Genetic mechanism, baseline sensitivity and risk of resistance to oxathiapiprolin in oomycetes.

Background: Oxathiapiprolin is a piperidinyl thiazole isoxazoline fungicide discovered by DuPont and commercialized by Corteva Agriscience. It acts by inhibiting a novel fungal target, an oxysterol binding protein (OSBP), and is intrinsically highly active against oomycetes including grape downy mildew (Plasmopara viticola) and potato late blight (Phytophthora infestans). Because the fungicide acts at a single site there is a need to determine the risk of resistance development.

Optimization of the HyPer sensor for robust real-time detection of hydrogen peroxide in the rice blast fungus.

Reactive oxygen species (ROS) production and breakdown have been studied in detail in plant-pathogenic fungi, including the rice blast fungus, Magnaporthe oryzae; however, the examination of the dynamic process of ROS production in real time has proven to be challenging. We resynthesized an existing ROS sensor, called HyPer, to exhibit optimized codon bias for fungi, specifically Neurospora crassa, and used a combination of microscopy and plate reader assays to determine whether this construct could detect changes in fungal ROS during the plant infection process. Using confocal microscopy, we were able to visualize fluctuating ROS levels during the formation of an appressorium on an artificial hydrophobic surface, as well as during infection on host leaves.

Discovery of oxathiapiprolin, a new oomycete fungicide that targets an oxysterol binding protein.

Oxathiapiprolin is the first member of a new class of piperidinyl thiazole isoxazoline fungicides with exceptional activity against plant diseases caused by oomycete pathogens. It acts via inhibition of a novel fungal target-an oxysterol binding protein-resulting in excellent preventative, curative and residual efficacy against key diseases of grapes, potatoes and vegetables. Oxathiapiprolin is being developed globally as DuPont™ Zorvec™ disease control with first registration and sales anticipated in 2015.

Inhibition of the alternative complement pathway preserves photoreceptors after retinal injury.

Degeneration of photoreceptors is a primary cause of vision loss worldwide, making the underlying mechanisms surrounding photoreceptor cell death critical to developing new treatment strategies. Retinal detachment, characterized by the separation of photoreceptors from the underlying retinal pigment epithelium, is a sight-threatening event that can happen in a number of retinal diseases. The detached photoreceptors undergo apoptosis and programmed necrosis.

Macrophage- and RIP3-dependent inflammasome activation exacerbates retinal detachment-induced photoreceptor cell death.

Detachment of photoreceptors from the retinal pigment epithelium is seen in various retinal disorders, resulting in photoreceptor death and subsequent vision loss. Cell death results in the release of endogenous molecules that activate molecular platforms containing caspase-1, termed inflammasomes. Inflammasome activation in retinal diseases has been reported in some cases to be protective and in others to be detrimental, causing neuronal cell death.