NH787 EMS mutant of rice variety Nagina22 exhibits higher phosphate use efficiency

Yugandhar Poli,Ajay Jain,Veronica Nallamothu,Satendra K Mangrauthia,Ai Hao,Subrahmanyam Desiraju,Muddapuram Deeksha Goud,Xiaowen Wang

doi:10.1038/s41598-021-88419-w

Abstract

Rice (Oryza sativa L.), a major dietary source, is often cultivated in soils poor in available inorganic orthophosphate (Pi), which is a key nutrient for growth and development. Poor soils are amended by phosphorus (P) fertilizer, which is derived from the non-renewable rock phosphate reserves. Therefore, there is a need for developing rice varieties with high productivity under low P conditions. At the ICAR-IIRR, ethyl methanesulfonate (EMS) mutagenized rice genotype Nagina22 (N22) were screened for high grain yield in Pi-deprived soil, which led to the identification of ~ 10 gain-of-function mutants including NH787. Here, detailed comparative morphophysiological, biochemical, and molecular analyses of N22 and NH787 were carried out in hydroponics and potting soil under different Pi regimes. Under Pi-deprived condition, compared with N22, NH787 exhibited higher root and vegetative biomass, the number of tillers, and grain yield. The augmented agronomic traits of NH787 were corroborated with significantly higher photosynthetic rate, pollen fertility, stigma receptivity, and the activities of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT). Further, several genes involved in the maintenance of Pi homeostasis (GPH) were differentially regulated. The study thus revealed a wide-spectrum influence of the mutation in NH787 that contributed towards its higher Pi use efficiency (PUE).

Highlights

Rice (Oryza sativa L.), a major dietary source, is often cultivated in soils poor in available inorganic orthophosphate (Pi), which is a key nutrient for growth and development
In the model plant Arabidopsis thaliana the selection of uniformly grown seedlings with primary root length in the range of ~ 1.5 to 2.5 cm was recommended to minimize the effect of intrinsic variability on the subsequent treatments under different Pi regimes[66,67,68]
The number of lateral roots (NLR) was significantly reduced (47.31%) in NH787 compared with N22 under P+ condition (Fig. S2A,B) but was comparable under P− condition

Summary

Introduction

Rice (Oryza sativa L.), a major dietary source, is often cultivated in soils poor in available inorganic orthophosphate (Pi), which is a key nutrient for growth and development. At the ICAR-IIRR, ethyl methanesulfonate (EMS) mutagenized rice genotype Nagina[22] (N22) were screened for high grain yield in Pi-deprived soil, which led to the identification of ~ 10 gain-of-function mutants including NH787. Functional characterization of several GPH by reverse and/or forward genetic approach has led to the identification of several key positive and negative regulators of sensing and signaling cascades governing the maintenance of Pi homeostasis[3,6,28] (Table 2). EMS-induced mutagenesis is an attractive strategy for inducing genetic variations in the genome[37,38] and has facilitated the development of a rich repository of rice mutants that exhibit tolerance to different biotic and/or abiotic s tresses[39].

Methods

Results

Conclusion