Folates are one of the essential micronutrients for all living organisms. Due to inadequate dietary intake, folate deficiency remains prevalent in humans. Genetically diverse germplasms can potentially be used as parents in breeding programs and also for understanding the folate regulatory network. Therefore, we investigated the natural genetic diversity of folates and their physiological regulation in pak choi (Brassica rapa subsp. Chinensis) germplasm. The total folate concentration ranged from 52.7 μg 100 gFW^–1 to 166.9 μg 100 gFW^–1, with 3.2-fold variation. The main folate vitamer was represented by 5-CH₃-H₄folate, with 4.5-fold variation. The activities of GTP cyclohydrolase I and aminodeoxy chorismate synthase, the first step of folate synthesis, were high in high folate accessions and low in low folate accessions. Analysis of the transcription levels of 11 genes associated with folate metabolism demonstrated that the difference in folate concentrations may be primarily controlled at the post-transcriptional level. A general correlation between total folate and their precursors was observed. Folate diversity and chlorophyll content were tightly regulated through the methyl cycle. The diverse genetic variation in pak choi germplasm indicated the great genetic potential to integrate breeding programs for folate biofortification and unravel the physiological basis of folate homeostasis in planta.

中文翻译：

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白菜种质中叶酸的遗传和生理调控。

叶酸是所有活生物体必需的微量营养素之一。由于饮食摄入不足，叶酸缺乏症在人类中仍然很普遍。遗传多样性的种质有可能在育种计划中用作亲本，也可用于了解叶酸调节网络。因此，我们研究叶酸的天然遗传多样性和青菜的生理调节（芜菁亚种。羊草）种质资源。叶酸总浓度范围从52.7μg100 gFW ^–1到166.9μg100 gFW ^–1，变化为3.2倍。叶酸维他命主要成分为5-CH ₃ -H ₄叶酸，变化4.5倍。叶酸合成的第一步，GTP环水解酶I和氨基脱氧分支酸合酶的活性在高叶酸含量中较高，而在低叶酸含量中较低。对与叶酸代谢相关的11个基因的转录水平的分析表明，叶酸浓度的差异可能主要控制在转录后水平。观察到总叶酸与其前体之间的一般相关性。叶酸多样性和叶绿素含量通过甲基循环受到严格调节。白菜种质资源的多样性遗传变异表明整合叶酸生物强化育种程序和揭示植物叶酸稳态生理基础的巨大遗传潜力。