Université catholique de Louvain, Earth and Life Institute, Croix du Sud 2-11, 1348 Louvain-la-Neuve, Belgium.
J Exp Bot. 2010 May;61(8):2145-55. doi: 10.1093/jxb/erq077. Epub 2010 May 7.
Due in part to recent progress in root genetics and genomics, increasing attention is being devoted to root system architecture (RSA) for the improvement of drought tolerance. The focus is generally set on deep roots, expected to improve access to soil water resources during water deficit episodes. Surprisingly, our quantitative understanding of the role of RSA in the uptake of soil water remains extremely limited, which is mainly due to the inherent complexity of the soil-plant continuum. Evidently, there is a need for plant biologists and hydrologists to develop together their understanding of water movement in the soil-plant system. Using recent quantitative models coupling the hydraulic behaviour of soil and roots in an explicit 3D framework, this paper illustrates that the contribution of RSA to root water uptake is hardly separable from the hydraulic properties of the roots and of the soil. It is also argued that the traditional view that either the plant or the soil should be dominating the patterns of water extraction is not generally appropriate for crops growing with a sub-optimal water supply. Hopefully, in silico experiments using this type of model will help explore how water fluxes driven by soil and plant processes affect soil water availability and uptake throughout a growth cycle and will embed the study of RSA within the domains of root hydraulic architecture and sub-surface hydrology.
由于根遗传学和基因组学的近期进展，人们越来越关注根系结构 (RSA) 以提高耐旱性。研究的重点通常集中在深根上，预计深根在缺水时期可以更好地利用土壤水资源。令人惊讶的是，我们对 RSA 在土壤水分吸收中的作用的定量理解仍然非常有限，这主要是由于土壤-植物连续体固有的复杂性。显然，植物生物学家和水文学家需要共同发展他们对土壤-植物系统中水分运动的理解。本文使用最近的定量模型，在明确的 3D 框架中耦合土壤和根系的水力行为，说明了 RSA 对根系水分吸收的贡献几乎无法与根系和土壤的水力特性分开。本文还认为，传统观点认为植物或土壤应该主导水分提取模式并不适用于在供水不足的情况下生长的作物。希望使用这种类型的模型进行计算机模拟实验将有助于探索由土壤和植物过程驱动的水流如何影响整个生长周期内的土壤水分可用性和吸收，并将 RSA 的研究纳入根系水力结构和地下水文领域。
