Spore Adhesion and Cell Wall Formation in Gelidium Floridanum (Rhodophyta, Gelidiales)
Spore Adhesion and Cell Wall Formation in Gelidium Floridanum (Rhodophyta, Gelidiales)
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DOI：
10.1007/s10811-006-9028-8
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发表时间：
2006-09
影响因子：
3.3
通讯作者：
Z. Bouzon;L. Ouriques;Eurico C. Oliveira
中科院分区：
文献类型：
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作者：
Z. Bouzon;L. Ouriques;Eurico C. Oliveira
孢子附着在基质上对于它们的萌发是必不可少的，因此，对于红藻的生命周期的完成是必不可少的。在大多数红藻中，孢子在没有细胞壁的情况下释放，在负责其初级附着的粘液鞘中。利用荧光标记的凝集素，我们确定碳水化合物残基和它们的位置在粘液和孢子ofGelidium floridanum细胞壁。用荧光素、甲苯胺蓝- O（AT-O）、阿辛蓝（AB）和过碘酸-希夫（PAS）对细胞壁形成和粘液成分进行了研究。在粘液中鉴定出α-D甘露糖、α-D葡萄糖、β-D半乳糖、N-乙酰氨基葡萄糖和N-乙酰氨基半乳糖。前两个糖残基在芽管的细胞壁中没有发现，但它们存在于假根的细胞壁上，表明它们对基质粘附的重要性。细胞壁在孢子附着后不久就产生了，开始是纤维素的极性沉积，并逐渐在孢子周围扩散，如calcofluor所示。细胞壁基质呈AB阳性，AT-O呈异染性，表明酸性多糖，而纤维素微纤维呈PAS阳性。细胞壁的极性解体触发了萌发过程。由于孢子是石花菜的自然繁殖形式，了解孢子附着的机制可能有助于这种珍贵海藻的培养。
The attachment of spores to a substratum is essential for their germination and, therefore, to the completion of the life cycle of the red algae. In most red algae, spores are liberated without a cell wall, within a sheath of mucilage which is responsible for their primary attachment. Utilizing fluorescent-labeled lectins, we identified carbohydrate residues and their locations in the mucilage and cell walls of spores ofGelidium floridanum. Cell wall formation and mucilage composition were studied with calcofluor, toluidine blue — O (AT-O), alcian blue (AB) and periodic acid-Schiff (PAS). In the mucilage we identifiedα-D mannose,α-D glucose,β-D-galactose, N-acetyl-glucosamine and N-acetyl-galactosamine. The first two sugar residues were not found in the cell wall of the germ tube but they were present on the rhizoid’s cell wall indicating their importance to substrate adhesion. A cell wall is produced soon after the spore’s attachment, beginning with a polar deposition of cellulose and its gradual spread around the spore as indicated by calcofluor. The cell wall matrix was positive to AB and metachromatic to AT-O, indicating acidic polysaccharides, while cellulose microfibrills were positive to PAS. A polar disorganization of the cell wall triggers the process of germination. As spores are the natural form of propagation ofGelidium, the understanding of the mechanisms of spore attachment may contribute to the cultivation of this valuable seaweed.