Arbuscular mycorrhizal fungi (AMF) regulate root hair formation in host plants, whereas the underlying mechanisms are unknown at the molecular level. The present study aimed to analyze the molecular change in trifoliate orange ( Poncirus trifoliata ) seedlings after inoculated with Clariodeoglomus etunicatum (C_e) and Funneliformis mosseae (F_m) for 3 months. We analyzed RNA sequences in lateral root tips from non-mycorrhizal and mycorrhizal plants, then randomly screened and verified 10 differentially expressed genes (DEGs) using quantitative real-time PCR (qRT-PCR). The results showed that both fungal species increased root hair density and length in all orders of root classes (except 2nd lateral roots in C_e treatment), as well as root biomass and phosphorus (P) content in leaves and roots. We identified 1300 and 1810 DEGs in plants inoculated with C_e and F_m and validated transcriptome data using qRT-PCR, where 21, 19, and 10 DEGs were associated with P, auxins, and expansins, respectively. The most downregulated and upregulated DEGs associated with P encoded acid phosphatase and phosphate transporter, respectively. The ABC transporter was the most upregulated DEG associated with auxin metabolism. Among the DEGs associated with expansins, 50% each were upregulated and downregulated. These findings revealed that mycorrhiza colonization elicited molecular changes in improved root hairs of trifoliate orange in association with phosphorus, auxin, and expansins.

中文翻译：

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转录组分析显示丛枝菌根真菌可改善三叶橙幼苗的根毛生长

丛枝菌根真菌 (AMF) 调节寄主植物根毛的形成，而其潜在机制在分子水平上尚不清楚。本研究旨在分析三叶橙 (Poncirus trifoliata) 幼苗接种 Clariodeoglomus etunicatum (C_e) 和 Funneliformis mosseae (F_m) 3 个月后的分子变化。我们分析了来自非菌根和菌根植物侧根尖的 RNA 序列，然后使用实时定量 PCR (qRT-PCR) 随机筛选和验证了 10 个差异表达基因 (DEG)。结果表明，这两种真菌都增加了所有根类（C_e 处理中的第 2 侧根除外）的根毛密度和长度，以及叶和根中的根生物量和磷 (P) 含量。我们在接种 C_e 和 F_m 的植物中鉴定了 1300 和 1810 个 DEG，并使用 qRT-PCR 验证了转录组数据，其中 21、19 和 10 个 DEG 分别与 P、生长素和扩展蛋白相关。与 P 相关的最下调和上调的 DEG 分别编码酸性磷酸酶和磷酸盐转运蛋白。ABC 转运蛋白是与生长素代谢相关的最上调的 DEG。在与扩展蛋白相关的 DEG 中，各有 50% 被上调和下调。这些发现表明，菌根定植引发了与磷、生长素和扩展蛋白相关的三叶橙改良根毛的分子变化。与 P 相关的最下调和上调的 DEG 分别编码酸性磷酸酶和磷酸盐转运蛋白。ABC 转运蛋白是与生长素代谢相关的最上调的 DEG。在与扩展蛋白相关的 DEG 中，各有 50% 被上调和下调。这些发现表明，菌根定植引发了与磷、生长素和扩展蛋白相关的三叶橙改良根毛的分子变化。与 P 相关的最下调和上调的 DEG 分别编码酸性磷酸酶和磷酸盐转运蛋白。ABC 转运蛋白是与生长素代谢相关的最上调的 DEG。在与扩展蛋白相关的 DEG 中，各有 50% 被上调和下调。这些发现表明，菌根定植引发了与磷、生长素和扩展蛋白相关的三叶橙改良根毛的分子变化。