TY  - JA
AU  - Garnett,T.
AU  - Plett,D.
AU  - Conn,V.
AU  - Conn,S.
AU  - Rabie,H.
AU  - Rafalski,A.
AU  - Dhugga,K.
AU  - Tester,M.
AU  - Kaiser,B.N.
TI  - Variation for N Uptake System in Maize: Genotypic Response to N Supply
SN  - 1664-462X
PY  - 2015///
CY  - Switzerland
PB  - Frontiers, 
KW  - AGROVOC
KW  - Nitrates
KW  - Nitrogen
KW  - Zea mays
KW  - Ammonium
N1  - Peer review; Open Access
N2  - An understanding of the adaptations made by plants in their nitrogen (N) uptake systems in response to reduced N supply is important to the development of cereals with enhanced N uptake efficiency (NUpE). Twenty seven diverse genotypes of maize (Zea mays, L.) were grown in hydroponics for 3 weeks with limiting or adequate N supply. Genotypic response to N was assessed on the basis of biomass characteristics and the activities of the nitrate (NO−3) and ammonium (NH+4) high-affinity transport systems. Genotypes differed greatly for the ability to maintain biomass with reduced N. Although, the N response in underlying biomass and N transport related characteristics was less than that for biomass, there were clear relationships, most importantly, lines that maintained biomass at reduced N maintained net N uptake with no change in size of the root relative to the shoot. The root uptake capacity for both NO−3 and NH+4 increased with reduced N. Transcript levels of putative NO−3 and NH+4 transporter genes in the root tissue of a subset of the genotypes revealed that predominately ZmNRT2 transcript levels responded to N treatments. The correlation between the ratio of transcripts of ZmNRT2.2 between the two N levels and a genotype's ability to maintain biomass with reduced N suggests a role for these transporters in enhancing NUpE. The observed variation in the ability to capture N at low N provides scope for both improving NUpE in maize and also to better understand the N uptake system in cereals
UR  - https://www.frontiersin.org/articles/10.3389/fpls.2015.00936/full#h7
DO  - https://doi.org/10.3389/fpls.2015.00936
T2  - Frontiers in Plant Science
ER  -