ISHS Acta Horticulturae 636: XXVI International Horticultural Congress: Key Processes in the Growth and Cropping of Deciduous Fruit and Nut Trees
SELF-INCOMPATIBILITY IN JAPANESE PEARS: PECULIAR INHIBITORY ACTION OF S-RNASE ON SELF POLLEN-TUBE GROWTH IN VITRO |
| Authors: | S. Hiratsuka, A. Hirano, Y. Kawai, S.-L. Zhang |
| Keywords: | Pyrus pyrifolia, S-allele, RNase T1, RNase T2, RNase A |
| Abstract:
In Japanese pears (Pyrus pyrifolia Nakai), purified S-RNase (RNase associated with the self-incompatibility allele) from the styles can cause selective inhibition on the growth of self pollen-tubes in vitro, and its RNase activity is essential for the inhibitory action. However, stylar proteins of the pear (proteins removed from S-RNase by cation exchange chromatography), which possessed three times higher RNase activity than S-RNase, did not show any inhibitory action. When the biological function of several RNases, S-RNase, RNase T1, RNase T2 and RNase A, was compared in vitro, S-RNase against the self pollen showed the strongest inhibition, followed by RNase T1, RNase T2 and RNase A. S-RNase action on cross pollen was the weakest. These results suggest that S-RNase and/or the pollen-tube recognize their mate in vitro and degrade RNAs in the tube, resulting in the cessation of pollen-tube elongation. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
