Hiscock S J, Doughty J, Willis A C, Dickinson H G
Department of Plant Sciences, University of Oxford, UK.
Planta. 1995;196(2):367-74. doi: 10.1007/BF00201397.
Two S(self-incompatibility)-family glycoproteins have been identified in stigmas of self-compatible (SC) Brassica napus L. by their ability to interact, in vitro, with a peptide fraction from the pollen coating containing a PCP7-like peptide, PCP7 (pollen coat peptide 7[kDa]) being a pollen coat peptide from self-incompatible (SI) Brassica oleracea L. which has been shown to interact with S-locus glycoproteins (SLGs). Electrophoretic purification and N-terminal amino-acid sequencing of these stigmatic glycoproteins confirmed one to be an SLG and the other to be a class 1 S-locus-related glycoprotein (SLR1). This is the first reported isolation of SLG and SLR1 proteins from SC B. napus and the first time that a PCP7-like peptide has been shown to interact with an S-class glycoprotein other than SLG. On the basis of these findings we suggest that an ability to interact with PCP7 or a PCP7-like peptide is a property of SLGs, SLR1s and possibly other S-glycoproteins and may thus provide a novel route to the identification of these glycoproteins in stigmatic extracts. The levels of the SLG in stigmas of SC B. napus were relatively much lower than the levels of the SLR1--the opposite to the situation in SI B. oleracea. This finding is discussed in terms of translational control of SLGs and SLR1, and the possible implications for self-incompatibility in B. oleracea and self-compatibility in B. napus.
通过体外与来自花粉包被的含有类PCP7肽的肽组分相互作用的能力，在自交亲和（SC）甘蓝型油菜的柱头中鉴定出两种S（自交不亲和）家族糖蛋白，PCP7（花粉包被肽7[千道尔顿]）是来自自交不亲和（SI）甘蓝的一种花粉包被肽，已证明其可与S位点糖蛋白（SLG）相互作用。对这些柱头糖蛋白进行电泳纯化和N端氨基酸测序，证实其中一种是SLG，另一种是1类S位点相关糖蛋白（SLR1）。这是首次报道从SC甘蓝型油菜中分离出SLG和SLR1蛋白，也是首次证明类PCP7肽可与除SLG之外的S类糖蛋白相互作用。基于这些发现，我们认为与PCP7或类PCP7肽相互作用的能力是SLG、SLR1以及可能其他S糖蛋白的特性，因此可能为在柱头提取物中鉴定这些糖蛋白提供一条新途径。SC甘蓝型油菜柱头中SLG的水平相对远低于SLR1的水平——这与SI甘蓝中的情况相反。从SLG和SLR1的翻译控制以及对甘蓝自交不亲和性和甘蓝型油菜自交亲和性的可能影响方面对这一发现进行了讨论。
