Lopez-Valdivia Ivan, Rangarajan Harini, Vallebueno-Estrada Miguel, Lynch Jonathan P
Department of Plant Science, The Pennsylvania State University, University Park, PA, USA, 16802.
Department of Physiology and Cell Biology, Leibniz Institute for Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, 06466, Seeland, Germany.
Ann Bot. 2025 Aug 13. doi: 10.1093/aob/mcaf179.
Root phenotypes contribute to environmental adaptation. We hypothesized that root phenotypes of maize (Zea mays L. ssp. Mays) landraces reflect their adaptation to edaphic limitations in their native soil environments, and that some root phenotypes may confer broad edaphic adaptation.
We phenotyped the roots of maize landraces and used the functional-structural plant/soil model OpenSimRoot_v2 to simulate landraces and their native environments to analyze how root phene states interact with each other and with environment variables to regulate edaphic adaptation.
Landraces from low phosphorus regions have root phenotypes with shallow growth angles and greater nodal root numbers, allowing them to adapt to their native environments by improved topsoil foraging. We used machine learning algorithms to detect the most important phenotypes responsible for adaptation to multiple environments. The most important phene states responsible for stability across environments are large cortical cell size and reduced diameter of roots in nodes 5 and 6. When we dissected the components of root diameter, we observed that large cortical cell size improved growth by 28%, 23 % and 114%, while reduced cortical cell file number alone improved shoot growth by 137%, 66% and 216%, under drought, nitrogen and phosphorus stress, respectively. Functional-structural analysis of 96 maize landraces from the Americas, previously phenotyped in mesocosms in the greenhouse, suggested that parsimonious anatomical phenotypes, which reduce the metabolic cost of soil exploration, are the main phenotypes associated with adaptation to multiple environments, while root architectural phenotypes were related to adaptation to specific environments.
These results indicate that integrated root phenotypes with anatomical phene states that reduce the metabolic cost of soil exploration increase tolerance to edaphic stress across multiple environments and therefore would improve yield stability, regardless of their root architecture.
根系表型有助于植物适应环境。我们推测，玉米地方品种的根系表型反映了它们对原生土壤环境中土壤限制因素的适应情况，并且一些根系表型可能赋予广泛的土壤适应性。
我们对玉米地方品种的根系进行了表型分析，并使用功能 - 结构植物/土壤模型OpenSimRoot_v2模拟地方品种及其原生环境，以分析根系表型状态如何相互作用以及与环境变量相互作用来调节土壤适应性。
来自低磷地区的地方品种具有浅生长角度和更多节根数量的根系表型，使它们能够通过改善表土觅食来适应原生环境。我们使用机器学习算法来检测对多种环境适应最重要的表型。对跨环境稳定性最重要的表型状态是大的皮层细胞大小以及第5和第6节根直径减小。当我们剖析根直径的组成部分时，发现在干旱、氮和磷胁迫下，大的皮层细胞大小分别使生长提高了28%、23%和114%，而仅皮层细胞列数减少就分别使地上部生长提高了137%、66%和216%。对先前在温室中中型生态系统中进行表型分析的来自美洲的96个玉米地方品种进行功能 - 结构分析表明，减少土壤探索代谢成本的简约解剖学表型是与多种环境适应相关的主要表型，而根系结构表型与特定环境的适应有关。
这些结果表明，具有减少土壤探索代谢成本的解剖学表型状态的综合根系表型增加了对多种环境土壤胁迫的耐受性，因此无论其根系结构如何，都将提高产量稳定性。
