The RNase mechanism
| ← Previous revision | Revision as of 15:04, 9 December 2021 | ||
| Line 17: | Line 17: | ||
|
In this mechanism, pollen tube elongation is halted when it has proceeded approximately one third of the way through the [[carpel|style]].<ref name=”franklin-tong2003″>{{cite journal |doi=10.1098/rstb.2003.1287 |author1=Franklin-Tong, V. E. |author2=F. C. H. Franklin |name-list-style=amp |title=The different mechanisms of gametophytic self-incompatibility |journal=[[Philosophical Transactions of the Royal Society B]] |volume=358 |issue=1434 |pages=1025–32 |year=2003 |pmid=12831468 |pmc=1693207 }}</ref> The female component [[ribonuclease]], termed ”’S-RNase”'<ref name=”mcclure”>{{cite journal |doi=10.1038/342955a0 |author=McClure, B. A., V. Haring, , P. R. Ebert, M. A. Anderson, R. J. Simpson, F. Sakiyama, and A. E. Clarke |title=Style selfincompatibility gene products of ”Nicotiana alata” are ribonucleases |journal=Nature |volume=342 |issue=6252 |pages=955–7 |year=1989 |pmid=2594090 |bibcode=1989Natur.342..955M |s2cid=4321558 |doi-access=free }}</ref> probably causes degradation of the [[ribosome|ribosomal]] [[RNA]] (rRNA) inside the pollen tube, in the case of identical male and female S alleles, and consequently pollen tube elongation is arrested, and the pollen grain dies.<ref name=”franklin-tong2003″/>
|
In this mechanism, pollen tube elongation is halted when it has proceeded approximately one third of the way through the [[carpel|style]].<ref name=”franklin-tong2003″>{{cite journal |doi=10.1098/rstb.2003.1287 |author1=Franklin-Tong, V. E. |author2=F. C. H. Franklin |name-list-style=amp |title=The different mechanisms of gametophytic self-incompatibility |journal=[[Philosophical Transactions of the Royal Society B]] |volume=358 |issue=1434 |pages=1025–32 |year=2003 |pmid=12831468 |pmc=1693207 }}</ref> The female component [[ribonuclease]], termed ”’S-RNase”'<ref name=”mcclure”>{{cite journal |doi=10.1038/342955a0 |author=McClure, B. A., V. Haring, , P. R. Ebert, M. A. Anderson, R. J. Simpson, F. Sakiyama, and A. E. Clarke |title=Style selfincompatibility gene products of ”Nicotiana alata” are ribonucleases |journal=Nature |volume=342 |issue=6252 |pages=955–7 |year=1989 |pmid=2594090 |bibcode=1989Natur.342..955M |s2cid=4321558 |doi-access=free }}</ref> probably causes degradation of the [[ribosome|ribosomal]] [[RNA]] (rRNA) inside the pollen tube, in the case of identical male and female S alleles, and consequently pollen tube elongation is arrested, and the pollen grain dies.<ref name=”franklin-tong2003″/>
|
||
|
Within a decade of the initial confirmation their role in GSI, proteins belonging to the same RNase gene family were also found to cause pollen rejection in species of [[Rosaceae]] and [[Plantaginaceae]]. Despite initial uncertainty about the common ancestry of RNase-based SI in these distantly related plant families, phylogenetic studies<ref name=”igic2001″>{{cite journal |doi=10.1073/pnas.231386798 |author1=Igic, B. |author2=J. R. Kohn |name-list-style=amp |title=Evolutionary relationships among self-incompatibility RNases |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=98 |issue=23 |pages=13167–71 |year=2001 |pmid=11698683 |pmc=60842 |doi-access=free }}</ref> and the finding of shared male determinants (”’F-box proteins”’)<ref name=”qiao2004b”>{{cite journal |doi=10.1105/tpc.104.024919 |author=Qiao, H., F. Wang, L. Zhao, J. Zhou, Z. Lai, Y. Zhang, T. P. Robbins, and Y. Xue |title=The F-Box Protein AhSLF-S2 Controls the Pollen Function of S-RNase–Based Self-Incompatibility |journal=Plant Cell |volume=16 |issue=9 |pages=2307–22 |year=2004 |pmid=15308757 |pmc=520935 }}</ref><ref name=”ushijima”>{{cite journal |doi=10.1111/j.1365-313X.2004.02154.x |author=Ushijima, K., H. Yamane, A. Watari, E. Kakehi, K. Ikeda, N. R. Hauck, A. F. Iezzoni, and R. Tao |title=The S haplotype-specific F-box protein gene, SFB, is defective in self-compatible haplotypes of ”Prunus avium” and ”P. mume” |journal=Plant J. |volume=39 |issue=4 |pages=573–86 |year=2004 |pmid=15272875 }}</ref><ref name=”sijacic”>{{cite journal |doi=10.1038/nature02523 |author=Sijacic, P., X. Wang, A. L. Skirpan, Y. Wang, P. E. Dowd, A. G. McCubbin, S. Huang, and T. Kao |title=Identification of the pollen determinant of S-RNase-mediated self-incompatibility |journal=Nature |volume=429 |issue=6989 |pages=302–5 |year=2004 |pmid=15152253 |bibcode=2004Natur.429..302S |s2cid=4427123 }}</ref> strongly supported [[homology]] across [[eudicots]]. Therefore, this mechanism likely arose approximately 90 million years ago, and is the inferred ancestral state for approximately 50% of all plant species.<ref name=”igic2001″/>
|
Within a decade of the initial confirmation their role in GSI, proteins belonging to the same RNase gene family were also found to cause pollen rejection in species of [[Rosaceae]] and [[Plantaginaceae]]. Despite initial uncertainty about the common ancestry of RNase-based SI in these distantly related plant families, phylogenetic studies<ref name=”igic2001″>{{cite journal |doi=10.1073/pnas.231386798 |author1=Igic, B. |author2=J. R. Kohn |name-list-style=amp |title=Evolutionary relationships among self-incompatibility RNases |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=98 |issue=23 |pages=13167–71 |year=2001 |pmid=11698683 |pmc=60842 |doi-access=free }}</ref> and the finding of shared male determinants (”’F-box proteins”’)<ref name=”qiao2004b”>{{cite journal |doi=10.1105/tpc.104.024919 |author=Qiao, H., F. Wang, L. Zhao, J. Zhou, Z. Lai, Y. Zhang, T. P. Robbins, and Y. Xue |title=The F-Box Protein AhSLF-S2 Controls the Pollen Function of S-RNase–Based Self-Incompatibility |journal=Plant Cell |volume=16 |issue=9 |pages=2307–22 |year=2004 |pmid=15308757 |pmc=520935 }}</ref><ref name=”ushijima”>{{cite journal |doi=10.1111/j.1365-313X.2004.02154.x |author=Ushijima, K., H. Yamane, A. Watari, E. Kakehi, K. Ikeda, N. R. Hauck, A. F. Iezzoni, and R. Tao |title=The S haplotype-specific F-box protein gene, SFB, is defective in self-compatible haplotypes of ”Prunus avium” and ”P. mume” |journal=Plant J. |volume=39 |issue=4 |pages=573–86 |year=2004 |pmid=15272875 }}</ref><ref name=”sijacic”>{{cite journal |doi=10.1038/nature02523 |author=Sijacic, P., X. Wang, A. L. Skirpan, Y. Wang, P. E. Dowd, A. G. McCubbin, S. Huang, and T. Kao |title=Identification of the pollen determinant of S-RNase-mediated self-incompatibility |journal=Nature |volume=429 |issue=6989 |pages=302–5 |year=2004 |pmid=15152253 |bibcode=2004Natur.429..302S |s2cid=4427123 }}</ref> strongly supported [[homology]] across [[eudicots]]. Therefore, this mechanism likely arose approximately 90 million years ago, and is the inferred ancestral state for approximately 50% of all plant species.<ref name=”igic2001″/><ref name=”steinbachs2002″>{{cite journal |author1=Steinbachs, J. E. |author2=K. E. Holsinger |name-list-style=amp |title=S-RNase-mediated gametophytic self-incompatibility is ancestral in eudicots |journal=Mol. Biol. Evol. |volume=19 |issue=6 |pages=825–9 |year=2002 |pmid=12032238 |doi=10.1093/oxfordjournals.molbev.a004139|doi-access=free }}</ref>
|
||
|
In the past decade, the predictions about the wide distribution of this mechanism of SI have been confirmed, placing additional support of its single ancient origin. Specifically, a style-expressed T2/S-RNase gene and pollen-expressed F-box genes are now implicated in causing SI among the members of [[Rubiaceae]], [[Rutaceae]],
|
In the past decade, the predictions about the wide distribution of this mechanism of SI have been confirmed, placing additional support of its single ancient origin. Specifically, a style-expressed T2/S-RNase gene and pollen-expressed F-box genes are now implicated in causing SI among the members of [[Rubiaceae]], [[Rutaceae]], and [[Cactaceae]]. Therefore, other mechanisms of SI are thought to be recently derived in eudicots plants, in some cases relatively recently.
|
||
|
====The S-glycoprotein mechanism====
|
====The S-glycoprotein mechanism====
|
||