The eggplant AG91-25 recognizes the Type III-secreted effector RipAX2 to trigger resistance to bacterial wilt (Ralstonia solanacearum species complex).

To deploy durable plant resistance, we must understand its underlying molecular mechanisms. Type III effectors (T3Es) and their recognition play a central role in the interaction between bacterial pathogens and crops. We demonstrate that the Ralstonia solanacearum species complex (RSSC) T3E ripAX2 triggers specific resistance in eggplant AG91-25, which carries the major resistance locus EBWR9.

Genotyping by Sequencing Highlights a Polygenic Resistance to Ralstonia pseudosolanacearum in Eggplant (Solanum melongena L.).

Eggplant cultivation is limited by numerous diseases, including the devastating bacterial wilt (BW) caused by the species complex (RSSC). Within the RSSC, (including phylotypes I and III) causes severe damage to all solanaceous crops, including eggplant. Therefore, the creation of cultivars resistant to strains is a major goal for breeders.

Eggplant Resistance to the Species Complex Involves Both Broad-Spectrum and Strain-Specific Quantitative Trait Loci.

Bacterial wilt (BW) is a major disease of solanaceous crops caused by the species complex (RSSC). Strains are grouped into five phylotypes (I, IIA, IIB, III, and IV). Varietal resistance is the most sustainable strategy for managing BW.

A self-assembled three-dimensional cloak in the visible.

An invisibility cloak has been designed, realized and characterized. The cloak hides free-standing sub-wavelength three-dimensional objects at the short wavelength edge of the visible spectrum. By a bottom-up approach the cloak was self-assembled around the object.

A self-organized anisotropic liquid-crystal plasmonic metamaterial.

A composite material that leads to self organization of mesogen-coated gold nanospheres is synthesized and shows enhanced anisotropic optical properties due to synergistic effects of the mesogens intrinsic birefringence and its ability to drive the self-assembly process into highly anisotropic architectures with densely packed nanospheres. Such nanoengineered matter sustains a response beyond that achievable by its individual constituents, i.e.

Genetic mapping of a major dominant gene for resistance to Ralstonia solanacearum in eggplant.

Resistance of eggplant against Ralstonia solanacearum phylotype I strains was assessed in a F(6) population of recombinant inbred lines (RILs) derived from a intra-specific cross between S. melongena MM738 (susceptible) and AG91-25 (resistant). Resistance traits were determined as disease score, percentage of wilted plants, and stem-based bacterial colonization index, as assessed in greenhouse experiments conducted in Réunion Island, France.

A novel synthetic quantification standard including virus and internal report targets: application for the detection and quantification of emerging begomoviruses on tomato.

Background: Begomovirus is a genus of phytopathogenic single-stranded DNA viruses, transmitted by the whitefly Bemisia tabaci. This genus includes emerging and economically significant viruses such as those associated with Tomato Yellow Leaf Curl Disease, for which diagnostic tools are needed to prevent dispersion and new introductions. Five real-time PCRs with an internal tomato reporter gene were developed for accurate detection and quantification of monopartite begomoviruses, including two strains of the Tomato yellow leaf curl virus (TYLCV; Mld and IL strains), the Tomato leaf curl Comoros virus-like viruses (ToLCKMV-like viruses) and the two molecules of the bipartite Potato yellow mosaic virus.

Bacterial wilt resistance in tomato, pepper, and eggplant: genetic resources respond to diverse strains in the Ralstonia solanacearum species complex.

Bacterial wilt, caused by strains belonging to the Ralstonia solanacearum species complex, inflicts severe economic losses in many crops worldwide. Host resistance remains the most effective control strategy against this disease. However, wilt resistance is often overcome due to the considerable variation among pathogen strains.

Channel and wedge plasmon modes of metallic V-grooves with finite metal thickness.

We investigate numerically the effect of a finite metal film thickness on the propagation characteristics of the channel Plasmon polariton (CPP) and wedge plasmon polariton (WPP) modes, both in a symmetric and asymmetric environment. We observe that decreasing the metal thickness results in an improvement of the field localization near the groove tip and an increase of the losses for both types of mode. This behavior stems from the typical symmetric charge distribution of both modes across the metal film.

Evaluation of Maize Inbreds for Maize stripe virus and Maize mosaic virus Resistance: Disease Progress in Relation to Time and the Cumulative Number of Planthoppers.

ABSTRACT Five tropical maize lines were tested and compared with the susceptible control line B73 for resistance to Maize stripe virus (MStV) and Maize mosaic virus (MMV), both propagatively transmitted by the planthopper Peregrinus maidis (Homoptera: Delphacidae). Resistance to each virus was evaluated separately by artificial inoculations with planthoppers viruliferous for either one virus or the other. Disease incidence and symptom severity progression were quantified in relation to time and the cumulative number of planthoppers.

Coupling efficiency of light to surface plasmon polariton for single subwavelength holes in a gold film.

The excitation of surface plasmon polaritons (SPP) by focusing a laser beam on single subwavelength holes opened in a thin gold film is studied both experimentally and theoretically. By means of leakage radiation microscopy, quantitative measurements of the light-SPP coupling efficiency are performed for holes with different sizes and shapes. The system is studied theoretically by using a modal expansion method to calculate the fraction of the incident energy which is scattered by the hole into a surface plasmon.

