Plant & Crop Sciences, School of Biosciences, University of Nottingham, Nottingham, LE12 5RD, UK.
Centre for Plant Integrative Biology (CPIB), University of Nottingham, Nottingham, LE12 5RD, UK.
Nat Commun. 2018 Apr 12;9(1):1409. doi: 10.1038/s41467-018-03851-3.
Phosphate (P) is an essential macronutrient for plant growth. Roots employ adaptive mechanisms to forage for P in soil. Root hair elongation is particularly important since P is immobile. Here we report that auxin plays a critical role promoting root hair growth in Arabidopsis in response to low external P. Mutants disrupting auxin synthesis (taa1) and transport (aux1) attenuate the low P root hair response. Conversely, targeting AUX1 expression in lateral root cap and epidermal cells rescues this low P response in aux1. Hence auxin transport from the root apex to differentiation zone promotes auxin-dependent hair response to low P. Low external P results in induction of root hair expressed auxin-inducible transcription factors ARF19, RSL2, and RSL4. Mutants lacking these genes disrupt the low P root hair response. We conclude auxin synthesis, transport and response pathway components play critical roles regulating this low P root adaptive response.
磷（P）是植物生长所必需的大量营养素。根系采用适应性机制在土壤中寻找 P。根毛伸长尤为重要，因为 P 是不可移动的。在这里，我们报告生长素在拟南芥响应低外部 P 时，在促进根毛生长中起着关键作用。破坏生长素合成（taa1）和运输（aux1）的突变体削弱了低 P 根毛反应。相反，在侧根冠和表皮细胞中靶向表达 AUX1 可挽救 aux1 中低 P 的反应。因此，生长素从根尖向分化区的运输促进了生长素依赖性毛发对低 P 的反应。低外部 P 导致根毛表达的生长素诱导转录因子 ARF19、RSL2 和 RSL4 的诱导。缺乏这些基因的突变体破坏了低 P 根毛反应。我们得出结论，生长素的合成、运输和响应途径成分在调节这种低 P 根适应性反应中起着关键作用。
