Root architecture remodelling is critical for forage moisture in water-limited soil. DEEPER ROOTING 1 (DRO1) in Oryza, Arabidopsis, and Prunus has been reported to improve drought avoidance by promoting roots to grow downward and acquire water from deeper soil. In the present study, we found that ZmDRO1 responded more strongly to abscisic acid (ABA)/drought induction in Zea mays ssp. mexicana, an ancestral species of cultivated maize, than in B73. It was proposed that this is one of the reasons why Zea mays ssp. mexicana has a more noticeable change in the downward direction angle of the root and fewer biomass penalties under water-deficient conditions. Thus, a robust, synthetic ABA/drought-inducible promoter was used to control the expression of ZmDRO1^B73 in Arabidopsis and cultivated maize for drought-resistant breeding. Interestingly, ABA-inducible ZmDRO1 promoted a larger downward root angle and improved grain yield by more than 40% under water-limited conditions. Collectively, these results revealed that different responses to ABA/drought induction of ZmDRO1 confer different drought avoidance abilities, and we demonstrated the application of ZmDRO1 via an ABA-inducible strategy to alter the root architecture of modern maize to improve drought adaptation in the field.

中文翻译：

---

ABA-inducible DEEPER ROOTING 1 提高了玉米对缺水的适应能力

根系结构重塑对于限水土壤中的草料水分至关重要。据报道，水稻、拟南芥和李属中的DEEPER ROOTING 1 ( DRO1 )通过促进根部向下生长并从更深的土壤中获取水分来改善干旱避免。在本研究中，我们发现ZmDRO1对Zea mays ssp中的脱落酸 (ABA)/干旱诱导反应更强烈。mexicana是栽培玉米的祖先品种，比 B73 中的要好。有人提出这是Zea mays ssp的原因之一。墨西哥在缺水条件下，根的向下方向角度变化更明显，生物量损失更少。因此，一种稳健的合成 ABA/干旱诱导型启动子用于控制ZmDRO1 ^B73在拟南芥和栽培玉米中的表达，用于抗旱育种。有趣的是，ABA诱导的ZmDRO1在限水条件下促进了更大的向下根角并提高了超过40%的谷物产量。总的来说，这些结果表明ZmDRO1对 ABA/干旱诱导的不同反应赋予了不同的干旱避免能力，我们展示了ZmDRO1的应用通过 ABA 诱导策略改变现代玉米的根系结构，以改善田间的干旱适应。