Genetic components of root architecture and anatomy adjustments to water‐deficit stress in spring barley

Abstract

Roots perform vital roles for adaptation and productivity under water‐deficit stress, even though their specific functions are poorly understood. In this study, the genetic control of the nodal‐root architectural and anatomical response to water deficit were investigated among diverse spring barley accessions. Water deficit induced substantial variations in the nodal root traits. The cortical, stele, and total root cross‐sectional areas of the main‐shoot nodal roots decreased under water deficit, but increased in the tiller nodal roots. Root xylem density and arrested nodal roots increased under water deficit, with the formation of root suberization/lignification and large cortical aerenchyma. Genome‐wide association study implicated 11 QTL intervals in the architectural and anatomical nodal root response to water deficit. Among them, three and four QTL intervals had strong effects across seasons and on both root architectural and anatomical traits, respectively. Genome‐wide epistasis analysis revealed 44 epistatically interacting SNP loci. Further analyses showed that these QTL intervals contain important candidate genes, including ZIFL2, MATE, and PPIB, whose functions are shown to be related to the root adaptive response to water deprivation in plants. These results give novel insight into the genetic architectures of barley nodal root response to soil water deficit stress in the fields, and thus offer useful resources for root‐targeted marker‐assisted selection.

Genetic dissection of bread wheat diversity and identification of adaptive loci in response to elevated tropospheric ozone

“…LD decay rates across A, B, and D genomes were calculated by plotting the r 2 against the genetic distance in bp. A cut off of r 2 = 0.1 was chosen as the critical distance up to which a gene locus extends (Oyiga et al, 2020).…”

Climate-smart crops: key root anatomical traits that confer flooding tolerance

“…stele, cortex, xylem, and aerenchyma, based on an image processing pipeline, and then those regions can be manually validated with the graphical user interface (GUI). RootScan is useful for high-throughput analyses, and it has been applied in GWAS on root anatomical traits in maize and barley (Oyiga et al 2020, Saengwilai et al 2016. Several similar tools with RootScan, such as PHIV-RootCell (Lartaud et al 2015) and RootAnalyzer (Chopin et al 2015), are proposed to analyze root anatomical properties.…”

“…QTL analysis and GWAS, on CSR by using plant species with large genetic diversities are needed. GWAS combined with high-throughput image analyses of root cross-sections was used in maize and barley (Oyiga et al 2020, Saengwilai et al 2016. On the other hand, sorghum may be also useful for the studies on root anatomical traits because the mapping populations and germplasm collections with wide genetic diversity have already undergone QTL mapping and GWAS, respectively (Kajiya-Kanegae et al 2020, Sakamoto et al 2019.…”

Genetics and genomics of root system variation in adaptation to drought stress in cereal crops

“…Narrower root angles may decrease the energy supplied during root penetration into the deeper soil horizons to optimize water uptake under limited rainfall conditions ( Fig. 1 ; Wasson et al , 2012 ; Meister et al , 2014 ; Oyiga et al , 2019 ). Deep rooting in thinner root systems, compared with thick or shallow root systems, has the potential to adjust to the soil components, particularly in the water-limited dry land soils ( Lynch, 2014 ).…”

“…Three to four QTL intervals showed strong effects across growing seasons for both root morphological and anatomical traits in response to water deficit stress ( Fig. 2 ; Supplementary Table S1 ; Oyiga et al , 2019 ).…”