The plant hormone abscisic acid (ABA) regulates many processes of plant growth and development. ABA receptors have been identified in studies of the ABA response of stomatal movement, but the underlying mechanisms of ABA-regulated root growth and development are unclear. To address these questions, we screened for Arabidopsis thaliana mutants based on the sensitivity of root growth to exogenous ABA, using ethyl methanesulfonate-mutagenized (EMS) and T-DNA insertion mutant libraries. We identified 11 mutants, termed roa1–roa11, with Root growth Overly sensitive to ABA (ROA) phenotypes, and cloned two of the ROA genes, one by thermal asymmetric interlaced PCR technology (ROA3) and the other by map-based cloning (ROA9). The roa mutants were also found to have defects in other major ABA responses, including ABA-mediated seed germination and drought resistance. The roa mutants provide crucial genetic material for further studies of ABA signaling and regulatory mechanisms in root growth and development.

中文翻译：

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拟南芥根相关突变体的表征揭示了植物发育和抗旱性的 ABA 调控

植物激素脱落酸（ABA）调节植物生长发育的许多过程。ABA 受体已在气孔运动的 ABA 反应研究中得到鉴定，但 ABA 调节根生长和发育的潜在机制尚不清楚。为了解决这些问题，我们基于根生长对外源 ABA 的敏感性，使用甲磺酸乙酯诱变 (EMS) 和 T-DNA 插入突变体文库筛选了拟南芥突变体。我们鉴定了 11 个突变体，称为 roa1-roa11，根生长对 ABA (ROA) 表型过度敏感，并克隆了两个 ROA 基因，一个通过热不对称交错 PCR 技术 (ROA3)，另一个通过基于图谱的克隆 (ROA9) ）。还发现 roa 突变体在其他主要的 ABA 反应中存在缺陷，包括 ABA 介导的种子萌发和抗旱性。roa 突变体为进一步研究根生长和发育中的 ABA 信号传导和调节机制提供了重要的遗传材料。