Araya Takao, Kubo Takuya, von Wirén Nicolaus, Takahashi Hideki
Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA.
Molecular Plant Nutrition, Leibniz Institute of Plant Genetics and Crop Plant Research, D-06466 Gatersleben, Germany.
J Integr Plant Biol. 2016 Mar;58(3):254-65. doi: 10.1111/jipb.12433. Epub 2015 Nov 2.
Plant root development is strongly affected by nutrient availability. Despite the importance of structure and function of roots in nutrient acquisition, statistical modeling approaches to evaluate dynamic and temporal modulations of root system architecture in response to nutrient availability have remained as widely open and exploratory areas in root biology. In this study, we developed a statistical modeling approach to investigate modulations of root system architecture in response to nitrogen availability. Mathematical models were designed for quantitative assessment of root growth and root branching phenotypes and their dynamic relationships based on hierarchical configuration of primary and lateral roots formulating the fishbone-shaped root system architecture in Arabidopsis thaliana. Time-series datasets reporting dynamic changes in root developmental traits on different nitrate or ammonium concentrations were generated for statistical analyses. Regression analyses unraveled key parameters associated with: (i) inhibition of primary root growth under nitrogen limitation or on ammonium; (ii) rapid progression of lateral root emergence in response to ammonium; and (iii) inhibition of lateral root elongation in the presence of excess nitrate or ammonium. This study provides a statistical framework for interpreting dynamic modulation of root system architecture, supported by meta-analysis of datasets displaying morphological responses of roots to diverse nitrogen supplies.
植物根系发育受到养分有效性的强烈影响。尽管根系的结构和功能在养分获取中很重要，但评估根系结构对养分有效性响应的动态和时间调节的统计建模方法，在根系生物学中仍是广泛开放的探索领域。在本研究中，我们开发了一种统计建模方法来研究根系结构对氮有效性的调节。基于拟南芥中形成鱼骨状根系结构的主根和侧根的层次结构，设计了数学模型来定量评估根生长和根分支表型及其动态关系。生成了报告不同硝酸盐或铵浓度下根发育性状动态变化的时间序列数据集用于统计分析。回归分析揭示了与以下方面相关的关键参数：（i）氮限制或铵处理下主根生长的抑制；（ii）响应铵时侧根出现的快速进展；以及（iii）过量硝酸盐或铵存在时侧根伸长的抑制。本研究提供了一个统计框架来解释根系结构的动态调节，该框架得到了对显示根系对不同氮供应形态响应的数据集的荟萃分析的支持。
