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Summary: Plants have evolved a sophisticated immunity system for specific detection of pathogens and rapid induction of measured defences. Over‐ or constitutive activation of defences would negatively affect plant growth and development. Hence, the plant immune system is under tight positive and negative regulation. MAP kinase phosphatase1 (MKP1) has been identified as a negative regulator of plant immunity in model plant Arabidopsis. However, the molecular mechanisms by which MKP1 regulates immune signalling in wheat (Triticum aestivum) are poorly understood. In this study, we investigated the role of TaMKP1 in wheat defence against two devastating fungal pathogens and determined its subcellular localization. We demonstrated that knock‐down of TaMKP1 by CRISPR/Cas9 in wheat resulted in enhanced resistance to rust caused by Puccinia striiformis f. sp. tritici (Pst) and powdery mildew caused by Blumeria graminis f. sp. tritici (Bgt), indicating that TaMKP1 negatively regulates disease resistance in wheat. Unexpectedly, while Tamkp1 mutant plants showed increased resistance to the two tested fungal pathogens they also had higher yield compared with wild‐type control plants without infection. Our results suggested that TaMKP1 interacts directly with dephosphorylated and activated TaMPK3/4/6, and TaMPK4 interacts directly with TaPAL. Taken together, we demonstrated TaMKP1 exert negative modulating roles in the activation of TaMPK3/4/6, which are required for MAPK‐mediated defence signalling. This facilitates our understanding of the important roles of MAP kinase phosphatases and MAPK cascades in plant immunity and production, and provides germplasm resources for breeding for high resistance and high yield. [ABSTRACT FROM AUTHOR]

The difference in floatability between smithsonite and dolomite is small m the system with dodecyllamine as collector, and it Is difficult to separate by flotaiion. The effects of sodium tripolyphosphate,sodium pyrophosphate and sodium hmetaphosphate on the f1otation of smithsonite and dolomite were studied by single mineral f1otation experiment. The resuits show that when the dosage of soduum tripolyphosphate ss 30 mg/L,it has a strong nnhibitory effect on dolomite and a weaker inhibitory effect on smithsonite, achieving selective inhibition of dolomite. The actual ore test resuits show that using 600 g/t sodium tripolyphosphate as a dolomite inhibitor, znc concentrate with znc grade of 36. 49% and recovery of 75. 49% can be obtained by flotation separation, and the effective separation of smithsonite and dolomite can be reaiized. The inhibition mechanism of sodium tripolyphosphate on dolomite was dsscussed by Zeta potential test and adsorption capacity tes. The resuits show that sodium tripolyphosphate can signiiicanlly affect the adsorption of the collector dodecyllamine on the surface of dolomite,but has iittie effect on the adsorption of smithsonite, which increases the adsorption difference of the collector on the surface of smithsonite and dolomite,resuiting n the difference in the f1oatability between smithsonite and dolomite. [ABSTRACT FROM AUTHOR]

Powdery mildew fungi are obligate biotrophic pathogens that only invade plant epidermal cells. There are two epidermal surfaces in every plant leaf: the adaxial (upper) side and the abaxial (lower) side. While both leaf surfaces can be susceptible to adapted powdery mildew fungi in many plant species, there have been observations of leaf abaxial immunity in some plant species including Arabidopsis. The genetic basis of such leaf abaxial immunity remains unknown. In this study, we tested a series of Arabidopsis mutants defective in one or more known defense pathways with the adapted powdery mildew isolate Golovinomyces cichoracearum UCSC1. We found that leaf abaxial immunity was significantly compromised in mutants impaired for both the EDS1/PAD4- and PEN2/PEN3-dependent defenses. Consistently, expression of EDS1–yellow fluorescent protein and PEN2–green fluorescent protein fusions from their respective native promoters in the respective eds1-2 and pen2-1 mutant backgrounds was higher in the abaxial epidermal cells than in the adaxial epidermal cells. Altogether, our results indicate that leaf abaxial immunity against powdery mildew in Arabidopsis is at least partially due to enhanced EDS1/PAD4- and PEN2/PEN3-dependent defenses. Such transcriptionally pre-programmed defense mechanisms may underlie leaf abaxial immunity in other plant species such as hemp and may be exploited for engineering adaxial immunity against powdery mildew fungi in crop plants. [ABSTRACT FROM AUTHOR]