Publications by authors named "M Laura Giorgini"

65 Publications

Zucchini Plants Alter Gene Expression and Emission of ()-β-Caryophyllene Following Infestation.

Front Plant Sci 2020 8;11:592603. Epub 2021 Jan 8.

Department of Agricultural Sciences, University of Naples Federico II, Naples, Italy.

Zucchini ( L.) is widely cultivated in temperate regions. One of the major production challenges is the damage caused by (Homoptera: Aphididae), a polyphagous aphid, which can negatively affect its host plant, both directly by feeding and indirectly by vectoring viruses. To gain insights into the transcriptome events that occur during the zucchini-aphid interaction and to understand the early-to-late defense response through gene expression profiles, we performed RNA-sequencing (RNA-Seq) on zucchini leaves challenged by (24, 48, and 96 h post-infestation; hpi). Data analysis indicated a complex and dynamic pattern of gene expression and a transient transcriptional reconfiguration that involved more than 700 differentially expressed genes (DEGs), including a large number of defense-related genes. The down-regulation of key genes of plant immunity, such as leucine-rich repeat (LRR) protein kinases, transcription factors, and genes associated with direct (, protease inhibitors, cysteine peptidases, etc.) and indirect (, terpene synthase) defense responses, suggests the aphid ability to manipulate plant immune responses. We also investigated the emission of volatile organic compounds (VOCs) from infested plants and observed a reduced emission of ()-β-caryophyllene at 48 hpi, likely the result of aphid effectors, which reflects the down-regulation of two genes involved in the biosynthesis of terpenoids. We showed that ()-β-caryophyllene emission was modified by the duration of plant infestation and by aphid density and that this molecule highly attracts , a parasitic wasp of . With our results we contributed to the identification of genes involved in cucurbit plant interactions with phloem feeders. Our findings may also help pave the way toward developing tolerant zucchini varieties and to identify molecules for sustainable management of harmful insect populations.
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http://dx.doi.org/10.3389/fpls.2020.592603DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7820395PMC
January 2021

Biology and Prevalence in Northern Italy of (Diptera, Pipunculidae), a Parasitoid of (Hemiptera, Aphrophoridae), the Main Vector of in Europe.

Insects 2020 Sep 7;11(9). Epub 2020 Sep 7.

Dipartimento di Scienze Agrarie, Forestali e Alimentari, Università degli Studi di Torino, Largo Paolo Braccini, 2, 10095 Grugliasco, Italy.

The meadow spittlebug, (L.) (Hemiptera Aphrophoridae), the main vector of Wells et al. in Europe, has few known natural enemies. The endoparasitoid (Fallén) (Diptera, Pipunculidae) was first noticed a long time ago but very little is known about its biology and prevalence. In this study, the presence and prevalence of were investigated in different regions of northern Italy, both in plain-foothill and montane zones. Parasitic larvae were identified by the dissection of spittlebug adults, and (Fallén), and by a new species-specific molecular tool targeting the and genomic regions, developed in this work. A small-scale rearing was set up to gain information on the life cycle of on its main host . During the four-year investigation (2016-2019) the pipunculid parasitoid displayed low prevalence, reaching a maximum parasitization rate of 17.5% (calculated over the adult spittlebug season) in vineyards of the Piemonte region. Over the whole period, no significant difference in the prevalence was found between male and female spittlebugs. Collected data and rearing observations suggest that is monovoltine and synchronous with , laying eggs in newly emerged adults, developing as an endoparasitoid through two larval stages during the whole summer, and overwintering as a pupa in the soil.
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http://dx.doi.org/10.3390/insects11090607DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7564977PMC
September 2020

Electrophysiological and behavioural response of Philaenus spumarius to essential oils and aromatic plants.

Sci Rep 2020 02 20;10(1):3114. Epub 2020 Feb 20.

National Research Council of Italy, Institute for Sustainable Plant Protection, Department of Biology, Agriculture and Food Sciences, Portici, Na, 80055, Italy.

