The RHV region of S-RNase in the European pear (Pyrus communis) is not required for the determination of specific pollen rejection
The RHV region of S-RNase in the European pear (Pyrus communis) is not required for the determination of specific pollen rejection
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DOI：
10.1007/s00497-004-0225-9
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发表时间：
2004-08
影响因子：
--
通讯作者：
A. Zisovich;R. Stern;G. Sapir;S. Shafir;M. Goldway
中科院分区：
文献类型：
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作者：
A. Zisovich;R. Stern;G. Sapir;S. Shafir;M. Goldway
在配子体自交不亲和系统中，S-RNase以单倍型特异的方式抑制花柱中自交花粉管的生长。S-RNase赋予其特异性的机制尚不清楚。然而，一个高变区（蔷薇科的RHV和茄科的HVa-HVb），在许多克隆的S-RNase等位基因之间的差异已被提出参与赋予S-RNase的S-单倍型特异性。S-RNases之间的区域交换实验和酶的晶体学支持这一假设。然而，最近发现欧洲梨（Pyrus communis）的Sn-RNase和Si-RNase等位基因推导的氨基酸序列具有相同的RHV。在本研究中，它表明，Sn-RNase不阻止受精的Si花粉单倍型，从而提出了一个案例，其中RHV是不需要的确定特定的花粉排斥S-RNase，并暗示，在酶的其他区域可能是足够的这种特异性。
In the gametophytic self-incompatibility system, growth of self-pollen tubes in the style is inhibited in a haplotype-specific manner by S-RNase. The mechanism by whichS-RNase confers its specificity is unknown. However, a hypervariable region (RHV in Rosaceae and HVa-HVb in Solanaceae) that differs among the many cloned S-RNase alleles has been proposed to be involved in conferring theS-haplotype specificity of the S-RNase. Region swapping experiments between S-RNases and crystallography of the enzyme support this assumption. However, the deduced amino acid sequences ofSn-RNaseandSi-RNasealleles from the European pear (Pyrus communis) were recently found to have an identical RHV. In the present study it is shown that Sn-RNase does not prevent fertilization bySi-pollen haplotype, thus presenting a case in which RHV is not required for the determination of specific pollen rejection by S-RNase, and implying that other regions in the enzyme may be sufficient for this specificity.