Synergy between a shallow root system with a DRO1 homologue and localized P application improves P uptake of lowland rice

Aung Zaw Oo,Tomohiro Nishigaki,Mana Mukai,Yasuhiro Tsujimoto,Yusaku Uga,Toshiyuki Takai

doi:10.1038/s41598-021-89129-z

Abstract

Improved phosphorus (P) use efficiency for crop production is needed, given the depletion of 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 plant base of the soil surface layer where the qsor1-NIL had the greatest root biomass and root surface area despite no genotyipic differences in total values, whereby 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.

Highlights

Improved phosphorus (P) use efficiency for crop production is needed, given the depletion of phosphorus ore deposits, and increasing ecological concerns about its excessive use
Changes in root system architecture (RSA) such as the development of surface roots is another root function to adapt to P deficiency, that is called ‘topsoil foraging’, because P is most available in surface soil layers[9]
We aimed to identify the combination effect by using near-isogenic lines (NILs) of DRO1, and its homologue, the major quantitative trait loci (QTL) of rice controlling root growth angle (RGA)

Summary

Introduction

Improved phosphorus (P) use efficiency for crop production is needed, given the depletion of phosphorus ore deposits, and increasing ecological concerns about its excessive use. 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. Given the finite nature of the P fertilizer resource and increasing ecological concerns about the excess use of P in agricultural systems[2,3,4], it is vital to investigate sustainable crop production strategies that facilitate the efficient utilization of applied and available P in soils Such strategies are critical for the food security of resource-poor farmers with low fertilizer inputs in developing c ountries[5]. The use of P-dipping is currently being tested by hundreds of smallholder farmers in Madagascar

Objectives

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Conclusion