Can genetic variability for nitrogen metabolism in the developing ear of maize be exploited to improve yield?

Abstract

Summary• Quantitative trait loci (QTLs) for the main steps of nitrogen (N) metabolism in the developing ear of maize (Zea mays L.) and their co-localization with QTLs for kernel yield and putative candidate genes were searched in order to identify chromosomal regions putatively involved in the determination of yield.• During the grain-filling period, the changes in physiological traits were monitored in the cob and in the developing kernels, representative of carbon and N metabolism in the developing ear. The correlations between these physiological traits and traits related to yield were examined and localized with the corresponding QTLs on a genetic map.• Glycine and serine metabolism in developing kernels and the cognate genes appeared to be of major importance for kernel production. The importance of kernel glutamine synthesis in the determination of yield was also confirmed.• The genetic and physiological bases of N metabolism in the developing ear can be studied in an integrated manner by means of a quantitative genetic approach using molecular markers and genomics, and combining agronomic, physiological and correlation studies. Such an approach leads to the identification of possible new regulatory metabolic and developmental networks specific to the ear that may be of major importance for maize productivity.

Assessing the Metabolic Impact of Nitrogen Availability Using a Compartmentalized Maize Leaf Genome-Scale Model

“…These tissuespecific models will follow community (Zomorrodi and Maranas, 2012;Zomorrodi et al, 2014) and multitissue human model (Duarte et al, 2007;Bordbar et al, 2011;Thiele et al, 2013) reconstruction principles. The tissues can be linked using intertissue transport reactions, with the stalk tissue acting as the central transporter among the various tissues and particularly to the developing ear (Cañas et al, 2012). A whole-plant genome-scale model of maize will help to elucidate the flow of N from the root to the other tissues in the plant, from the shoot to the ear, and within the developing ear (Cañas et al, 2010).…”

A genetic relationship between nitrogen use efficiency and seedling root traits in maize as revealed by QTL analysis

“…Recently, mapping quantitative trait loci (QTL) has become a powerful tool to identify genomic regions and even putative candidate genes involved in the genetic variation of complex traits. Many maize QTLs for NUE traits at agronomic and physiological levels have been identified, including traits for NupE and NutE ( Bertin and Gallais, 2000 ; Coque and Gallais 2006 ; Coque et al , 2008 ), N grain uptake ( Coque et al , 2006 ), post-silking N-uptake ( Gallais and Hirel, 2004 ; Coque et al , 2008 ), N remobilization ( Gallais and Hirel, 2004 ; Coque et al , 2006 ; Coque et al , 2008 ), and N metabolism ( Zhang et al , 2010 ; Cañas et al , 2012 ). Likewise, many maize QTLs that regulate RSA have been identified in several linkage populations, and meta-analysis has further determined the putative consensus root-QTL clusters ( Lebreton et al , 1995 ; Landi et al , 2002 ; Tuberosa et al , 2002 , 2003 ; Zhu et al , 2006 ; Liu et al , 2008 ; Hund et al , 2011 ).…”

Food security through translational biology between wheat and rice

“…Genetic variability for nitrogen metabolism in the developing ear of maize has been suggested to improve yields (Cañas et al. ). BNI improves N uptake and NUE due to its inhibitory effects on nitrification (Subbarao et al.…”

“…However, genotypic variation in grain N concentration is low (0.95-1.2; Tirol-Padre et al 1996), therefore, it may not be feasible to improve NUE for grain by reducing grain N concentration using conventional breeding as grain N concentration is affected more by environments than by genotypes (Ladha et al 1998). Genetic variability for nitrogen metabolism in the developing ear of maize has been suggested to improve yields (Cañas et al 2012). BNI improves N uptake and NUE due to its inhibitory effects on nitrification (Subbarao et al 2006).…”