Loss of pollen-S function in two self-compatible selections of Prunus avium is associated with deletion/mutation of an S haplotype-specific F-box gene
Loss of pollen-S function in two self-compatible selections of Prunus avium is associated with deletion/mutation of an S haplotype-specific F-box gene
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DOI：
10.1105/tpc.104.026963
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发表时间：
2005-01-01
期刊：
影响因子：
11.6
通讯作者：
Robbins, TP
中科院分区：
文献类型：
--
作者：
Sonneveld, T;Tobutt, KR;Robbins, TP
最近，S单倍型特异的F-box（SFB）基因被认为是核糖核酸酶介导的李属配子体自交不亲和花粉S特异性基因的候选基因。我们研究了甜樱桃（Prunus avium）的两个花粉部分突变单倍型。发现两者都保留了决定花柱特异性的S-RNase，但一个（JI 2434中的S-3'）具有包括单倍型特异性SFB基因的缺失，另一个（JI 2420中的S-4'）具有单倍型特异性SFB基因的移码突变，导致氨基酸取代和蛋白质的过早终止。这种高度多态性的基因的损失或显着改变，并伴随着花粉自交不亲和功能的损失提供了令人信服的证据，SFB基因编码的花粉特异性组分的自交不亲和在李属。这些功能丧失突变与SFB是非自身S-RNA酶的失活剂不一致，并且表明存在一般失活机制，其中SFB通过保护自身S-RNA酶免于失活而赋予特异性。
Recently, an S haplotype-specific F-box (SFB) gene has been proposed as a candidate for the pollen-S specificity gene of RNase-mediated gametophytic self-incompatibility in Prunus (Rosaceae). We have examined two pollen-part mutant haplotypes of sweet cherry (Prunus avium). Both were found to retain the S-RNase, which determines stylar specificity, but one (S-3' in JI 2434) has a deletion including the haplotype-specific SFB gene, and the other (S-4' in JI 2420) has a frame-shift mutation of the haplotype-specific SFB gene, causing amino acid substitutions and premature termination of the protein. The loss or significant alteration of this highly polymorphic gene and the concomitant loss of pollen self-incompatibility function provides compelling evidence that the SFB gene encodes the pollen specificity component of self-incompatibility in Prunus. These loss-of-function mutations are inconsistent with SFB being the inactivator of non-self S-RNases and indicate the presence of a general inactivation mechanism, with SFB conferring specificity by protecting self S-RNases from inactivation.