Genome-wide analysis of NDR1/HIN1-like genes in pepper(Capsicum annuum L.)and functional characterization of CaNHL4 under biotic and abiotic stresses

Plant NDR1/HIN1-like(NHL)genes play an important role in triggering plant defenses in response to biotic stresses.In this study,we performed a genome-wide identification of the NHL genes in pepper(Capsicum annuum L.)and characterized the functional roles of these CaNHL genes in response to abiotic stresses and infection by different pathogens.Phylogenetic analysis revealed that CaNHLs can be classified into five distinct subgroups,with each group containing generic and specific motifs.Regulatory element analysis showed that the majority of the promoter regions of the identified CaNHLs contain jasmonic acid(JA)-responsive and salicylic acid(SA)-responsive elements,and transcriptomic analysis revealed that CaNHL genes are expressed in all the examined tissues of pepper.The CaNHL1,CaNHL4,CaNHL6,CaNHL10,CaNHL11,and CaNHL12 genes were significantly upregulated under abiotic stress as well as in response to different pathogens,such as TMV,Phytophthora capsici and Pseudomonas syringae.In addition,we found that CaNHL4 localizes to the plasma membrane.CaNHL4-silenced pepper plants display significantly increased susceptibility to TMV,Phytophthora capsici and Pseudomonas syringae,exhibiting reduced expression of JA-related and SA-related genes and reduced ROS production.However,transient overexpression of CaNHL4 in pepper increases the expression of JArelated and SA-related genes,enhances the accumulation of ROS,and inhibits the infection of these three pathogens.Collectively,for the first time,we identified the NHL genes in pepper and demonstrated that CaNHL4 is involved in the production of ROS and that it also regulates the expression of JA-related and SA-related genes in response to different pathogens,suggesting that members of the CaNHL family play an essential role in the disease resistance of pepper.

Two-dimensional porous carbon derived from pollen with enlarged interlayer distance enhanced electrocatalytic oxidation of n-valeraldehyde to octane

Electrocatalytic n-valeraldehyde oxidation reaction was an inexpensive and eco-friendly method to control n-valeraldehyde contamination and produce high value-added octane.However,low-cost and readily available electrocatalysts with high current efficiency were urgently needed.Herein,two-dimensional porous carbon derived from pollen with enlarged interlayer distance was built by alkali activation method,applying in electrocatalytic n-valeraldehyde oxidation reaction.The enlarged interlayer distance was verified by X-ray diffraction(XRD)and high-angle annular dark-field scanning transmission electron microscope(HAADF-STEM).Electrocatalytic experiments consequences showed activated biomass derived carbon possessed a higher electrocatalytic activity and octane selectivity than unactivated catalyst.Systematic tests and in situ infrared experiments demonstrated that enlarged interlayer distance was positively correlated with specific surface area of catalysts,large specific surface area provided abundant absorption sites,facilitated the adsorption for n-valeraldehyde,and further promoted the transformation of n-valeraldehyde to octane.This work also provides a new avenue for creating high-performance electrocatalysts in terms of lattice engineering.