Colleters are secretory structures that play a role in protecting meristems from dehydration. Little attention has been given to the effect of seasonal variation on colleter exudates. Therefore, this study aimed to characterise the main chemical groups found in colleter exudates as well as to correlate the chemical nature of the secretion with seasonal variation. We used Myrcia splendens as a model to understand seasonal variation in colleter exudates. For that, meristems and shoot apices of M. splendens were collected and subjected to standard anatomical techniques. In M. splendens, colleters arise from protodermal cells and are similar to trichomes. Mature colleters are conic and composed of a short stalk and a long secretory head. Histochemical analyses found that colleter exudates differed according to the seasonality. Composition of the secretions was more diverse in the dry season than in the wet season. During the dry season, colleters secreted five different compounds (i.e. total polysaccharides, mucilage–pectins, total proteins, total lipids and phenolic compounds), whereas in the wet season, only three compounds were found (i.e. total proteins, total lipids and phenolic compounds). Our study extends what was known in earlier works, demonstrating changes in colleter exudates due to environmental seasonality.

中文翻译：

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Myrcia splendens（桃金娘科）收集器渗出液的季节性变化

收集器是在保护分生组织免于脱水方面发挥作用的分泌结构。很少关注季节性变化对收集器渗出液的影响。因此，本研究旨在表征在收集器渗出液中发现的主要化学基团，并将分泌物的化学性质与季节性变化相关联。我们使用 Myrcia splendens 作为模型来了解收集器渗出液的季节性变化。为此，收集了 M. splendens 的分生组织和芽尖，并对其进行了标准解剖技术。在 M. splendens 中，colleters 来自原始真皮细胞，类似于毛状体。成熟的收集器是圆锥形的，由短茎和长分泌头组成。组织化学分析发现，收集器渗出液因季节性而异。与雨季相比，旱季分泌物的成分更加多样化。在旱季，收集者分泌了五种不同的化合物（即总多糖、粘液果胶、总蛋白、总脂质和酚类化合物），而在雨季，仅发现三种化合物（即总蛋白、总脂质和酚类化合物） ）。我们的研究扩展了早期工作中已知的内容，展示了由于环境季节性而导致的收集器渗出液的变化。