Enhanced resistance to bacterial and fungal pathogens by overexpression of a human cathelicidin antimicrobial peptide (hCAP18/LL-37) in Chinese cabbage

The human cathelicidin antimicrobial protein hCAP18, which includes the C-terminal peptide LL-37, is a multifunctional protein. As a possible approach to enhancing the resistance to plant disease, a DNA fragment coding for hCAP18/LL-37 was fused at the C-terminal end of the leader sequence of endopolygalacturonase-inhibiting protein under the control of the cauliflower mosaic virus 35S promoter region. The construct was then introduced into Brassica rapa. LL-37 expression was confirmed in transgenic plants by reverse transcription-polymerase chain reaction and western blot analysis. Transgenic plants exhibited varying levels of resistance to bacterial and fungal pathogens. The average size of disease lesions in the transgenic plants was reduced to less than half of that in wild-type plants. Our results suggest that the antimicrobial LL-37 peptide is involved in wide-spectrum resistance to bacterial and fungal pathogen infection

Angle-resolved and resonant photoemission spectroscopy study of the Fermi surface reconstruction in the charge density wave systems CeTe2 and PrTe2

The electronic structures of a charge density wave (CDW) system RTe2 (R=Ce,Pr) have been investigated by employing angle-resolved photoemission spectroscopy (ARPES) and the first-principles band structure method. The R 4f hybridization peak (4fncm-1) in the R 4f PES spectrum is located deeper in PrTe2 than in CeTe2 and R 4f spectral intensity near EF is much weaker in PrTe2 than in CeTe2, implying the importance of the hybridization between Ce 4f and Te(1) 5p electrons. For both CeTe2 and PrTe2, the metallic states crossing the Fermi level (EF) are observed below the CDW transition temperature, indicating the existence of the partially ungapped Fermi surfaces (FSs). The zigzag features having the fourfold rotational symmetry are observed near the X point in the FS of CeTe2, but not in the FS of PrTe2. The tight-binding model calculations show that the zigzag FS features in CeTe2 can be described as the CDW-induced FS reconstruction due to the 4×4 CDW supercell structure. The effect of the linear dichroism is observed in ARPES, suggesting that the EF-crossing states have mainly the in-plane orbital character. The photon-energy maps for the near-EF states exhibit the straight vertical dispersions for both CeTe2 and PrTe2, demonstrating the dominant two-dimensional character in RTe2 (R=Ce,Pr). © 2015 American Physical Society.

Majorana fermions in the Kitaev quantum spin system α-RuCl3

Geometrical constraints to the electronic degrees of freedom within condensed-matter systems often give rise to topological quantum states of matter such as fractional quantum Hall states, topological insulators, and Weyl semimetals. In magnetism, theoretical studies predict an entangled magnetic quantum state with topological ordering and fractionalized spin excitations, the quantum spin liquid. In particular, the so-called Kitaev spin model, consisting of a network of spins on a honeycomb lattice, is predicted to host Majorana fermions as its excitations. By means of a combination of specific heat measurements and inelastic neutron scattering experiments, we demonstrate the emergence of Majorana fermions in single crystals of α-RuCl 3, an experimental realization of the Kitaev spin lattice. The specific heat data unveils a two-stage release of magnetic entropy that is characteristic of localized and itinerant Majorana fermions. The neutron scattering results corroborate this picture by revealing quasielastic excitations at low energies around the Brillouin zone centre and an hour-glass-like magnetic continuum at high energies. Our results confirm the presence of Majorana fermions in the Kitaev quantum spin liquid and provide an opportunity to build a unified conceptual framework for investigating fractionalized excitations in condensed matter. © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.1