Root System Architecture and Abiotic Stress Tolerance: Current Knowledge in Root and Tuber Crops

Abstract

The challenge to produce more food for a rising global population on diminishing agricultural land is complicated by the effects of climate change on agricultural productivity. Although great progress has been made in crop improvement, so far most efforts have targeted above-ground traits. Roots are essential for plant adaptation and productivity, but are less studied due to the difficulty of observing them during the plant life cycle. Root system architecture (RSA), made up of structural features like root length, spread, number, and length of lateral roots, among others, exhibits great plasticity in response to environmental changes, and could be critical to developing crops with more efficient roots. Much of the research on root traits has thus far focused on the most common cereal crops and model plants. As cereal yields have reached their yield potential in some regions, understanding their root system may help overcome these plateaus. However, root and tuber crops (RTCs) such as potato, sweetpotato, cassava, and yam may hold more potential for providing food security in the future, and knowledge of their root system additionally focuses directly on the edible portion. Root-trait modeling for multiple stress scenarios, together with high-throughput phenotyping and genotyping techniques, robust databases, and data analytical pipelines, may provide a valuable base for a truly inclusive ‘green revolution.’ In the current review, we discuss RSA with special reference to RTCs, and how knowledge on genetics of RSA can be manipulated to improve their tolerance to abiotic stresses.

Multivariate analyses of root phenotype and dynamic transcriptome underscore valuable root traits and water‐deficit responsive gene networks in maize

“…We conducted signed gene co‐expression network analysis using the WGCNA (Khan et al., ) based on FPKM data. Genes with FPKM < 1 for all samples and a coefficient of variation cut‐off of 0.25 was removed prior to WGCNA analysis.…”

“…Khan et al, 2016) based on FPKM data. Genes with FPKM < 1 for all samples and a coefficient of variation cut-off of 0.25 was removed prior to WGCNA analysis.…”

Characterization of root traits for improvement of spring wheat in the Pacific Northwest

“…A better physiological understanding of root growth dynamics and architecture is crucial to optimize crop performance through the modification of below‐ground root traits adapted to environmental and climatic extremes (Khan, Gemenet, & Villordon, ; Postma, Schurr, & Fiorani, ; Uga et al., ). Nonetheless, root systems are not easily accessible for phenotyping specific traits in soil, either in the greenhouse or in natural field settings.…”

“…A better physiological understanding of root growth dynamics and architecture is crucial to optimize crop performance through the modification of below-ground root traits adapted to environmental and climatic extremes (Khan, Gemenet, & Villordon, 2016;Postma, Schurr, & Fiorani, 2014;Uga et al, Chochois, 2013a). Minirhizotrons are nondestructive in situ root phenotyping systems suitable for both greenhouse pots and field landscapes that enable the acquisition of highquality data on root growth, demography, and dynamics in a spatiotemporal context (Crocker et al, 2003;Polomski & Kuhn, 2002).…”

Assessing Root System Architecture of Wheat Seedlings Using A High-Throughput Root Phenotyping System

“…Roots serve as boundaries between plants and complex soil mediums. Aside from anchoring the plant to soil medium (Khan et al , 2016), another major function of the root is to provide plant access to nutrient and water uptake. Roots are also essential for forming symbioses with beneficial microbes in the rhizosphere and used as storage organs (Smith and De Smet, 2012; Khan et al , 2016).…”