Tamari F, Shore J S
Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3.
Heredity (Edinb). 2004 May;92(5):380-5. doi: 10.1038/sj.hdy.6800390.
We explore the distribution of a style and pollen polygalacturonase in a number of distylous and homostylous species of Turnera, and two species of Piriqueta (Turneraceae). We show, using immunoblotting with antibodies made against these proteins, that the style polygalacturonase is specific to styles of short-styled plants of all the six distylous species of Turnera we have investigated. Styles of a somatic homostylous mutant derived from a short-styled plant do not possess the style polygalacturonase. Distylous P. caroliniana did not appear to possess this protein. We show that the pollen polygalacturonase, while associated with the short-styled morph in three species, is polymorphic among short-styled plants of T. krapovickasii, and absent from T. joelii, T. grandiflora and P. caroliniana. These data support a role for the style polygalacturonase in distyly, possibly in the incompatibility system, but cast doubt on any role for the pollen polygalacturonase. In concert with the predictions for the mode of origin, and the response of styles of homostylous species to pollen from long- and short-styled plants, we find that none of the homostylous species possess the style polygalacturonase. The pollen polygalacturonase does occur in some homostylous species, but not in others. It is not clear that the pollen polygalacturonase, however, provides a marker for the mode of origin of homostyly.
我们研究了多种长柱型和同型花柱型的时钟花属植物以及两种刺果藤属植物（时钟花科）中花柱和花粉多聚半乳糖醛酸酶的分布情况。我们利用针对这些蛋白质制备的抗体进行免疫印迹分析，结果表明，花柱多聚半乳糖醛酸酶是我们所研究的所有六种长柱型时钟花属植物中短花柱型植株的花柱所特有的。源自短花柱型植株的体细胞同型花柱突变体的花柱不具有花柱多聚半乳糖醛酸酶。长柱型的卡罗来纳刺果藤似乎不具有这种蛋白质。我们发现，花粉多聚半乳糖醛酸酶虽然在三个物种中与短花柱型形态相关，但在克拉波维茨基时钟花的短花柱型植株中具有多态性，而在乔氏时钟花、大花时钟花和卡罗来纳刺果藤中则不存在。这些数据支持花柱多聚半乳糖醛酸酶在花柱异长中发挥作用，可能与不亲和系统有关，但对花粉多聚半乳糖醛酸酶的作用提出了质疑。与对起源模式的预测以及同型花柱物种的花柱对长花柱型和短花柱型植株花粉的反应一致，我们发现没有一个同型花柱物种具有花柱多聚半乳糖醛酸酶。花粉多聚半乳糖醛酸酶在一些同型花柱物种中存在，但在其他物种中不存在。然而，尚不清楚花粉多聚半乳糖醛酸酶是否为同型花柱的起源模式提供了一个标记。
