Plant Nutriomics: A New Frontier of Plant Biology

Authors: Subodh Kumar Sinha*, Basavaprabhu L. Patil, Monika Dalal and Rohini Sreevathsa
National Research Centre on Plant Biotechnology, IARI Campus, Pusa, New Delhi-110012

*Corresponding author:

In the past 50 years there has been a marked increase in food productivity which facilitated a significant decrease in world hunger, despite doubling of the human population. However, in next 50 years it will be challenging to increase crop productivity further in order to meet the food requirement of the growing population, due to a range of issues such as decreasing arable land, increasing water scarcity, rapid global climate change, changing food habits, and the use of biomass for the production of biofuels. During 1960s, Green Revolution contributed enormously towards food security by introducing dwarf wheat and rice varieties. These varieties were developed in such a way that they respond to high chemical fertilizer inputs without lodging. The remarkable increase in crop productivity has resulted in many folds increase of the global use of chemical fertilizers and this is expected to increase further. On one hand, the excessive uses of chemical fertilizers are causing great environmental concern while on the other hand it imposes major economic burden on farmers. The environment concerns together with increasing fertilizer costs are prompting the plant biologists throughout the world to look for more nutrient use efficient crops, that is, crops that have better uptake, utilization and remobilization of the nutrients available to them. In years to come, there will a requirement of high yielding crops in soils with reduced fertilizer applications. This can only be achieved by breeding new crop varieties with enhanced adaptation to low fertility soils. This approach is valid both for soils with over-fertilization in high-input areas and soils of low fertility in low-input areas that are deficient in a number of major nutrients such as nitrogen, phosphorus, potassium and other essential elements, as well as having toxic levels of aluminium, manganese and salt.

Interestingly, numerous studies have indicated substantial genetic differences in nutrient efficiency among crop plants and attempts have been made to breed crop plants that thrive well in low fertility soils. However, these breeding efforts mainly involve simple selection of biomass or yield in the field which is not only costly but also subject to environmental interactions and spatial heterogeneity. Therefore, it is advisable to identify and select specific traits that are directly related to a specific nutrient efficiency. These clearly identified traits could be used for more efficient screening in controlled environments, or tagged with molecular markers and then improved through marker assisted selection or gene transformation.

These useful traits for nutrient efficiency may be associated with altered physiological and biochemical pathways in adaptation to nutrient stress. For instance, in Pi-signaling pathway, the regulatory systems in plants have been well studied, enabling plant scientists to modify some key regulator(s) to enhance the uptake and use efficiency of the nutrient through genetic engineering. However, systemic mechanisms might be involved in adaptation to nutrient stress at the whole plant level. The fact that many of the molecular and biochemical changes in response to nutrient deficiency occur in synchrony suggests that the genes involved are co-coordinately expressed and share a common regulatory system. Therefore, systematic studies are required to understand the genomic, transcriptomic, proteomic and metabolomic aspects of nutrient efficiency. This area of studies is termed 'plant nutriomics' that has emerged as a new science in plant biology prompting increased attention by scientists all over the world.

Plant nutrition has been defined as a science which deals with acquisition of nutrient elements by plants and the functions of these elements in the various life processes of plants. Plant nutrition deals mainly with the mobilization, uptake and utilization of the most limiting nutrient elements (N, P, K, Ca, Fe, Zn, B, etc.) as well as their effects on plant growth, development, reproduction and adaptability to adverse environments. As far as the overall nutritional performances (efficiency) of these nutrients are concerned, the understanding of network of all component processes such as uptake, utilization, mobilization etc. are very crucial. Towards achieving the overall performance, traditional plant nutrition studies look at nutrient efficiency mainly at the whole-plant level. Although such an approach is useful, yet studies with whole plants cannot provide sufficient insight into the genetic nature and its specific modification of the nutritional processes. Recent progress in plant molecular biology has provided the means to tackle complex plant nutritional problems through genomic, transcriptomic, proteomic and metabolomic approaches. All these approaches, together with phenotypic analyses, will enable us to elucidate the functions and interactions of plant nutrients at the molecular, cellular, organ and whole-plant levels. The concept of plant nutriomics, therefore, is to integrate nutritional functions at various levels (molecular, cellular, organ and whole-plant) with different tools (genomics, transcriptomics, proteomics and metabolomics).

References (if any)

1. Good et al. (2004) Can less yield more? Is reducing nutrient input into the environment
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2. Yan et al. (2006) Plant Nutriomics in China: An Overview. Ann. Bot. 98:473-482.

About Author / Additional Info:
I am Scientist working at NRC on Plant Biotechnology, New Delhi