal Gala?×?PI 613971) of 438 trees in total. The maternal parent Royal Gala is a commercial variety and the paternal parents are two M. sieversii (the progenitor species of domestic apple) elite accessions. The low-acid trait segregates recessively and the overall acidity variations in the two populations were primarily controlled by the Ma (malic acid) locus, a major gene discovered in the 1950s (Nybom in Hereditas 45:332?C350, 1959) and later mapped to linkage group 16 (Maliepaard et al. in Theor Appl Genet 97:60?C73, 1998). The allele Ma has a strong additive effect in increasing fruit acidity and is incompletely dominant over ma. QTL (quantitative trait locus) analyses in GMAL 4595 mapped the major QTL Ma in both Royal Gala and PI 613988, the effects of which explained 17.0?C42.3% of the variation in fruit pH and TA. In addition, two minor QTL, tentatively designated M2 and M3, were also detected for fruit acidity, with M2 on linkage group 6 of Royal Gala and M3 on linkage group 1 of PI 613988. By exploring the genome sequences of apple, eight new simple sequence repeat markers tightly linked to Ma were developed, leading to construction of a fine genetic map of the Ma locus that defines it to a physical region no larger than 150?kb in the Golden Delicious genome.     

Visual neuroscience: how flies segregate moving objects from the optic flow field

Moving animals often have difficulty detecting moving objects because self-generated optic flow patterns confound image motion. The new hypothesis of 'regressive motion salience' reveals simple rules used by fruit?flies.     

Morphogenetic effects of alkaloidal metabolites on the development of the coremata in the salt marsh moth, Estigmene acrea (Dru.) (Lepidoptera: Arctiidae)

Pyrrolizidine alkaloids (PAs) play a fundamental role in the sexual biology of the salt marsh moth Estigmene acrea. They are precursors for the male courtship pheromone hydroxydanaidal and they stimulate the growth and development of male pheromone-disseminating organs called coremata. Yet larval Estigmene are polyphagous and feed only sporadically on PA-containing plants and those they utilize contain different classes of PAs. The various PAs ingested are hydrolyzed to the common necine metabolite retronecine and re-esterified to insect-specific alkaloids from which the male pheromone hydroxydanaidal is synthesized. Given this complex metabolic pathway, we investigated the role of retronecine and the insect-specific alkaloids that stem from it as morphogens stimulating corematal growth. Retronecine fed to terminal instar larvae in a standard caterpillar diet stimulated corematal growth. It also stimulated corematal growth when it was injected into the hemolymph of larvae. These results indicate that this common PA metabolite, and/or the insect specific alkaloids produced from it, function as corematal morphogens. The parental forms (alkaloids ingested from the plant) are not strictly necessary for corematal growth. Stimulation of the PA receptors on the galea and ingestion process are also not critical to corematal development. Since the insect-specific alkaloids are the direct precursors for the male courtship pheromone, it is argued that their level is the best indicator of the ultimate pheromone titer and would provide the most accurate developmental signal. The effects of alkaloidal metabolites as morphogens in E. acrea are compared to those for the South Asian arctiines Creatonotus gangis and C. transiens in which the developmental role of PAs was first discovered.     

Biomechanical acclimation: flying cold

Why are animals reared at colder temperatures larger? A new study shows that fruit flies reared at lower temperatures are better able to fly in the cold.     

硕叶杜英,中国杜英科一新记录种

文章报道了产自中国云南杜英科杜英属一新记录种,硕叶杜英(Elaeocarpus grandifolius Kurz),并对硕叶杜英叶绿体基因组进行了测序和系统发育分析。该种与近缘种毛果杜英(Elaeocarpus rugosus)的区别是叶基部渐狭或下延,花瓣外部被锈色短柔毛,核果被锈色短柔毛,该种与水石榕(Elaeocarpus hainanensis)的区别是叶片长圆形或卵圆形,核果椭球形。