Plants requiring an insect pollinator often produce nectar as a reward for the pollinator's visitations. This rich secretion needs mechanisms to inhibit microbial growth. In Nicotiana spp. nectar, anti-microbial activity is due to the production of hydrogen peroxide. In a close relative, Petunia hybrida, limited production of hydrogen peroxide was found; yet petunia nectar still has anti-bacter...

The differences between stylar protein of the Japanese pear (Pyrus pyrifolia (Burm.f.)) cultivars ‘Kosui’ (SS) and ‘Kikusui’ (SS) were compared by two-dimensional difference gel electrophoresis (2-D DIGE), and were labelled and visualized with different fluorescent dyes (IC3-OSu, IC5-OSu) on a single 2-D gel. The individual different expressed proteins spots were subjected to identification. Th...

A 45-kDa ribonuclease (RNase) was purified from dried fruiting bodies of the wild mushroom Amanita hemibapha. It was adsorbed on DEAE-cellulose, S-sepharose, and finally purified on Superdex 75. The RNase exhibited maximal RNase activity at pH 5 and in a temperature range between 60-70°C. It demonstrated no ribonucleolytic activity toward four polyhomoribonucleotides. The amino acid sequence an...

S-RNase-based gametophytic self-incompatibility evolved once before the split of the Asteridae and Rosidae. In Prunus (tribe Amygdaloideae of Rosaceae), the self-incompatibility S-pollen is a single F-box gene that presents the expected evolutionary signatures. In Malus and Pyrus (subtribe Pyrinae of Rosaceae), however, clusters of F-box genes (called SFBBs) have been described that are express...

Self-incompatibility has been studied by using controlled pollination, pollen tube growth and PCR methods in the Iranian almond ‘Mamaei.’. Pollen tube growth and fruit set following self and cross-pollination treatments were evaluated. The percentage of initial and final fruit set was determined for each treatment at 30 and 60 days after controlled pollination. Pollen germination and pollen ...

A survey of Solanum chacoense plants expressing an authentic S(11)-RNase transgene identified a line with partial compatibility to S(11) pollen. By comparing fruit set to the S-RNase levels determined immunologically in single styles, the minimum level of S(11)-RNase required for full rejection of S(11) pollen was estimated to be 18 ng per style. The S(11)-RNase threshold levels are thus consid...