Abstract Folate derivatives exist in nature in a variety of polyglutamyl forms (Glun); the glutamyl tail is added to the folate molecule by folylpolyglutamate synthetase (FPGS), and removed by gamma-glutamyl hydrolase (GGH) isoforms in several compartments within the cell. Folate polyglutamylation affects the use of the folate cofactors and their transport in organisms, also impacting their bioavailability as vitamins in mammals; however, little is known about its regulation in plants. We explored the possible effect of genetic, developmental, and environmental factors on the Glun extent of the most prevalent folate in plants, 5-CH3-THF. We chose ripening and ethylene treatment in climacteric fruits, to assess developmental and environmental factors. Postharvest ripening increased short Glun tails, and ethylene gassing affected negatively long Glun tails. To evaluate genetic factors, we retrieved and compared the deduced FPGS and GGH sequences from 27 plants with known Glun profile and attempted to correlate their phylogenetic relation, number of isoforms, predicted localization, and primary sequence with the Glun profiles generated and gathered by this study. GGH sequences were quite conserved among plants, while FPGS diverged more. We postulate that the very long Glun tail found only in papaya is the result of very particular changes in one of the FPGS’s primary structure.

中文翻译：

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植物中叶酸多聚谷氨酰化的复杂性：收获后成熟和乙烯调节更年期水果中的多聚谷氨酰化谱，以及谷氨酰尾编辑酶的系统分析

摘要 叶酸衍生物以多种多聚谷氨酰形式（Glun）存在于自然界中；谷氨酰尾部通过叶酰聚谷氨酸合成酶 (FPGS) 添加到叶酸分子中，并通过细胞内几个隔室中的 γ-谷氨酰水解酶 (GGH) 异构体去除。叶酸多聚谷氨酰化影响叶酸辅因子的使用及其在生物体中的运输，也影响它们作为维生素在哺乳动物中的生物利用度；然而，人们对其在植物中的调节知之甚少。我们探讨了遗传、发育和环境因素对植物中最普遍的叶酸 5-CH3-THF 的 Glu 含量的可能影响。我们选择对更年期水果进行催熟和乙烯处理，以评估发育和环境因素。收获后成熟增加了短的 Glun 尾巴，和乙烯放气对长 Glu 尾部产生负面影响。为了评估遗传因素，我们检索并比较了 27 株具有已知 Glun 谱的植物推导出的 FPGS 和 GGH 序列，并试图将它们的系统发育关系、同种型数量、预测定位和一级序列与本研究生成和收集的 Glu 谱相关联. GGH序列在植物间相当保守，而FPGS差异较大。我们假设仅在木瓜中发现的非常长的 Glun 尾是 FPGS 主要结构之一发生非常特殊变化的结果。以及本研究生成和收集的具有 Glu 特征的初级序列。GGH序列在植物间相当保守，而FPGS差异较大。我们假设仅在木瓜中发现的非常长的 Glun 尾是 FPGS 主要结构之一发生非常特殊变化的结果。以及本研究生成和收集的具有 Glu 特征的初级序列。GGH序列在植物间相当保守，而FPGS差异较大。我们假设仅在木瓜中发现的非常长的 Glun 尾是 FPGS 主要结构之一发生非常特殊变化的结果。