Stylar proteins of four Prunus species, P. avium, P. dulcis, P. mume, and P. salicina, were surveyed by 2D-PAGE combined with immunoblot and N-terminal amino acid sequence analyses to identify S-proteins associated with gametophytic SI in the Prunus. All four S-allelic products tested for P. dulcis could be identified in the highly basic zone of the gel. These S-proteins had Mr of about 28–30 kDa and reacted with the anti-S4-serum prepared from Japanese pear (Pyrus serotina). Two of six S-allelic products tested for P. avium could be also identified in the 2D-PAGE profiles, with roughly the same pI and Mr as those of S-proteins of P. dulcis. Putative S-proteins for P. mume and P. salicina were found in the same area of 2D-PAGE as the area where S-proteins of P. avium and P. dulcis were located. N-terminal amino acid sequence analysis of these proteins revealed that they were similar to S-RNases reported previously.
R. Tao, H. Yamane, H. Sassa, H. Mori, H. Murayama, T.M. Gradziel, A.M. Dandekar and A. Sugiura
Reut Niska, Martin Goldway and Doron Schneider
Loquat ( Eriobotrya japonica Lindl.) is a subtropical evergreen fruit tree of the family Rosaceae, subfamily Maloideae ( Lin et al., 1999 ), which carries the RNase-dependent gametophytic self-incompatibility fertilization system. This system is
Akiko Watari, Toshio Hanada, Hisayo Yamane, Tomoya Esumi, Ryutaro Tao, Hideaki Yaegaki, Masami Yamaguchi, Kenji Beppu and Ikuo Kataoka
SC conferred by the S e -haplotype is unclear. In the present study, we thoroughly characterized the pistil and pollen S determinants of the specificity of the gametophytic self-incompatibility (GSI) reaction, S-RNase and SFB , respectively
Doron Schneider, Raphael A. Stern and Martin Goldway
Apple (Malus domestica) has a gametophytic self-incompatibility (GSI) system. Consequently, fertilization is achieved by cross-pollination with a compatible pollinator. Compatibility is governed by a multiallelic S locus. Cultivars are fully compatible when both of their S-loci differ and are semi compatible when one locus is identical and the other differs. In a previous study we found that the fruit set and yield of the apple cultivar `Topred' was reduced when it was pollinated by a semi compatible cultivar. To examine if this occurrence is a general feature in apples grown under suboptimal conditions, three additional cultivars, `Golden Delicious', `Granny Smith' and `Royal Gala', were studied as pollen recipients of semi and fully compatible pollinators. Based on PCR analysis of the S-RNase allele, it was determined that the pollination rate of the semi compatible was significantly lower than that of the fully compatible pollinator in all cases. This was reflected by the lower fruit set and seed set of `Golden Delicious' and `Royal Gala', but not of `Granny Smith'. In hand pollination experiments, where pollen was in excess, no difference was found between the semi and fully compatible pollinators in all three cases. These results indicate that the low yield, conferred by semi compatible pollinators, is due to insufficient cross-pollination (and not to cultivar characteristics). Thus, low yields due to semi compatibility may be avoided by appropriate honeybee management that will increase pollination. Still, under suboptimal conditions, for growth and pollination, full compatibility is preferable.
