A reference extractive, containing multiple active known compounds, has been considered to be an alternative to individual reference standards. However, in the Chinese Pharmacopoeia (ChP) the great majority of reference extractives have been primarily used for qualitative identification by thin-layer chromatography (TLC) and few studies on the applicability of reference extractives for quantita...

MYB comprises a large family of transcription factors that play significant roles in plant development and stress response in plants. However, knowledge concerning the functions of MYBs and the target genes remains poorly understood. Here, we report the identification and functional characterization of a novel stress-responsive MYB gene from Pyrus betulaefolia. The MYB gene, designated as PbrMY...

Among the Rosaceae species, the gametophytic self-incompatibility (GSI) is controlled by a single multi-allelic S locus, which is composed of the pistil-S and pollen-S genes. The pistil-S gene encodes a polymorphic ribonuclease (S-RNase), which is essential for identifying self-pollen. However, the S-RNase system has not been fully characterized. In this study, the self-S-RNase inhibited the Ca...

Cultured pear (Pyrus communis 1. cv Passe Crassane) cells were subjected to temperatures of 39,42, and 45°C. Heat-shock protein (hsp) synthesis was greater at 39'C than at temperatures above 40'C and continued for up to 8 h. Both cellular uptake of radiolabeled methionine and total protein synthesis were progressively lower as the temperature was increased. Polysome levels decreased immediately...

With regard to the importance of antioxidants in foods, cosmetics and pharmaceutics, there are several studies on natural resources for finding rich sources of antioxidants and their role in protecting the body against oxidative stress injuries. The purpose of this study was to investigate the antioxidant stability of arbutin and the Pyrus boissieriana buhse Leaf extract and their effects on li...

Ribosome-inactivating proteins (RIPs) are widespread among higher plants of different taxonomic orders. In this study, we report on the RIP sequences found in the genome/transcriptome of several important Rosaceae species, including many economically important edible fruits such as apple, pear, peach, apricot, and strawberry. All RIP domains from Rosaceae share high sequence similarity with con...

Pear (Pyrus pyrifolia L.) has an S-RNase-based gametophytic self-incompatibility (SI) mechanism, and S-RNase has also been implicated in the rejection of self-pollen and genetically identical pollen. However, RNA degradation might be only the beginning of the SI response, not the end. Recent in vitro studies suggest that S-RNase triggers mitochondrial alteration and DNA degradation in the incom...

Please also refer to the excellent obituaries written by Miriam Poirier in Carcinogenesis and by Allan Conney in Cancer Research.

A loss and recovery of polysomes coincident with the temperature-dependent interruption and resumption of pear fruit (Pyrus communis, L.) senescence establishes a close correlation between the presence of protein-synthesizing machinery and the progression of senescence and ripening.

This report concerns a case with unusual lesions consisting of massive destruction of myelinated fibres in a thin marginal layer at the surface of the spinal cord, brain-stem, optic nerve and tract, without involvement of the superficial portions of grey matter. The lesions showed a striking similarity to those produced by barbotage (aspiration and reinjection of cerebrospinal fluid) in experim...