Relationship of Nitrogen Use Efficiency with the Activities of Enzymes Involved in Nitrogen Uptake and Assimilation of Finger Millet Genotypes Grown under Different Nitrogen Inputs

Nidhi Gupta,Atul K Gupta,Vikram S Gaur,Anil Kumar

doi:10.1100/2012/625731

Nidhi Gupta, Atul K Gupta + Show 2 more

Open Access

https://doi.org/10.1100/2012/625731

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Abstract

Nitrogen responsiveness of three-finger millet genotypes (differing in their seed coat colour) PRM-1 (brown), PRM-701 (golden), and PRM-801 (white) grown under different nitrogen doses was determined by analyzing the growth, yield parameters and activities of nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase; GOGAT, and glutamate dehydrogenase (GDH) at different developmental stages. High nitrogen use efficiency and nitrogen utilization efficiency were observed in PRM-1 genotype, whereas high nitrogen uptake efficiency was observed in PRM-801 genotype. At grain filling nitrogen uptake efficiency in PRM-1 negatively correlated with NR, GS, GOGAT activities whereas it was positively correlated in PRM-701 and PRM-801, however, GDH showed a negative correlation. Growth and yield parameters indicated that PRM-1 responds well at high nitrogen conditions while PRM-701 and PRM-801 respond well at normal and low nitrogen conditions respectively. The study indicates that PRM-1 is high nitrogen responsive and has high nitrogen use efficiency, whereas golden PRM-701 and white PRM-801 are low nitrogen responsive genotypes and have low nitrogen use efficiency. However, the crude grain protein content was higher in PRM-801 genotype followed by PRM-701 and PRM-1, indicating negative correlation of nitrogen use efficiency with source to sink relationship in terms of seed protein content.

Highlights

Cereal grains are considered to be one of the most important sources of dietary proteins, carbohydrates, vitamins, minerals, and fiber for people all over the world
Attempts were made to understand the mechanisms associated with Nitrogen use efficiency (NUE) and the nitrogen uptake and assimilatory enzymes in finger millet grown under different nitrogen conditions
There was variation in the heading dates within these finger millet genotypes, that is, the heading date for brown (PRM1) genotype ranged from 77 to 85 days, whereas for golden (PRM-701) and white (PRM-801) genotypes ranged from 119 to 130 days. This indicates that brown (PRM-1) genotype is early flowering and golden (PRM-701) and white

Summary

Introduction

Cereal grains are considered to be one of the most important sources of dietary proteins, carbohydrates, vitamins, minerals, and fiber for people all over the world. The role of GDH in N management and recycling has recently been reviewed in a number of whole-plant physiological studies performed on tobacco [12] and maize [13] Since, from both economical and ecological point of view, agricultural practices are going towards extensive systems using lower N fertilizers, a better knowledge of physiological basis of nitrogen use efficiency (NUE) in economically important crop such as finger millet is required. The development of finger millet that can make the best use of N in low-nitrogen soils is essential for the sustainability of agriculture [14] This highly complex objective requires a deep understanding of the physiological and biochemical responses of finger millet genotypes to different nitrogen levels. Attempts were made to understand the mechanisms associated with NUE and the nitrogen uptake and assimilatory enzymes in finger millet grown under different nitrogen conditions

Material and Methods

Results and Discussion

18 Vegetative Flowering Grain filling