SummaryIsoxaben is a pre‐emergent herbicide used to control broadleaf weeds. While the phytotoxic mechanism is not completely understood, isoxaben interferes with cellulose synthesis. Certain mutations in cellulose synthase complex proteins can confer isoxaben tolerance; however, these mutations can cause compromised cellulose synthesis and perturbed plant growth, rendering them unsuitable as herbicide tolerance traits. We conducted a genetic screen to identify new genes associated with isoxaben tolerance by screening a selection of Arabidopsis thaliana T‐DNA mutants. We found that mutations in a FERREDOXIN‐NADP(+) OXIDOREDUCTASE‐LIKE (FNRL) gene enhanced tolerance to isoxaben, exhibited as a reduction in primary root stunting, reactive oxygen species accumulation and ectopic lignification. The fnrl mutant did not exhibit a reduction in cellulose levels following exposure to isoxaben, indicating that FNRL operates upstream of isoxaben‐induced cellulose inhibition. In line with these results, transcriptomic analysis revealed a highly reduced response to isoxaben treatment in fnrl mutant roots. The fnrl mutants displayed constitutively induced mitochondrial retrograde signalling, and the observed isoxaben tolerance is partially dependent on the transcription factor ANAC017, a key regulator of mitochondrial retrograde signalling. Moreover, FNRL is highly conserved across all plant lineages, implying conservation of its function. Notably, fnrl mutants did not show a growth penalty in shoots, making FNRL a promising target for biotechnological applications in breeding isoxaben tolerance in crops.

中文翻译：

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fnr 样突变体通过启动线粒体逆行信号传导赋予异沙本耐受性


摘要异恶苯是一种芽前除草剂，用于控制阔叶杂草。虽然植物毒性机制尚不完全清楚，但异恶苯会干扰纤维素合成。纤维素合酶复合体蛋白中的某些突变可以赋予异恶本耐受性；然而，这些突变可能会导致纤维素合成受损并扰乱植物生长，使它们不适合作为除草剂耐受性性状。我们进行了基因筛选，通过筛选一系列基因来鉴定与异沙本耐受性相关的新基因拟南芥T-DNA 突变体。我们发现突变铁氧还蛋白-NADP ( + ）类氧化还原酶(联邦国家研究实验室) 基因增强了对异恶苯的耐受性，表现为初生根发育迟缓、活性氧积累和异位木质化的减少。这民族解放阵线突变体在接触 isoxaben 后并未表现出纤维素水平降低，表明 FNRL 在 isoxaben 诱导的纤维素抑制的上游发挥作用。与这些结果一致，转录组分析显示，在民族解放阵线突变根。这民族解放阵线突变体表现出组成型诱导的线粒体逆行信号传导，并且观察到的异恶本耐受性部分依赖于转录因子 ANAC017，转录因子 ANAC017 是线粒体逆行信号传导的关键调节因子。此外，FNRL 在所有植物谱系中都高度保守，这意味着其功能是保守的。尤其，民族解放阵线突变体在芽中没有表现出生长损失，这使得 FNRL 成为生物技术应用育种作物异恶酯耐受性的有希望的目标。