Novel Hydroxy- and Epoxy-cis-Jasmone and Dihydrojasmone Derivatives Affect the Foraging Activity of the Peach Potato Aphid Myzus persicae (Sulzer) (Homoptera: Aphididae)

Jasmonates show great potential in sustainable agriculture due to their various roles in natural mechanisms of plant defense, and because they are non-toxic, non-mutagenic, and easily metabolized. The aim of the study was to explore structure–activity relationships of dihydrojasmone, cis-jasmone, and their derivatives at the plant–aphid interface. We focused on the behavioral responses of aphids, following the exogenous application of natural jasmonates and their derivatives to the host plants. Aphid probing behavior was examined using an electrical penetration graph technique (EPG). The chemoenzymatic transformation of cis-jasmone and the activity of two new derivatives are described. The application of cis-jasmone, dihydrojasmone, the hydroxyderivatives, epoxyderivatives, and alkyl-substituted δ-lactones hindered the foraging activity of Myzus persicae (Sulz.) (Hemiptera: Aphididae) during early stages of probing at the level of non-phloem tissues. The application of saturated bicyclic epoxy-δ-lactone enhanced plant acceptance by M. persicae. Jasmonate derivatives containing a hydroxy group, especially in correlation with a lactone ring, were more active than natural compounds and other derivatives studied. Jasmonates of the present study are worth considering as elements of sustainable aphid control as components of the “push–pull” strategy

Chemo-Enzymatic Synthesis of Optically Active γ- and δ-Decalactones and Their Effect on Aphid Probing, Feeding and Settling Behavior.

The enantiomerically enriched γ- and δ-decalactones (4a and 4b) were prepared from corresponding racemic primary-secondary 1,4- and 1,5-diols (1a and 1b), as products of enzymatic oxidation catalyzed by different alcohol dehydrogenases. The results of biotransformations indicated that the oxidation processes catalyzed by alcohol dehydrogenase (HLADH), both isolated from horse liver and recombinant in Escherichia coli, were characterized by the highest degree of conversion with moderate enantioselectivity of the reaction. Useful, environmentally friendly extraction procedure of decalactones (4a and 4b) based on hydrodistillation using a Deryng apparatus was developed. Both racemic lactones (4a and 4b), as well as their enantiomerically enriched isomers, were tested for feeding deterrent activity against Myzus persicae. The effect of these compounds on probing, feeding and settling behavior of M. persicae was studied in vivo. The deterrent activity of decalactones (4a and 4b) against aphids depended on the size of the lactone ring and the enantiomeric purity of the compounds. δ-Decalactone (4b) appeared inactive against M. persicae while γ-decalactone (4a) restrained aphid probing at ingestional phase. Only (-)-(S)-γ-decalactone (4a) had strong and durable (i.e. lasting for at least 24 hours) limiting effect, expressed at phloem level

Primitive Reflex Activity in Relation to Motor Skills in Healthy Preschool Children

Psychomotor development in the first year of life is possible due to activity and then integration of primitive (neonatal) reflexes. The presence of active primitive reflexes (APRs) in preschool and school-aged children indicates neuromotor immaturity. Studies show dependencies between the preserved activity of primary reflexes and developmental problems such as learning difficulties (problems with reading, writing, reduced mathematics skills, and dyslexia), difficulties with coordination, and attention deficit. The primary purpose of this study is to present the activity of three tonic reflexes in a sample of 112 Polish children aged 4–6 in relation to their motor skills. The children were examined for the presence of the asymmetric tonic neck reflex (ATNR), symmetric tonic neck reflex (STNR), and tonic labyrinthine reflex (TLR). Motor performance was examined with the MOT 4–6. Statistical analysis shows an inverse correlation between the score in the test of reflexes and motor efficiency (MOT 4–6) at p < 0.05 (−0.33). Children with increased reflex activity presented a lower level of motor efficiency. The multiple regression model showed that with the older age of the child and the decrease in the level of reflex activity, the motor skills of children improve. Thus, there is a need for early screening of primitive reflexes in children. Properly selected exercises and therapeutic activities aimed at integrating APRs in children with developmental difficulties can improve their motor skills, perceptual abilities, and emotional behavior

Primitive Reflex Activity in Relation to the Sensory Profile in Healthy Preschool Children

The presence of active primitive reflexes (APRs) in healthy preschool children can be an expression of immaturity in the functioning of the nervous system. Their trace presence may not significantly affect the quality of child functioning. They may also undergo spontaneous and complete integration within the stages of child development. However, a higher level of active reflexes and their significant number can disturb sensory-motor development and lead to additional problems in a child’s motor activities, social life, and education. The main purpose of this study was to examine the types of sensory disorders noticed by parents of children, if any, that accompany the presence of active primitive reflexes. The study was conducted in a group of 44 preschool children (aged 4–6 years). The sensory profile of children was determined using Child Sensory Profile Cards, and Sally Goddard-Blythe tests were used to measure their primitive reflexes. The coefficient of determination (R-squared) indicated that the level of reflex activity was most strongly associated with sensory disorders such as dyspraxia, sensory-vestibular disorders, and postural disorders, at a level of p < 0.005. The obtained research results show that the examination of non-integrated reflexes might be a screening tool for children of preschool age. Knowledge of the subject of reflexes and their impact on sensory-motor functions may contribute to more accurate diagnoses of the causes of problems and higher effectiveness of possible therapy

Effect of decalactones and their pure enantiomers (1–6) on the settling preferences of <i>Myzus persicae</i> in the choice test.

<p>1—(±)-δ-decalactone (<b>4b</b>), 2—(+)-(<i>R</i>)-δ-decalactone (<b>4b</b>), 3—(–)-(<i>S</i>)-δ-decalactone (<b>4b</b>), 4—(±)-γ-decalactone (<b>4a</b>), 5—(+)-(<i>R</i>)-γ-decalactone (<b>4a</b>), 6—(–)-(<i>S</i>)-γ-decalactone (<b>4a</b>). Data are expressed as values of indices of deterrence (<i>DI</i>). * <i>P <</i> 0.05 (Student <i>t</i>-test).</p

Alteration of <i>Myzus persicae</i> behaviour during probing after exposure to decalactones^a.

<p>Alteration of <i>Myzus persicae</i> behaviour during probing after exposure to decalactones<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0146160#t005fn001" target="_blank">^a</a>.</p

The composition (in % according to GC) of products mixture in the course of preparative oxidation of racemic decane-1,4-diol (1a) catalyzed by alcohol dehydrogenases.

<p>The composition (in % according to GC) of products mixture in the course of preparative oxidation of racemic decane-1,4-diol (1a) catalyzed by alcohol dehydrogenases.</p

Space structures and chemical shifts of signals from protons H-2 and H-5 in hemiacetals 2a and 3a.

<p>Space structures and chemical shifts of signals from protons H-2 and H-5 in hemiacetals 2a and 3a.</p

The composition (in % according to GC) of products mixture in the course of preparative oxidation of racemic decane-1,5-diol (1b) catalyzed by alcohol dehydrogenases.

<p>The composition (in % according to GC) of products mixture in the course of preparative oxidation of racemic decane-1,5-diol (1b) catalyzed by alcohol dehydrogenases.</p

Analysis of <i>Myzus persicae</i> probing activities on plants after application of decalactones, expressed as the proportion of behavioural events in individual aphids (numbers on X axis represent individual aphids).

<p>np–no probing, pathway phase–probing in parenchymatous tissues, phloem phase–salivation and sap ingestion of phloem sap.</p