In this study we tested the hypotheses that root classes would exhibit distinctive anatomical and architectural responses to drought stress, and that those responses would vary along the root axes. The root systems of four maize (Zea mays L.) sweet corn genotypes designated SC1, SC2, SC3 and SC4 were phenotyped under well-watered and drought treatments in greenhouse mesocosms, permitting increasing stratification of moisture availability as the drought progressed. Anatomical and architectural responses to drought were evaluated for each root class. Lignin distribution was assessed by image processing of UV-illuminated root cross-sections acquired by laser ablation tomography. The two cultivars with less biomass reduction under drought, SC3 and SC4, substantially enhanced lateral root development along the apical segments of axial roots when plants were grown with drought stress. These segments grew into the deeper part of the mesocosm where more moisture was available. Apical segments of the axial and large lateral roots from drought-stressed plants were thicker and had greater theoretical axial water conductance than basal segments, especially in SC3 and SC4. Basal segments of crown roots of SC3 and SC4 showed increased lignification of the stele under drought. Root anatomical and architectural responses to drought are complex and vary among cultivars and root classes, and along root axes. Drought-induced proliferation of lateral roots on apical segments of axial roots would be expected to enhance deep water acquisition, while lignification of axial roots could help preserve axial water transport.

在这项研究中，我们测试了以下假设，即根类会对干旱胁迫表现出独特的解剖学和建筑学反应，并且这些反应会沿着根轴变化。四种玉米（ Zea mays）的根系L.) 指定为 SC1、SC2、SC3 和 SC4 的甜玉米基因型在温室中胚层中的水分充足和干旱处理下进行表型分析，随着干旱的进行，水分可用性的分层增加。评估了每个根类的解剖和结构对干旱的反应。通过激光烧蚀断层扫描获得的紫外线照射根横截面的图像处理来评估木质素分布。当植物在干旱胁迫下生长时，干旱条件下生物量减少较少的两个品种 SC3 和 SC4 显着增强了沿轴根顶端段的侧根发育。这些部分生长到中宇宙的较深部分，那里有更多的水分可用。干旱胁迫植物的轴向根和大侧根的顶节比基节更厚，并且具有更大的理论轴向水导率，尤其是在 SC3 和 SC4 中。SC3和SC4冠根的基部在干旱条件下显示出增加的石碑木质化。根系对干旱的解剖和结构反应是复杂的，并且在品种和根类之间以及沿根轴变化。干旱引起的轴根顶端侧根的增殖预计会增强深水的获取，而轴根的木质化可以帮助保持轴向水的输送。根系对干旱的解剖和结构反应是复杂的，并且在品种和根类之间以及沿根轴变化。干旱引起的轴根顶端侧根的增殖预计会增强深水的获取，而轴根的木质化可以帮助保持轴向水的输送。根系对干旱的解剖和结构反应是复杂的，并且在品种和根类之间以及沿根轴变化。干旱引起的轴根顶端侧根的增殖预计会增强深水的获取，而轴根的木质化可以帮助保持轴向水的输送。