Plant Genetics and Biotechnology in Biodiversity

Plant genetic resources for food and agriculture (PGRFA) have been collected and exchanged for centuries. The rapid development of novel tools for genetic and phenotypic analysis is changing the way we can uncover diversity and exploit its value in modern agriculture. The integration of novel analytical tools is crucial for translating research into much-needed, more efficient management and use of PGRFA. This Special Issue provides an overview of recent topics on plant genetics and biotechnology in biodiversity. The proposed reviews and research papers present current trends and examples of genetic resources’ description, conservation, management, and exploitation, highlighting that new approaches and methodogies can increase our understanding and efficient use of PGRFA to address the agricultural challenges that lie ahead

DNA markers as a tool for genetic traceability of primary product in agri-food chains

The agri-food components of the Made in Italy are well known all over the world, therefore they may significantly contribute to the Italian economy. However, also owing to a large number of cases of improper labelling, the Italian agro-food industry faces an ever-increasing competition. For this reason, there is a decline of consumers' confidence towards food production systems and safety controls. To prevent erroneous classification of products and to protect consumers from false instore information, it is important to develop and validate techniques that are able to detect mislabelling at any stage of the food-chain. This paper describes some examples of genetic traceability of primary products in some important plant food chains such as durum wheat, olive and tomato, based on DNA analysis both of raw material and of processed food (pasta, olive oil, and peeled tomato)

Initial experimental investigations on natural fibre reinforced honeycomb core panels

The main attention of the present work is on eco-friendly honeycomb cores for sandwich panels. They are manufactured by combining flax fibres with polyethylene matrix; the analyses involve both reinforced and un-reinforced cores. Some experimental tests have been planned and carried out in order to qualify the modal characteristics of this important class of panels. Tests results, herein discussed, report a great improvement of reinforced cores (continuous-unidirectional and short-random) compared to un-reinforced ones in mechanical properties. An improvement in damping value is achieved by filling the core with wool fibres resulting in minimal weight increase. A summary of the impact and acoustic tests results of preview tests are also reported in order to have a global view of the behaviour of these sandwich panels

In silico and in vitro approaches allow the identification of the Prosystemin molecular network

Tomato Prosystemin (ProSys), the precursor of Systemin, a small peptidic hormone, is produced at very low concentration in unchallenged plants, while its expression greatly increases in response to several different stressors triggering an array of defence responses. The molecular mechanisms that underpin such a wide array of defence barriers are not fully understood and are likely correlated with the intrinsically disordered (ID) structure of the protein. ID proteins interact with different protein partners forming complexes involved in the modulation of different biological mechanisms. Here we describe the ProSys-protein network that shed light on the molecular mechanisms underpinning ProSys associated defence responses. Three different approaches were used. In silico prediction resulted in 98 direct interactors, most clustering in phytohormone biosynthesis, transcription factors and signal transduction gene classes. The network shows the central role of ProSys during defence responses, that reflects its role as central hub. In vitro ProSys interactors, identified by Affinity Purification-Mass Spectrometry (AP-MS), revealed over three hundred protein partners, while Bimolecular Fluorescent Complementation (BiFC) experiments validated in vivo some interactors predicted in silico and in vitro. Our results demonstrate that ProSys interacts with several proteins and reveal new key molecular events in the ProSys-dependent defence response of tomato plant

De Novo Transcriptome Assembly of Cucurbita Pepo L. Leaf Tissue Infested by Aphis Gossypii

Zucchini (Cucurbita pepo L.), extensively cultivated in temperate areas, belongs to the Cucurbitaceae family and it is a species with great economic value. One major threat related to zucchini cultivation is the damage imposed by the cotton/melon aphid Aphis gossypii Glover (Homoptera: Aphididae). We performed RNA-sequencing on cultivar "San Pasquale" leaves, uninfested and infested by A. gossypii, that were collected at three time points (24, 48, and 96 h post infestation). Then, we combined all high-quality reads for de novo assembly of the transcriptome. This resource was primarily established to be used as a reference for gene expression studies in order to investigate the transcriptome reprogramming of zucchini plants following aphid infestation. In addition, raw reads will be valuable for new experiments based on the latest bioinformatic tools and analytical approaches. The assembled transcripts will serve as an important reference for sequence-based studies and for primer design. Both datasets can be used to support/improve the prediction of protein-coding genes in the zucchini genome, which has been recently released into the public domain

Transcriptome and metabolome reprogramming in tomato plants by Trichoderma harzianum strain T22 primes and enhances defence responses against aphids

