Analyzing Lateral Root Development: How to Move Forward

Abstract

Roots are important to plants for a wide variety of processes, including nutrient and water uptake, anchoring and mechanical support, storage functions, and as the major interface between the plant and various biotic and abiotic factors in the soil environment. Therefore, understanding the development and architecture of roots holds potential for the manipulation of root traits to improve the productivity and sustainability of agricultural systems and to better understand and manage natural ecosystems. While lateral root development is a traceable process along the primary root and different stages can be found along this longitudinal axis of time and development, root system architecture is complex and difficult to quantify. Here, we comment on assays to describe lateral root phenotypes and propose ways to move forward regarding the description of root system architecture, also considering crops and the environment.Root system architecture is a key determinant of nutrient and water use efficiency and describes, on a macro scale, the organization of the primary root and root-and stemderived branches where they are present in monocots and dicots (Hochholdinger et al., 2004;De Smet et al., 2006;Hochholdinger and Zimmermann, 2008;Pé ret et al., 2009;Coudert et al., 2010

3D phenotyping and quantitative trait locus mapping identify core regions of the rice genome controlling root architecture

“…This knowledge gap exists primarily because of the difficulties in imaging root systems and in identifying relevant quantitative phenotypes from complex topologies (3,4,41,42). Computer simulations supported by empirical field work can suggest ideal root architectures, or ideotypes, that are best suited to a particular environment (10,(43)(44)(45)(46).…”

“…17, 27, and 54). The most successful applications of RSA research to agriculture undoubtedly will integrate knowledge gained from a number of complementary approaches (12,27,41,(55)(56)(57).…”

RootScape: A Landmark-Based System for Rapid Screening of Root Architecture in Arabidopsis

“…Root systems are integrated organs that adopt specific architectures to maximal foraging of the heterogeneous soil environment in different ways (Fitter, 1987;Fitter and Stickland, 1991;Lynch, 1995). More recently, new approaches have incorporated the measurement of many individual developmental traits that together comprise RSA (De Smet et al, 2012;Dubrovsky and Forde, 2012). For example, one recent report identified three fundamental components of RSA in generating complex topologies, including the contribution of lateral axes to branching, the rate and path of growth of the axis, and the increase in root surface area (Topp and Benfey, 2012).…”

“…Consequently, different methods and approaches have been developed in order to address this demand. Currently, three major approaches for phenotyping RSA are used (for review, see Zhu et al, 2011;De Smet et al, 2012). The first group of methods uses classical measures of RSA, which involve measurements of individual root traits.…”

Modeling root growth in granular soils: effects of root stiffness and packing fraction

“…Besides many other factors such as developmental instability on the cellular level [1], the mechanical interactions between a growing root and its surrounding soil can have major impact on the growth variability and plant biomass production [2][3][4][5][6]. In particular, the inhomogeneous structure of soil at the particle scale and broad distributions of contact forces can significantly affect root growth trajectories [7][8][9][10][11].…”