Searching for plant NLR immune receptors conferring resistance to potyviruses

To fight against invasion by pathogens,plants have evolved an elaborate innate immune system,of which the nucleotide-binding domain leucine-rich repeat-containing receptor(NLR)acts as the sensor and immune executor.Potyviruses,comprising one of the largest genera of plant viruses,cause severe crop yield losses worldwide.Inherited crop resistance to potyviruses can be used in breeding and plant transgenesis to control disease development.This review summarizes achievements in mapping and cloning NLR genes conferring dominant resistance against potyvirus in the families Fabaceae,Solanaceae,Brassicaceae,and Cucurbitaceae.It compares mechanisms of potyviral protein recognition and downstream signaling employed by NLRs and discusses strategies for exploiting NLRs to better control diseases caused by potyviruses.

Guanine-regulated proton transfer enhances CO_(2)-to-CH_(4) selectivity over copper electrode

Electrocatalytic CO_(2) reduction has attracted growing attention as a promising route to realize artificial carbon recycling.Proton transfer plays an essential role in CO_(2) reduction and dramatically impacts product distribution.However,the precise control of proton transfer during CO_(2) reduction remains challenging.In this study,we present a well-controlled proton transfer through the modification of several purines with similar molecular structures,and reveal a direct correlation between surface proton transfer capability and CO_(2) reduction selectivity over Cu electrode.With a moderate proton transfer capability,the guanine modification can remarkably boost CH_(4) production and suppress C2 products formation.In-situ ATR-SEIRAS suggests a weakened^(*)CO intermediate adsorption and a relatively low local pH environment after the guanine modification,which facilitates the^(*)CO protonation and detachment for CH_(4) generation.

The soybean GmPUB21-interacting protein GmDi19-5 responds to drought and salinity stresses via an ABA-dependent pathway

Drought-induced protein 19(Di19) is a Cys2/His2 zinc-finger protein that functions in plant growth and development and in tolerance to abiotic stresses.Gm PUB21,an E3 ubiquitin ligase,negatively regulates drought and salinity response in soybean.We identified potential interaction target proteins of Gm PUB21by yeast two-hybrid c DNA library screening,Gm Di19-5 as a candidate.Bimolecular fluorescence complementation and glutathionine-S-transferase pull-down assays confirmed the interaction between Gm Di19-5 and Gm PUB21.Gm Di19-5 was induced by Na Cl,drought,and abscisic acid(ABA) treatments.Gm Di19-5 was expressed in the cytoplasm and nucleus.Gm Di19-5 overexpression conferred hypersensitivity to drought and high salinity,whereas Gm Di19-5 silencing increased drought and salinity tolerance.Transcripts of ABA-and stress response-associated genes including Gm RAB18 and Gm DREB2A were downregulated in Gm Di19-5-overexpressing plants under drought and salinity stresses.ABA decreased the protein level of Gm Di19-5 in vivo,whereas Gm PUB21 increased the decrease of Gm Di19-5 after exogenous ABA application.The accumulation of Gm PUB21 was also inhibited by Gm Di19-5.We conclude that Gm PUB21 and Gm Di19-5 collaborate to regulate drought and salinity tolerance via an ABA-dependent pathway.

A cell wall-localized NLR confers resistance to Soybean mosaic virus by recognizing viral-encoded cylindrical inclusion protein.