Surface plasmon interferometry: measuring group velocity of surface plasmons.

Optical transmission spectroscopy on metal films with slit-groove pairs is conducted. Spectra of the light transmitted through the slit exhibit Fabry-Perot-type interference fringes due to surface plasmons propagating between the slit and the groove. The spectral dependence of the period of interference fringes is used to determine the group velocity of surface plasmons on flat gold and silver surfaces.

Dual-color fluorescence cross-correlation spectroscopy in a single nanoaperture : towards rapid multicomponent screening at high concentrations.

Single nanometric apertures in a metallic film are used to develop a simple and robust setup for dual-color fluorescence cross-correlation spectroscopy (FCCS) at high concentrations. If the nanoaperture concept has already proven to be useful for single-species analysis, its extension to the dual-color case brings new interesting specificities. The alignment and overlap of the two excitation beams are greatly simplified.

Diffusion analysis within single nanometric apertures reveals the ultrafine cell membrane organization.

We describe the development of a new methodology to probe the plasma membrane organization of living cells at the nanometric scale. Single nanometric apertures in a metallic film limit the observed membrane area below the optical diffraction barrier. The new approach performs fluorescence correlation spectroscopy with increasing aperture sizes and extracts information on the diffusion process from the whole set of data.

Field enhancement in single subwavelength apertures.

A peak of the detected fluorescence rate per molecule has recently been observed in experiments of fluorescence correlation spectroscopy carried out on subwavelength apertures in metallic screens, a phenomenon that appears at a diameter-to-wavelength ratio below the fundamental mode cutoff. Although the origin of the resonant transmission through a subwavelength aperture has been well explained in terms of excitation of plasmon surface modes on the aperture ridge, the origin of the maximum that occurs at a radius-to-wavelength ratio smaller than 1/4 was not clear. Using a rigorous electromagnetic theory of light diffraction in cylindrical geometry, we show that it is linked to the appearance of the fundamental mode propagating inside the aperture.

Identification of QTLs for Ralstonia solanacearum race 3-phylotype II resistance in tomato.

Resistance against a Ralstonia solanacearum race 3-phylotype II strain JT516 was assessed in a F(2:3) and a population of inbred lines (RIL), both derived from a cross between L. esculentum cv. Hawaii 7996 (partially resistant) and L.

Single-fluorophore diffusion in a lipid membrane over a subwavelength aperture.

We use submicrometer apertures milled in an aluminium film to study the diffusion dynamics of beta-Bodipy-FL-C(5)-HPC (Bodipy-PC) fluorophores in a lipid dioleoylphosphatidylcholine (DOPC) multilayer. The observation volume is limited by the aperture diameter, well below the optical wavelength. This spatial resolution improvement comes together with an enhancement of the detected fluorescence per molecule as compared to an open sample, with a significant increase up to 3.

Enhancement of single-molecule fluorescence detection in subwavelength apertures.

We report the experimental proof of molecular count rate enhancement (up to 6.5-fold) and lifetime reduction for single fluorescent molecules diffusing in subwavelength apertures milled in aluminum films. The observed enhancement dependence with the aperture diameter agrees qualitatively with numerical electromagnetic computations of the excitation power density into the aperture volume.

Single molecule fluorescence in rectangular nano-apertures.

Fluorescence Correlation Spectroscopy is used to investigate fluorescent molecules in solution diffusing in subwavelength rectangular apertures milled in Aluminium films. This rectangular shape allows to switch between a propagating and an evanescent excitation field within the aperture, leading to a significant tunability of the observation volume. Due to the vicinity of the metal surface, the fluorophore's molecular lifetime inside the aperture appears to be dramatically reduced whatever the excitation field is set to.

Genetic mapping of maize stripe disease resistance from the Mascarene source.

Maize stripe virus (MStV) is a potentially threatening virus disease of maize in the tropics. We mapped quantitative trait loci (QTLs) controlling resistance to MStV in a maize population of 157 F(2:3) families derived from the cross between two maize lines, Rev81 (tropical resistant) and B73 (temperate susceptible). Resistance was evaluated under artificial inoculations in replicated screenhouse trials across different seasons in Réunion Island, France.

Surface plasmon polaritons and their role in the enhanced transmission of light through periodic arrays of subwavelength holes in a metal film.

We present results of the transmitted, reflected, and absorbed power associated with the enhanced transmittance of light through a silver film pierced by a periodic array of subwavelength holes. Comparing experimentally acquired dispersion curves under different polarization conditions shows that the transmission features of the array are consistent with p-polarized resonant modes of the structure. By exploring the regime in which no propagating diffracted orders are allowed, we further show that the transmittance maxima are associated with both reflectance minima and absorption maxima.

Genetic mapping of maize streak virus resistance from the Mascarene source. II. Resistance in line CIRAD390 and stability across germplasm.

The streak disease has a major effect on maize in sub-Saharan Africa. Various genetic factors for resistance to the virus have been identified and mapped in several populations; these factors derive from different sources of resistance. We have focused on the Réunion island source and have recently identified several factors in the D211 line.