Identification of Sesquiterpenes in Wild Tomato Accessions with Activities Against the Potato Aphid and Their Tissue-Specific Engineering in Cultivated Tomato

The potato aphid (Macrosiphum euphorbiae Thomas) poses a serious problem in the commercial production of horticultural crops including tomato, since it causes damage by stylet feeding and the transmission of viruses for which it serves as the vector. Application of conventional pesticides being the fundamental tactic in the control of the aphid is increasingly considered insufficient and problematic due to emerging pest resistances and biosafety issues, highlighting the continuing need to develop new efficient and sustainable approaches. Alternatively, glandular trichomes of plants are well-known epidermal hairy tissues producing various secondary metabolites that involve in plant-insect interactions, while the terpene compounds produced from type VI glandular trichomes were frequently referred to as antixenotic or antibiotic resistant against both piercing-sucking and chewing-biting herbivores. Recent studies of terpene production in glandular trichomes of tomato, found on leaves and stems, demonstrated significant differences between cultivated (Solanum lycopersicum L.) and wild tomatoes (Solanum habrochaites S.Knapp & D.M.Spooner), as well as quantitative and qualitative variation of sesquiterpenes among the wild tomato accessions. Thus, the current research aimed to explore (1) if certain sesquiterpene chemotypes from the wild accessions support resistance against the potato aphid by affecting its pre- and postlanding behaviors during their interaction, and (2) would the resistance in cultivated tomato be improved if defensive sesquiterpenes were produced in a different tissue along the aphid stylet pathway by metabolic engineering. To determine the effects of glandular trichome derived sesquiterpenes produced from wild tomato, five chemotypes (I-V) from a collection of S. habrochaites accessions were re-confirmed by gas chromatography-mass spectrometry (GC-MS). The performance (longevity and fecundity) of wingless aphids on tomato accessions, their feeding behaviors on an artificial diet, and the choice behaviors of winged aphids in an open Y-track olfactometer were analyzed. The results suggested that chemotype IV and V accessions which respectively produce mixtures of caryophyllene/α-humulene and santalene/bergamotene significantly reduced aphid longevity and fecundity in clip-cages while they were significantly repellent to winged aphids in the olfactometer. The trichome extracts from the two groups significantly affected aphid survivorship, gel saliva investment, and honeydew production in artificial diets, and significantly reduced the attraction of winged aphids to cultivated tomato. The same effects on feeding and choice behaviors were also observed by using pure caryophyllene/α-humulene as well as the trichome extract from one introgression line LA3935 which has santalene/bergamotene isomers predominantly produced in glandular trichomes. Cultivated tomato lines generally produce a large quantity of TPS20-derived monoterpenes and low quantities of TPS9-derived δ-elemene and TPS12-derived sesquiterpenes. To explain the susceptibility of cultivated tomato plants against the potato aphid, the performance parameters (longevity and fecundity) of wingless aphids were analyzed on four tomato lines that quantitatively differ in their terpene production, i.e., two cultivated tomato lines (Alisa Craig and Castlemart) with normal terpene production and their trichome mutants (hairless and odorless-2) producing respectively lesser amounts of sesquiterpenes and only tiny amounts of all terpene compounds. A principal component analysis (PCA) indicated that the performance parameters were negatively correlated with the production of the TPS12-derived sesquiterpenes, while no strong relationships were formed between the performance parameters and the production of TPS20-derived monoterpenes, which were further confirmed in artificial diets showing that the increasing concentration of TPS20-derived monoterpenes has little effects on aphid survivorship and production of gel saliva and honeydew. Additionally, a specific concentration of the TPS20-derived monoterpenes was significantly attractive to winged aphids in the olfactometer. Thus, the analyses explained the susceptibility of the cultivated tomato by revealing the contrasting roles of glandular trichome-derived monoterpenes and sesquiterpenes: while TPS12-derived sesquiterpenes contribute to host plant resistance against the potato aphid, TPS20-derived monoterpenes appear to be exploited as a cue for host plant orientation by the species. Since the two sesquiterpene mixtures produced in glandular trichomes of wild tomato accessions affect aphid feeding, two multicistronic expression constructs were developed to engineering their production in epidermal cells, as their epidermal-specific formation was presumed to reduce tissue penetration by aphids and subsequent performance. Both constructs contained sequences encoding a prenyl transferase (TPS), a respective terpene synthase (TPS), and an enhanced green fluorescent protein (GFP) as visible marker. All three coding sequences were linked by short nucleotide sequences encoding the foot-and-mouth disease virus 2A self-processing oligopeptide which allows their co-expression under the control of an epidermis-specific Arabidopsis CER5-promoter. Transient expression of both constructs by infiltrating odorless-2 leaves leads to the formation of the two sets of defensive sesquiterpenes, β-caryophyllene/α-humulene and santalene/bergamotene. The epidermis-specific transgene expression and terpene formation were verified by fluorescence microscopy and tissue fractionation with subsequent analysis of terpene profiles, respectively. In addition, the longevity and fecundity of the potato aphid feeding on infiltrated leaves were significantly reduced. This study overall identified two groups of sesquiterpenes in glandular trichomes of S. habrochaites accessions that support antixenotic resistance against the potato aphid by negatively affecting their performance and choice behavior. The defensive traits engineered in epidermal cells from the wild tomato also improved the resistance in susceptible tomato plants, suggesting a novel and sustainable non-pesticide strategy for managing the aphid species. Further studies need to be conducted to test whether the defensive sesquiterpenes are also antibiotic resistant with effects on aphid physiology and biology, and to produce the sesquiterpenes in other tissues, such as companion cells, along aphid stylet pathway, to evaluate tomato plant resistance to the potato aphid

