Synergy Between a Shallow Root System With a DRO1 Homologue and Localized P Application Improves Rice P Uptake 

Abstract

Improved phosphorus (P) use efficiency for crop production is needed given the depleting phosphorus ore deposits and increasing ecological concerns about its excessive use. Root system architecture (RSA) is important in efficiently capturing immobile P in soils, while agronomically, localized P application near the roots is a potential approach to address this issue. However, the interaction between genetic traits of RSA and localized P application has been little understood. Near-isogenic lines (NILs) and their parent of rice (qsor1-NIL, Dro1-NIL, and IR64, with shallow, deep, and intermediate root growth angles (RGA), respectively) were grown in flooded pots after placing P near the roots at transplanting (P-dipping). The experiment identified that the P-dipping created an available P hotspot at the soil surface; the qsor1-NIL had the greatest root biomass and root surface area in the 0–3 cm soil layer despite no genotype differences in total values; the qsor1-NIL had significantly greater biomass and P uptake than the other genotypes in the P-dipping. The superior surface root development of qsor1-NIL could have facilitated P uptakes from the P hotspot, implying that P-use efficiency in crop production can be further increased by combining genetic traits of RSA and localized P application.

Transcriptome profiles of rice roots under simulated microgravity conditions and following gravistimulation

“…A functional allele of DRO1 causes deep-rooting and enhances the ability of drought avoidance (Uga et al, 2013). A non-functional allele of quantitative trait locus for SOIL SURFACE ROOTING 1 (qSOR1) causes shallow-rooting and these roots are more effective for surface layer phosphorus absorption (Kitomi et al, 2020;Oo et al, 2021). Thus, genetic improvement of the root growth angle by manipulating root gravitropism contributes to the enhanced absorption of water and nutrients in the soil.…”