Pereira-Silva Carlos Gabriel, Ballego-Campos Igor, Sakuragui Cássia Mônica, Gonçalves Eduardo Gomes, Paiva Elder Antônio Sousa
Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil.
Departamento de Botânica, Instituto de Biologia, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil.
Plants (Basel). 2023 Aug 10;12(16):2912. doi: 10.3390/plants12162912.
Araceae comprises a diverse group of plants that grow in various habitats, ranging from submerged aquatics to lithophytes. Thus, aroids are likely to show diverse glands acting in several plant-environment interactions, including colleters that protect young shoots. Based on this premise and the lack of studies regarding secretory structures in Araceae, we employed standard light and electron microscopy methods to test the hypothesis that colleters are present in . Our main goals were to identify mucilage glands in by conducting a detailed anatomical study of their structure, ultrastructure, and secretory activity. We found finger-like colleters in the apex of young leaves, spathes, and unexpanded cataphylls as well as secreting zones at the apex of expanded cataphylls, at the margins of non-fused cataphylls, and throughout the keels in two-keeled cataphylls. The colleters develop precociously and senesce shortly afterwards. Ultrastructural data and histochemistry confirmed the production of a polysaccharide-rich secretion that fills the spaces within the developing shoot. As far we know, this is the first time that colleters have been reported for Araceae. The functional roles of the secretion and the position of finger-like colleters concerning the 'precursor tip' of monocotyledons are discussed. Future research correlating secretory activity in colleters of species from different habitats might reveal a great diversity of mucilage glands with ecological and evolutionary significance to the family.
天南星科包含多种植物，它们生长在从沉水水生植物到石生植物等各种生境中。因此，天南星科植物可能具有多种腺体，在多种植物与环境的相互作用中发挥作用，包括保护嫩枝的集流分泌腺。基于这一前提以及缺乏关于天南星科分泌结构的研究，我们采用标准的光学显微镜和电子显微镜方法来检验集流分泌腺存在于……的假设。我们的主要目标是通过对其结构、超微结构和分泌活性进行详细的解剖学研究，来鉴定……中的黏液腺。我们在幼叶顶端、佛焰苞和未展开的叶鞘中发现了指状集流分泌腺，以及在展开叶鞘的顶端、未融合叶鞘的边缘以及双龙骨叶鞘的整个龙骨处发现了分泌区。集流分泌腺发育早熟，随后不久就衰老。超微结构数据和组织化学证实产生了富含多糖的分泌物，填充了发育中的嫩枝内的空间。据我们所知，这是首次报道天南星科植物有集流分泌腺。本文讨论了分泌物的功能作用以及指状集流分泌腺相对于单子叶植物“前体顶端”的位置。未来对来自不同生境物种的集流分泌腺分泌活性进行关联研究，可能会揭示出对该科具有生态和进化意义的黏液腺的巨大多样性。
