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...

Total flavonoids contents and antibacterial activity of the extracts from the aerial parts of two Labiateae species, Nepeta menthoides Boiss. & Buhse and Thymus trautvetteri Klokov & Desj.-Shost. were determined. Quantitative determination of flavonoid contents was calculated in terms of quercetin equivalent in various extracts (50% methanol, chloroform and distilled water) by AlCl3 colorimetri...

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.