Hisayo Yamane, Ryutaro Tao, Akira Sugiura, Nathanael R. Hauck and Amy F. Iezzoni
This report demonstrates the presence of S-ribonucleases (S-RNases), which are associated with gametophytic self-incompatibility (SI) in Prunus L., in styles of self-incompatible and self-compatible (SC) selections of tetraploid sour cherry (Prunus cerasus L.). Based on self-pollen tube growth in the styles of 13 sour cherry selections, seven selections were SC, while six selections were SI. In the SI selections, the swelling of pollen tube tips, which is typical of SI pollen tube growth in gametophytic SI, was observed. Stylar extracts of these selections were evaluated by two-dimensional polyacrylamide gel electrophoresis. Glycoproteins which had molecular weights and isoelectric points similar to those of S-RNases in other Prunus sp. were detected in all selections tested. These proteins had immunological characteristics and N-terminal amino acid sequences consistent with the S-RNases in other Prunus sp. Two cDNAs encoding glycoproteins from `Erdi Botermo' were cloned. One of them had the same nucleotide sequence as that of S4-RNase of sweet cherry (Prunus avium L.), while the amino acid sequence from the other cDNA encoded a novel S-RNase (named Sa-RNase in this study). This novel RNase contained two active sites of T2/S type RNases and five regions conserved among other Prunus S-RNases. Genomic DNA blot analysis using cDNAs encoding S-RNases of sweet cherry as probes indicated that three or four S-RNase alleles are present in the genome of each selection regardless of SI. All of the selections tested seemed to have at least one S-allele that is also found in sweet cherry. Genetic control of SI/SC in tetraploid sour cherry is discussed based on the results obtained from restriction fragment length polymorphism analysis.
Ryutaro Tao, Hisayo Yamane, Akira Sugiura, Hideki Murayama, Hidenori Sassa and Hitoshi Mori
This report identifies S-RNases of sweet cherry (Prunus avium L.) and presents information about cDNA sequences encoding the S-RNases, which leads to the development of a molecular typing system for S-alleles in this fruit tree species. Stylar proteins of sweet cherry were surveyed by two dimensional polyaclylamide gel electrophoresis (2D-PAGE) to identify S-proteins associated with gametophytic self-incompatibility. Glycoprotein spots linked to S-alleles were found in a group of proteins which had Mr and pI similar to those of other rosaceous S-RNases. These glycoproteins were present at highest concentration in the upper segment of the mature style and shared immunological characteristics and N-terminal sequences with those of S-RNases of other plant species. cDNAs encoding these glycoproteins were cloned based on the N-terminal sequences. Genomic DNA and RNA blot analyses and deduced amino acid sequences indicated that the cDNAs encode S-RNases; thus the S-proteins identified by 2D-PAGE are S-RNases. Although S1 to S6-alleles of sweet cherry cultivars could be distinguished from each other with the genomic DNA blot analysis, a much simpler method of PCR-based typing system was developed for the six S-alleles based on the DNA sequence data obtained from the cDNAs encoding S-RNases.
Gal Sapir, Raphael A. Stern, Martin Goldway and Sharoni Shafir
, carries the S -RNase-mediated gametophytic self-incompatibility (GSI) system. This system was first identified in Solanaceae ( Anderson et al., 1986 ) and later in Rosaceae ( Sassa et al., 1992 ) and in Scrophulariaceae ( Xue et al., 1996
Rayane Barcelos Bisi, Rafael Pio, Daniela da Hora Farias, Guilherme Locatelli, Caio Morais de Alcântara Barbosa and Welison Andrade Pereira
subtropical regions ( Bettiol Neto et al., 2014 ). The fact that no pollinizer cultivars have been reported for these hybrids in subtropical regions might be the reason for their low effective fruiting. Most pear tree cultivars have gametophytic self-incompatibility
Javier Sanzol and Maria Herrero
adequate cropping ( Waite, 1894 ). Self-fertilization in pear is prevented by a gametophytic self-incompatibility system ( de Nettancourt, 2001 ) and pear cultivars are generally considered self-incompatible ( Crane and Lewis, 1942 ; Sanzol and Herrero
Yiran Li, Asuka Uchida, Akiha Abe, Akihiro Yamamoto, Tomonari Hirano and Hisato Kunitake
pollen Physiol. Veg. 22 323 331 Tao, R. Iezzoni, A.F. 2010 The S-RNase-based gametophytic self-incompatibility system in Prunus exhibits distinct genetic and molecular features Sci. Hort. 124 423 433 Uchida, A. 2012 Fundamental studies on self