The Factors Which Effect on the Diffusion of Information and Communication Technology in China

At this age, information and communication technology (ICT) are spread all over every corner of the world in a surprising speed, which deeply influences every aspect of our daily lives. Two factors can lead to diffusion of ICT innovation based on a case study, which was about internet cafe in China. The first factor is influence of new technology; the second factor is that stress or policies which come from society or governments

Robust and Real-time Deep Tracking Via Multi-Scale Domain Adaptation

Visual tracking is a fundamental problem in computer vision. Recently, some deep-learning-based tracking algorithms have been achieving record-breaking performances. However, due to the high complexity of deep learning, most deep trackers suffer from low tracking speed, and thus are impractical in many real-world applications. Some new deep trackers with smaller network structure achieve high efficiency while at the cost of significant decrease on precision. In this paper, we propose to transfer the feature for image classification to the visual tracking domain via convolutional channel reductions. The channel reduction could be simply viewed as an additional convolutional layer with the specific task. It not only extracts useful information for object tracking but also significantly increases the tracking speed. To better accommodate the useful feature of the target in different scales, the adaptation filters are designed with different sizes. The yielded visual tracker is real-time and also illustrates the state-of-the-art accuracies in the experiment involving two well-adopted benchmarks with more than 100 test videos.Comment: 6 page

High-dimensional quantum key distribution based on mutually partially unbiased bases

We propose a practical high-dimensional quantum key distribution protocol based on mutually partially unbiased bases utilizing transverse modes of light. In contrast to conventional protocols using mutually unbiased bases, our protocol uses Laguerre-Gaussian and Hermite-Gaussian modes of the same mode order as two mutually partially unbiased bases for encoding, which leads to a scheme free from mode-dependent diffraction in long-distance channels. Since only linear and passive optical elements are needed, our experimental implementation significantly simplifies qudit generation and state measurement. Since this protocol differs from conventional protocols using mutually unbiased bases, we provide a security analysis of our protocol

Surface-active hollow titanosilicate particles as a Pickering interfacial catalyst for liquid-phase alkene epoxidation reactions

Design of catalyst particles bearing excellent catalytic activity and suitable surface wettability is the key to the successful application of Pickering interfacial catalysis. In this study, the epoxidation of 1-hexene and cyclohexene with aqueous hydrogen peroxide over hollow TS-1 zeolite was studied as probe reactions to investigate the influence of catalyst surface wettability on catalytic activity. Hydrophobized hollow TS-1 particles (HTS-1) were fabricated via a post-synthesis desilication treatment with tetrapropylammonium hydroxide (TPAOH) and a post-synthesis silylation treatment with hexamethyldisiloxane (HMDSO). The successful preparation of HTS-1 particles was verified by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and Fourier-transform infrared spectroscopy (FTIR). X-ray diffraction patterns and UV-visible spectra confirmed that hydrophobic modification had no effect on the zeolite structure of HTS-1 particles. Stable Pickering emulsions of aqueous hydrogen peroxide in either 1-hexene or cyclohexene could be prepared using HTS-1 particles as emulsifier and confirmed by cryo-SEM images. The catalytic behaviour in the obtained Pickering emulsions revealed a parabolic distribution of turnover frequency (TOF) values with respect to the hydrophobization degree with 0.2-HMDSO/HTS-1 particles possessing the maximum value of 20.6 h-1 for 1-hexene epoxidation and 8.1 h-1 for cyclohexene epoxidation. In addition, these 0.2-HMDSO/HTS-1 particles showed good re-usability for more than five cycles

