Nitrate Content and Expression of Putative Nitrate Transporter Genes in Lettuce Fertilized with Nitrogen Fertilizers

ABSTRACT

Nitrate accumulation in plants is influenced by environmental conditions and genetic variability. It is important to develop approaches that could be used to reduce nitrate levels in lettuce (Lactuca sativa L.) because nitrate accumulated in leaves can cause harmful health effects in humans. A greenhouse experiment was conducted to determine effects of ammonium nitrate or urea nitrogen on lettuce fresh weight, nitrate content, and characterization of nitrate transporter genes in lettuce. Head fresh weight in cultivars grown with the nitrogen fertilizers differed. All cultivars accumulated more nitrates with urea than with ammonium nitrate fertilizer. ‘Great Lakes’ had lower nitrate accumulation than other cultivars due to urea or ammonium nitrate treatment. Lettuce nitrate transporter genes LsNRT1 and LsNRT2 were detected and their expression level varied due to cultivar and leaf position. ‘Great Lakes’ had low mRNA levels of LsNRT1 and LsNRT2 in leaves compared to other cultivars. ‘Great Lakes’ could be used for lettuce production due to high yield and lower nitrate content.

KEYWORDS:

• Lactuca sativa
• gene expression analysis
• nitrate

Funding

The authors thank the Agricultural Research and Higher Education Institution–IRESA and the Horticultural Sciences Laboratory (LR13AGR01) of INAT for financial support that made this project possible.

Additional information

Funding

The authors thank the Agricultural Research and Higher Education Institution–IRESA and the Horticultural Sciences Laboratory (LR13AGR01) of INAT for financial support that made this project possible.