Klein D E, Freitas L, Da Cunha M
Centro de Biociências e Biotecnologia (CBB), Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacazes, RJ, Brazil.
Sex Plant Reprod. 2009 Sep;22(3):121-31. doi: 10.1007/s00497-009-0097-0. Epub 2009 May 20.
Heterostyly is a genetically controlled floral polymorphism usually associated with an incompatibility system. This set of features is known to occur in several angiosperm families, but some aspects of its biology has not been well studied. The present study investigates cellular aspects of the pollen-pistil interaction after compatible and incompatible pollinations of Psychotria nuda, to increase our knowledge of heteromorphic self-incompatibility (HetSI). The use of bright field, fluorescence and transmission electron microscopy methods allowed us to demonstrate that pollen tubes behave differently after incompatible and compatible pollinations. Pollen tubes were particularly distinct after incompatible pollinations of L- and S-morph flowers. Relative to compatible pollen tubes, incompatible L-morph tubes had a drastic reduction in cellular contents, but no cell rupture. Incompatible S-morph tubes exhibited dense cytoplasm in apical regions, as well as in other regions, accompanied by a rupture of the apex. These results support the hypothesis that L- and S-morph flowers have different incompatibility mechanisms during HetSI.
花柱异长是一种受遗传控制的花部多态性，通常与不亲和系统相关。已知这组特征存在于几个被子植物科中，但其生物学的某些方面尚未得到充分研究。本研究调查了裸九节（Psychotria nuda）在亲和与不亲和授粉后花粉与雌蕊相互作用的细胞层面情况，以增进我们对异型自交不亲和（HetSI）的了解。使用明场、荧光和透射电子显微镜方法使我们能够证明，花粉管在不亲和授粉和亲和授粉后的行为有所不同。在L型和S型花的不亲和授粉后，花粉管表现得尤为不同。相对于亲和花粉管，不亲和的L型花粉管细胞内容物急剧减少，但没有细胞破裂。不亲和的S型花粉管在顶端区域以及其他区域表现出致密的细胞质，同时伴有顶端破裂。这些结果支持了以下假设：在异型自交不亲和过程中，L型和S型花具有不同的不亲和机制。
