Genomics Approaches for Improving Nitrogen Use Efficiency in Potato

Increasing global food production to feed rapidly growing populations where cultivable land area is limited is a serious challenge. Moreover, increasing production costs, with high fertilizer input costs, particularly using nitrogen (N), and degrading soil health are the major concerns when enhancing the sustainable agricultural food production. Potato, being the major non-cereal food crop globally, is a heavy N fertilizer feeder crop. In the past several agricultural best management practices have been discussed regarding N management in potato crop production through the intervention of agronomy and soil science. However, unlike the advances in other model plants and cereals, the application of molecular genomics tools is lacking in potato, hence it is not possible to enhance plant genetic potential with better nitrogen use efficiency (NUE). Better N-use efficient plants can be grown with less fertilizer input and also on poor soil. This chapter highlights the application of novel genomics tools to improve NUE in potato through the discovery of novel genes and markers for applications in molecular breeding methods and gene manipulation (transgenic) techniques

Physiological and genome-wide RNA-sequencing analyses identify candidate genes in a nitrogen-use efficient potato cv. Kufri Gaurav

Nitrogen (N) is an important nutrient for plant growth. However, its excess application leads to environmental damage. Hence, improving nitrogen use efficiency (NUE) of plant is one of the plausible options to solve the problems. Aim of this study was to identify candidate genes involved in enhancing NUE in potato cv. Kufri Gaurav (N efficient). Plants were grown in aeroponic with two contrasting N regimes (low N: 0.75 mM, and high N: 7.5 mM). Higher NUE in Kufri Gaurav was observed in low N based on the parameters like NUE, NUpE (N uptake efficiency), NUtE (N utilization efficiency) and AgNUE (agronomic NUE). Further, global gene expression profiles in root, leaf and stolon tissues were analyzed by RNA-sequencing using Ion Proton™ System. Quality data (≥Q20) of 2.04–2.73 Gb per sample were mapped with the potato genome. Statistically significant (P ≤ 0.05) differentially expressed genes (DEGs) were identified such as 176 (up-regulated) and 30 (down-regulated) in leaves, 39 (up-regulated) and 105 (down-regulated) in roots, and 81 (up-regulated) and 694 (down-regulated) in stolons. The gene ontology (GO) terms like metabolic process, cellular process and catalytic activity were predominant. Our RT-qPCR analysis confirmed the gene expression profiles of RNA-seq. Overall, we identified candidate genes associated with improving NUE such as superoxide dismutase, GDSL esterase lipase, probable phosphatase 2C, high affinity nitrate transporters, sugar transporter, proline rich proteins, transcription factors (VQ motif, SPX domain, bHLH) etc. Our findings suggest that these candidate genes probably play crucial roles in enhancing NUE in potato. •Agro-physiological study validated a nitrogen use efficient potato cv. Kufri Gaurav in aeroponic.•RNA-sequencing analysis identified candidate genes involved in nitrogen use efficiency in potato cv. Kufri Gaurav.•The candidate genes were superoxide dismutase, probable phosphatase 2C, high affinity nitrate transporters etc