Lipopolysaccharide preconditioning enhances the efficacy of mesenchymal stem cells transplantation in a rat model of acute myocardial infarction

<p>Abstract</p> <p>Background</p> <p>Mesenchymal stem cells (MSCs)-based regenerative therapy is currently regarded as an alternative approach to salvage the acute myocardial infarcted hearts. However, the efficiency of MSCs transplantation is limited by lower survival rate of engrafted MSCs. In previous study, we found that 1.0 μg/ml Lipopolysaccharide (LPS) could protect MSCs against apoptosis induced by oxidative stress and meanwhile enhance the proliferation of MSCs. Therefore, in the present study, we firstly preconditioned MSCs with 1.0 μg/ml LPS, then transplanted MSCs into ischemic myocardium, and observed the survival and cardiac protective capacity of MSCs in a rat model of acute myocardial infarction. Furthermore, we tried to explore the underlying mechanisms and the role of Toll-like receptor-4 (TLR4) in the signal pathway of LPS-induced cardiac protection.</p> <p>Methods and results</p> <p>Acute myocardial infarction model was developed by left anterior descending coronary artery ligation. 60 rats were divided into 4 groups randomly and given an intramyocardial injection of one of the following treatments: 30 μl PBS (control group), 3 × 10⁶wild MSCs/30 μl (wMSCs group), 3 × 10⁶LPS-preconditioned wild MSCs/30 μl (LPS-wMSCs group), or 3 × 10⁶LPS-preconditioned TLR4 gene deleted MSCs/30 μl (LPS-tMSCs group). After 3 weeks, LPS-preconditioned wild MSCs transplantation ameliorated cardiac function and reduced fibrosis of infarcted myocardium. Vascular density was markedly increased in LPS-wMSCs group compared with other three groups. Survival rate of engrafted MSCs was elevated and apoptosis of myocardium was reduced in infarcted heart. Expression of vascular endothelial growth factor (VEGF) and phospho-Akt was increased in the infarcted myocardium after transplantation of LPS-preconditioned MSCs.</p> <p>Conclusion</p> <p>LPS preconditioning enhanced survival of engrafted MSCs, stimulated expression of VEGF and activated PI3K/Akt pathway. LPS preconditioning before MSCs transplantation resulted in superior therapeutic neovascularization and recovery of cardiac function. LPS preconditioning provided a novel strategy in maximizing biologic and functional properties of MSCs.</p

Rice Yield Estimation Using Parcel-Level Relative Spectral Variables From UAV-Based Hyperspectral Imagery

Time-series Vegetation Indices (VIs) are usually used for estimating grain yield. However, multi-temporal VIs may be affected by different background, illumination, and atmospheric conditions, so the absolute differences among time-series VIs may include the effects induced from external conditions in addition to vegetation changes, which will pose a negative effect on the accuracy of crop yield estimation. Therefore, in this study, the parcel-based relative vegetation index (ΔVI) and the parcel-based relative yield are proposed and further used to estimate rice yield. Hyperspectral images at key growth stages, including tillering stage, jointing stage, booting stage, heading stage, filling stage, and ripening stage, as well as rice yield, were obtained with Rikola hyperspectral imager mounted on Unmanned Aerial Vehicle (UAV) in 2017 growing season. Three types of parcel-level relative vegetation indices, including Relative Normalized Difference Vegetation Index (RNDVI), Relative Ratio Vegetation Index (RRVI), and Relative Difference Vegetation Index (RDVI) are created by using all possible two-band combinations of discrete channels from 500 to 900 nm. The optimal VI type and its band combinations at different growth stages are identified for rice yield estimation. Furthermore, the optimal combinations of different growth stages for yield estimation are determined by F-test and validated using leave-one-out cross validation (LOOCV) method. The comparison results show that, for the single-growth-stage model, RNDVI[880,712] at booting stage has the best correlation with rice yield with a R2-value of 0.75. For the multiple-growth-stage model, RNDVI[808,744] at jointing stage, RNDVI[880,712] at booting stage and RNDVI[808,744] at filling stage gain a higher R2-value of 0.83 with the mean absolute percentage error of estimated rice yield of 3%. The study demonstrates that the proposed method with parcel-level relative vegetation indices and relative yield can achieve higher yield estimation accuracy because it can make full use of the advantage that remote sensing can monitor relative changes accurately. The new method will further enrich the technology system for crop yield estimation based on remotely sensed data