| Autor: |
Garnett, Trevor, Plett, Darren, Conn, Vanessa, Conn, Simon, Rabie, Huwaida, Antoni Rafalski, J., Dhugga, Kanwarpal, Tester, Mark A., Kaiser, Brent N. |
| Předmět: |
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| Zdroj: |
Frontiers in Plant Science; Nov2015, p1-13, 13p |
| Abstrakt: |
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-) and ammonium (NH+) high-affinity transport systems. 3 4 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. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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