Dipartimento di Biologia e.s., Università degli Studi di Bologna, Via Irnerio 42, 40126 Bologna, Italy.
Amino Acids. 2010 Feb;38(2):659-67. doi: 10.1007/s00726-009-0426-5. Epub 2009 Dec 18.
The polyamine (PA) content and the transglutaminase (TGase) activity have been investigated in Pyrus communis pollination with compatible and self-incompatible (SI) pollen in order to deepen their possible involvement in the progamic phase of plant reproduction. The PA distribution as free, perchloric acid (PCA)-soluble and PCA-insoluble fractions in ungerminated (UGP), germinating pollen (GP), styles and pollinated styles with compatible and SI pollens is discussed in the light of a possible role during pollination. Generally, the conjugated PAs both in PCA-soluble and PCA-insoluble fractions were higher than the free form. Within the conjugated PAs, the PCA-insoluble ones were the highest with the exception of the not pollinated styles. As TGase mediates some of the effects of PAs by covalently binding them to proteins, the activity of this enzyme, never checked before in styles and pollinated styles, was examined. In the SI styles, the TGase activity is higher in comparison to style-pollinated with compatible pollen, and high molecular mass cross-linked products were formed, suggesting an involvement of TGase in SI response. This is the first evidence on the presence of this enzyme activity in not pollinated and pollinated styles.
为了深入研究多胺（PA）和转谷氨酰胺酶（TGase）在梨花粉授粉过程中的作用，我们对亲和花粉和自交不亲和（SI）花粉授粉的梨花粉中的 PA 含量和 TGase 活性进行了研究。我们探讨了未萌发花粉（UGP）、萌发花粉（GP）、花柱和亲和授粉及 SI 授粉花柱中游离态、高氯酸（PCA）可溶态和 PCA 不溶态 PA 的分布情况，以及它们在授粉过程中可能的作用。总的来说，PCA 可溶态和 PCA 不溶态结合态 PA 均高于游离态 PA。在结合态 PA 中，除未授粉花柱外，PCA 不溶态 PA 含量最高。由于 TGase 通过共价结合 PA 来介导其部分作用，我们检测了之前从未在花柱和授粉花柱中检测过的这种酶的活性。与亲和花粉授粉的花柱相比，SI 花柱中的 TGase 活性更高，并且形成了高分子质量的交联产物，这表明 TGase 参与了 SI 反应。这是首次在未授粉和授粉花柱中存在这种酶活性的证据。
