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A defence response can be induced by nonpathogenic Fusarium oxysporum CS-20 in several crops, but the molecular mechanism has not been clearly demonstrated. In the present study, we analysed the defence mechanism of a susceptible cucumber cultivar ( Cucumis sativus L. 9930) against a pathogen ( F. oxysporum f. sp. cucumerinum) through the root precolonization of CS-20. A challenge inoculation assay indicated that the disease severity index (DSI) was reduced, ranging from 18.83 to 61.67 in comparison with the pathogen control. Root colonization analysis indicated that CS-20 clearly did not appear to influence the growth of cucumber seedlings. Quantitative reverse-transcriptase polymerase chain reaction ( qRT-PCR) revealed that CS-20-mediated defence response was activated by PR3, LOX1 and PAL1 and the pathogen-mediated resistance response was regulated by PR1 and PR3. Moreover, both nonpathogenic and pathogenic F. oxysporum were able to upregulate NPR1 expression. In contrast to a pathogen, CS-20 can activate the Ca2+/CaM signal transduction pathway, and the gene expression of both CsCam7 and CsCam12 increased significantly. The gene expression analysis indicated that CS-20 strongly enhanced the expression of PR3, LOX1, PAL1, NPR1, CsCam7 and CsCam12 after inoculation. Overall, the defence response induced by CS-20 can be controlled by multiple genes in the cucumber plant. [ABSTRACT FROM AUTHOR]

Abstract: The Phytophthora capsici inflicts damage on numerous crop plants by secreting a series of pectinase including pectin methylesterase (PME). We identified a PME gene (pcpme6) from a genomic library of a highly virulent P. capsici strain SD33 which had an encoded a polypeptide of 348 amino acid residues with a predicted molecular mass of 38.18 kDa. We also confirmed that pcpme6 was increasingly expressed during symptom development following P. capsici infection of pepper leaves. The wild-type protein (PCPME6) ca. 50 kDa was obtained from pcpme6 expression, and PME activity trend in PCPME6-treated pepper leaves increased with symptom development. PCPME6 degraded leaf cell walls, resulting in the production of necrotic lesions. Mutation of Asp residues in active sites within pcpme6 affected PCPME6 activity and its virulence on pepper leaves. Results show that pcpme6 is a gene within the pme gene family that is important for pathogenesis of P. capsici on pepper. [Copyright &y& Elsevier]

In this work Cu 1.4 Mn 1.6 O 4 (CMO) spinel oxide is prepared and evaluated as a novel cobalt-free cathode for intermediate temperature solid oxide fuel cells (IT-SOFCs). Single phase CMO powder with cubic structure is identified using XRD. XPS results confirm that mixed Cu + /Cu 2+ and Mn 3+ /Mn 4+ couples exist in the CMO sample, and a maximum conductivity of 78 S cm −1 is achieved at 800 °C. Meanwhile, CMO oxide shows good thermal and chemical compatibility with a 10 mol% Sc 2 O 3 stabilized ZrO 2 (ScSZ) electrolyte material. Impedance spectroscopy measurements reveals that CMO exhibits a low polarization resistance of 0.143 Ω cm 2 at 800 °C. Furthermore, a Ni-ScSZ/ScSZ/CMO single cell demonstrates a maximum power density of 1076 mW cm −2 at 800 °C under H 2 (3% H 2 O) as the fuel and ambient air as the oxidant. These results indicate that Cu 1.4 Mn 1.6 O 4 is a superior and promising cathode material for IT-SOFCs. [ABSTRACT FROM AUTHOR]