Acid mine drainage (AMD) is a huge environmental problem in mountain-top mining regions worldwide, including the Appalachian Mountains in the United States. This study applied a genome-wide association study (GWAS) to uncover genomic loci in Arabidopsis associated with tolerance to AMD toxicity. We characterized five major root phenotypes—cumulative root length, average root diameter, root surface area, root volume, and primary root length—in 180 Arabidopsis accessions in response to AMD-supplemented growth medium. GWAS of natural variation in the panel revealed genes associated with tolerance to an acidic environment. Most of these genes were transcription factors, anion/cation transporters, metal transporters, and unknown proteins. Two T-DNA insertion mutants, At1g63005 (miR399b) and At2g05635 (DEAD helicase RAD3), showed enhanced acidity tolerance. Our GWAS and the reverse genetic approach revealed genes involved in conferring tolerance to coal AMD. Our results indicated that proton resistance in hydroponic conditions could be an important index to improve plant growth in acidic soil, at least in acid-sensitive plant species.

中文翻译：

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拟南芥酸排泄毒性暴露自然变异的全基因组关联研究及反向遗传学相关基因的验证

酸性矿山排水（AMD）在世界范围内的山顶采矿区（包括美国的阿巴拉契亚山脉）是一个巨大的环境问题。这项研究应用了全基因组关联研究（GWAS），以发现拟南芥中与AMD毒性耐受相关的基因组位点。我们对180种拟南芥（Arabidopsis）品种的5种主要根表型进行了表征-累积根长，平均根径，根表面积，根体积和主根长，以响应AMD补充的生长培养基。小组中自然变化的GWAS揭示了与酸性环境耐受性相关的基因。这些基因大多数是转录因子，阴离子/阳离子转运蛋白，金属转运蛋白和未知蛋白质。两个T-DNA插入突变体At1g63005（miR399b）和At2g05635（DEAD解旋酶RAD3）显示出增强的酸度耐受性。我们的GWAS和逆向遗传方法揭示了与赋予煤AMD耐受性有关的基因。我们的结果表明，在水耕条件下的质子抗性可能是改善酸性土壤中植物生长的重要指标，至少对于酸敏感的植物而言。