Beneficial fungi in the genus Trichoderma are among the most widespread biocontrol agents of plant pathogens. Their role in triggering plant defences against pathogens has been intensely investigated, while, in contrast, very limited information is available on induced barriers active against insects. The growing experimental evidence on this latter topic looks promising, and paves the way towards the development of Trichoderma strains and/or consortia active against multiple targets. However, the predictability and reproducibility of the effects that these beneficial fungi is still somewhat limited by the lack of an in-depth understanding of the molecular mechanisms underlying the specificity of their interaction with different crop varieties, and on how the environmental factors modulate this interaction. To fill this research gap, here we studied the transcriptome changes in tomato plants (cultivar “Dwarf San Marzano”) induced by Trichoderma harzianum (strain T22) colonization and subsequent infestation by the aphid Macrosiphum euphorbiae. A wide transcriptome reprogramming, related to metabolic processes, regulation of gene expression and defence responses, was induced both by separate experimental treatments, which showed a synergistic interaction when concurrently applied. The most evident expression changes of defence genes were associated with the multitrophic interaction Trichoderma-tomato-aphid. Early and late genes involved in direct defence against insects wereinduced (i.e. peroxidase, GST, kinases and polyphenol oxidase, miraculin, chitinase), along with indirect defence genes, such as sesquiterpene synthase and geranylgeranyl phosphate synthase. Targeted and untargeted semi-polar metabolome analysis revealed a wide metabolome alteration showing an increased accumulation of isoprenoids in Trichodermatreated plants. The wide array of transcriptomic and metabolomics changes nicely fit with the higher mortality of aphids when feeding on Trichoderma treated plants,herein reported,and with the previously observed attractiveness of these latter towards the aphid parasitoid Aphidius ervi.Moreover, Trichoderma treated plants showed the over-expression of transcripts coding for several families of defence-related transcription factors (bZIP, MYB, NAC, AP2-ERF, WRKY), suggesting that the fungus contributes to the priming of plant responses against pest insects. Collectively, our data indicate that Trichoderma treatment of tomato plants induces transcriptomic and metabolomic changes, which underpin both direct and indirect defence responses

Evolution of the Population of Very Strong MgII Absorbers

We present a study of the evolution of several classes of MgII absorbers, and their corresponding FeII absorption, over a large fraction of cosmic history: 2.3 to 8.7 Gyrs from the Big Bang. Our sample consists of 87 strong (Wr(MgII)>0.3 A) MgII absorbers, with redshifts 0.2<z<2.5, measured in 81 quasar spectra obtained from the Very Large Telescope(VLT)/Ultraviolet and Visual Echelle Spectrograph(UVES) archives of high-resolution spectra (R \sim 45,000). No evolutionary trend in Wr(FeII)/Wr(MgII) is found for moderately strong MgII absorbers (0.3<Wr(MgII)<1.0 A). However, at lower z we find an absence of very strong MgII absorbers (those with Wr(MgII)>1 A) with small ratios of equivalent widths of FeII to MgII. At high z, very strong MgII absorbers with both small and large Wr(FeII)/Wr(MgII) values are present. We compare our findings to a sample of 100 weak MgII absorbers (Wr(MgII)<0.3 A) found in the same quasar spectra by Narayanan et al. (2007). The main effect driving the evolution of very strong MgII systems is the difference between the kinematic profiles at low and high redshifts. At high z, we observe that, among the very strong MgII absorbers, all of the systems with small ratios of Wr(FeII)/Wr(MgII) have relatively large velocity spreads, resulting in less saturated profiles. At low z, such kinematically spread systems are absent, and both FeII and MgII are saturated, leading to Wr(FeII)/Wr(MgII) values that are all close to 1. The high redshift, small Wr(FeII)/Wr(MgII) systems could correspond to sub-DLA systems, many of which have large velocity spreads and are possibly linked to superwinds in star forming galaxies. In addition to the change in saturation due to kinematic evolution, the smaller Wr(FeII)/Wr(MgII) values could be due to a lower abundance of Fe at high z, which would indicate relatively early stages of star formation in those environments.Comment: 20 pages, 14 figures (figure 1 is a set of 87 figures, which is available on the online version), accepted for publication in the MNRA

Sensitivity analysis of a double corrugated waveguide slow wave structure for a 151 - 161.5 GHz TWT

TWTs at D-band (141 – 174.5 GHz) are the most promising solution to provide high transmission power for enabling long range wireless links with high capacity at sub-THz frequency. A D-band TWT was designed in the 151-161.5 GHz frequency band with about 10 W output power. The double corrugated waveguide is adopted as slow wave structure (SWS) for the relatively easy fabrication and alignment in comparison to other SWSs typically used at sub-THz frequency. Due to the short wavelength at D-band, the fabrication requires high precision computerised numerically controlled (CNC) milling machining and tight tolerance control. The sensitivity analysis of performance as a function of the dimensions of a device is an important method to predict in advance how the performance of the device is affected by geometry variations, and also to ascertain the required level of fabrication accuracy to meet the specifications. The sensitivity analysis is also useful to define the best initial dimensions for further optimization. This paper discusses the sensitivity analysis applied to the double corrugated waveguide (DCW) to be used in a 151-161.5 GHz TWT. A broad range of parameters are considered demonstrating the importance of fabrication accuracy and the eventual correction options for a correct functioning. The impact of fillets in the DCW pillars is also evaluated to eventually ease the fabrication requirement