POLLINATION IN SPECIES WITH DRY STIGMAS - THE NATURE OF THE EARLY STIGMATIC RESPONSE AND THE PATHWAY TAKEN BY POLLEN TUBES
POLLINATION IN SPECIES WITH DRY STIGMAS - THE NATURE OF THE EARLY STIGMATIC RESPONSE AND THE PATHWAY TAKEN BY POLLEN TUBES
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DOI：
10.1111/j.1469-8137.1992.tb02941.x
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发表时间：
1992-07-01
期刊：
影响因子：
9.4
通讯作者：
DICKINSON, HG
中科院分区：
文献类型：
--
作者：
ELLEMAN, CJ;FRANKLINTONG, V;DICKINSON, HG
已经在五个被认为具有干燥柱头表面的物种中研究了花粉粒、花粉管和柱头表面之间的相互作用；甘蓝 (Brassica oleracea L.)、拟南芥 (Arabidopsis thaliana (L.))、Heynh、罂粟 (Papaver rhoeas L.)、波斯菊 (Cosmos bipinnatus Cav)。在甘蓝和拟南芥中，对授粉的柱头反应包括乳头状细胞质中的事件和籽粒下方柱头表面的变化。特别是，细胞壁的特殊外部元件在花粉管穿透之前膨胀。花粉管穿过花粉涂层的“脚”进入，在壁的内部和外部元件之间产生的空间中生长，并延伸到乳头的基部，在那里它进入下面细胞层的中间层。然而，在拟南芥中，经常发现管穿透柱头细胞壁的所有成分，这一事件以前仅在甘蓝的未成熟柱头中记录到。在涉及强S（不亲和性）等位基因的自花不亲和甘蓝的自花授粉中，乳头细胞壁不会发生任何变化。在大黄花中，柱头表面通过在角质层下方分泌电子透明物质来响应自花授粉和异花授粉，导致其与柱头细胞壁的外表面分离。然后花粉管穿透角质层并在由此产生的空间中向乳头基部生长。这些管在传播组织中继续在细胞间生长，传播组织水平地位于乳头下方的射线中。在菊科植物、C. bipinnatus 和 H. annuus 中，柱头和花粉都通过产生大量不电子透明基质来响应授粉，这经常导致单个乳头粘附在一起。花粉管是在相容和不相容的种内授粉后形成的，生长到该基质中并朝向乳头的基部。在那里，与所研究的其他植物一样，它们在细胞间生长并进入花柱的传播组织。根据当前对被子植物授粉期间运作机制的观点以及柱头反应对自交不亲和机制功能的重要性的观点，讨论了这些发现。
Interaction between the pollen grain, pollen tube and the stigma surface has been studied in five species regarded as possessing dry stigma surfaces; Brassica oleracea L., Arabidopsis thaliana (L.), Heynh, Papaver rhoeas L., Cosmos bipinnatus Cav. and Helianthus annuus L.In B. oleracea and A. thaliana, stigmatic response to pollination includes events in the papillar cytoplasm and changes to the stigmatic surface beneath the grain. In particular a specialized outer element of the cell wall expands prior to pollen tube penetration. The pollen tube, which enters through a 'foot' of pollen coating, grows in a space generated between an inner and the outer element of the wall and extends to the base of the papilla where it enters the middle lamellae of the subjacent cell layer. However, in A. thaliana tubes frequently were seen to penetrate all components of the stigmatic cell wall, an event only previously recorded in immature stigmas of B. oleracea. In self pollinations of self-incompatible B. oleracea involving strong S (incompatibility) alleles no changes take place in the papillar cell wall.In P. rhoeas the stigmatic surface responds to self and cross pollination by the secretion of electron-lucent material beneath the cuticle, causing it to become detached from the outer surface of the stigmatic cell wall. The pollen tubes then penetrate the cuticle and grow towards the base of the papilla in the space thus generated. The tubes continue to grow intercellularly in the transmitting tissue which lies horizontally in rays beneath the papillae.In members of the Compositae, C. bipinnatus and H. annuus, both stigma and pollen respond to pollination by producing copious quantities of an electron-opaque matrix, which frequently causes individual papillae to adhere together. Pollen tubes, which are formed following both compatible and incompatible intraspecific pollinations, grow into this matrix and toward the base of the papillae. There, in common with the other plants studied, they grow intercellularly and enter the transmitting tissue of the style.These findings are discussed in the light of current views of the mechanisms operating during angiosperm pollination and of the significance of the stigmatic response to the functioning of self-incompatibility mechanisms.