Soybean mosaic virus (SMV) causes severe yield losses and seed quality reduction in soybean (Glycine max) production worldwide. Rsc4 from cultivar Dabaima is a dominant genetic locus for SMV resistance, and its mapping interval contains three Nucleotide-binding domain Leucine-rich Repeat containing (NLR) candidates (Rsc4-1, Rsc4-2, and Rsc4-3). The NLR-type resistant proteins were considered as important intracellular pathogen sensors in the previous studies. In this research, based on transient expression assay in Nicotiana benthamiana leaves, we found that the longest transcript of Rsc4-3 is sufficient to induce resistance response to SMV;and CRISPR/Cas9-mediated Rsc4-3 knockout in resistant cultivar Dabaima compromised the resistance. These indicate that Rsc4-3 confers resistance to SMV. Interestingly, Rsc4-3 encodes a cell wall localized NLR-type resistant protein (Rsc4-3). The internal polypeptide region responsible for apoplastic targeting of Rsc4-3 and the putative palmitoylation sites on the N-terminus are essential for the resistance response. Furthermore, we showed that viral-encoded cylindrical inclusion (CI) protein partially localizes to the cell wall and can interact with Rsc4-3. Virus-driven or transient expression of CI protein of avirulent SMV strains is enough to induce resistance response in the presence of Rsc4-3, suggesting that CI is the avirulent gene for Rsc4-3 mediated resistance. Our work exhibited a case of NLR recognizing virus in the apoplast and provided a simple and effective method for identifying resistant genes against SMV infection.

R_(SC3)K of soybean cv. Kefeng No.1 confers resistance to soybean mosaic virus by interacting with the viral protein P3

Soybean mosaic virus(SMV) is one of the most devastating viral pathogens of soybean(Glycine max(L.) Merr). In total, 22 Chinese SMV strains(SC1–SC22) have been classified based on the responses of 10 soybean cultivars to these pathogens. However, although several SMVresistance loci in soybean have been identified, no gene conferring SMV resistance in the resistant soybean cultivar(cv.) Kefeng No.1 has been cloned and verified. Here, using F_(2)-derived F_(3)(F_(2:3)) and recombinant inbred line(RIL) populations from a cross between Kefeng No.1 and susceptible soybean cv. Nannong 1138-2, we localized the gene in Kefeng No.1 that mediated resistance to SMV-SC3 strain to a 90-kb interval on chromosome 2. To study the functions of candidate genes in this interval, we performed Bean pod mottle virus(BPMV)-induced gene silencing(VIGS). We identified a recombinant gene(which we named R_(SC3)K) harboring an internal deletion of a genomic DNA fragment partially flanking the LOC100526921 and LOC100812666 reference genes as the SMV-SC3 resistance gene.By shuffling genes between infectious SMV DNA clones based on the avirulent isolate SC3 and virulent isolate 1129, we determined that the viral protein P3 is the avirulence determinant mediating SMV-SC3 resistance on Kefeng No.1. P3 interacts with RNase proteins encoded by R_(SC3)K, LOC100526921, and LOC100812666. The recombinant R_(SC3)K conveys much higher anti-SMV activity than LOC100526921 and LOC100812666, although those two genes also encode proteins that inhibit SMV accumulation, as revealed by gene silencing in a susceptible cultivar and by overexpression in Nicotiana benthamiana. These findings demonstrate that R_(SC3)K mediates the resistance of Kefeng No.1 to SMV-SC3 and that SMV resistance of soybean is determined by the antiviral activity of RNase proteins.

Scaling up of cluster beam deposition technology for catalysis application

Many research works have demonstrated that the combination of atomically precise cluster deposition and theoretical calculations is able to address fundamental aspects of size-effects,cluster-support interactions,and reaction mechanisms of cluster materials.Although the wet chemistry method has been widely used to synthesize nanoparticles,the gas-phase synthesis and size-selected strategy was the only method to prepare supported metal clusters with precise numbers of atoms for a long time.However,the low throughput of the physical synthesis method has severely constrained its wider adoption for catalysis applications.In this review,we introduce the latest progress on three types of cluster source which have the most promising potential for scale-up,including sputtering gas aggregation source,pulsed microplasma cluster source,and matrix assembly cluster source.While the sputtering gas aggregation source is leading ahead with a production rate of~20 mg·h^(-1),the pulsed microplasma source has the smallest physical dimensions which makes it possible to compact multiple such devices into a small volume for multiplied production rate.The matrix assembly source has the shortest development history,but already show an impressive deposition rate of~10 mg·h^(-1).At the end of the review,the possible routes for further throughput scale-up are envisaged.