The meadow spittlebug, Philaenus spumarius, is a highly polyphagous widespread species, playing a major role in the transmission of the bacterium Xylella fastidiosa subspecies pauca, the agent of the "Olive Quick Decline Syndrome". Essential oils (EOs) are an important source of bio-active volatile compounds that could interfere with basic metabolic, biochemical, physiological, and behavioural functions of insects. Here, we report the electrophysiological and behavioural responses of adult P. spumarius towards some EOs and related plants. Electroantennographic tests demonstrated that the peripheral olfactory system of P. spumarius females and males perceives volatile organic compounds present in the EOs of Pelargonium graveolens, Cymbopogon nardus and Lavandula officinalis in a dose-dependent manner. In behavioral bioassays, evaluating the adult responses towards EOs and related plants, both at close (Y-tube) and long range (wind tunnel), males and females responded differently to the same odorant. Using EOs, a clear attraction was noted only for males towards lavender EO. Conversely, plants elicited responses that varied upon the plant species, testing device and adult sex. Both lavender and geranium repelled females at any distance range. On the contrary, males were attracted by geranium and repelled by citronella. Finally, at close distance, lavender and citronella were repellent for females and males, respectively. Our results contribute to the development of innovative tools and approaches, alternative to the use of synthetic pesticides, for the sustainable control of P. spumarius aiming to contrasting the expansion of X. fastidiosa.
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http://dx.doi.org/10.1038/s41598-020-59835-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7033279PMC
February 2020

Chlamyphilone, a Novel Metabolite with Insecticidal Activity.

Molecules 2019 Feb 19;24(4). Epub 2019 Feb 19.

Dipartimento di Agraria, Università degli Studi di Napoli Federico II, 80055 Portici (NA), Italy.

Metabolites from a collection of selected fungal isolates have been screened for insecticidal activity against the aphid . Crude organic extracts of culture filtrates from six fungal isolates (, , , , and ) caused mortality of aphids within 72 h after treatment. In this work, bioassay-guided fractionation has been used to characterize the main bioactive metabolites accumulated in fungal extracts. Leucinostatins A, B and D represent the bioactive compounds produced by From and extracts, griseofulvin and beauvericin have been isolated, respectively; 3--Methylfunicone and a mixture of destruxins have been found in the active fractions of and , respectively. A novel azaphilone compound, we named chlamyphilone, with significant insecticidal activity, has been isolated from the culture filtrate of . Its structure has been determined using extensive spectroscopic methods and chemical derivatization.
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http://dx.doi.org/10.3390/molecules24040750DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6412625PMC
February 2019

Fibre-enriched buckwheat pasta modifies blood glucose response compared to corn pasta in individuals with type 1 diabetes and celiac disease: Acute randomized controlled trial.

Diabetes Res Clin Pract 2019 Mar 16;149:156-162. Epub 2019 Feb 16.

Department of Clinical Medicine and Surgery, Federico II University, Naples, Italy. Electronic address:

Aim: People with type 1 diabetes and celiac disease (T1D&CD) have high blood glucose variability. Processed gluten-free foods have shown to induce a worse metabolic profile whereas naturally gluten-free foods may represent healthier options. On the other hand, dietary fibre has shown to reduce postprandial glycemic excursions in individuals with diabetes. Thus, we evaluated the acute effect of fibre-enriched buckwheat (FBP) and corn pasta (CP) on postprandial blood glucose response (PP-BGR).

Methods: Ten adult patients with T1D&CD consumed two meals with the same amount of carbohydrate while differing only for pasta type (FBP or CP) preceded by the same insulin bolus. Participants utilized continuous glucose monitoring (CGM) and data over 6 h after meal were analyzed.

Results: PP-BGR differed between the two meals, being significantly lower in the first period (0-3 h) after the CP than the FBP meal (iAUC: -38 ± 158 vs. 305 ± 209 mmol/L · 180 min, p = 0.040), whereas significantly higher in the second period (3-6 h) after the CP than the FBP meal (iAUC: 432 ± 153 vs. 308 ± 252 mmol/L · 180 min, p = 0.030). Overall, a less variable postprandial profile was observed after FBP than CP consumption.

Conclusions: In individuals with T1D&CD, the acute consumption of FBP induces significant differences in PP-BGR compared with CP that may be clinically relevant.
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http://dx.doi.org/10.1016/j.diabres.2019.02.013DOI Listing
March 2019