Rice varieties with contrasting nitrogen use efficiency present different expression of amino acid transporters and ammonium transporters

ABSTRACT

We evaluated the effects of isoforms of ammonium transporters (AMT) and amino acid transporters (AAT) on three rice varieties cultivated with different levels of ammonium (NH₄⁺) and its biochemical responses. The rice varieties used were IAC-47 (improved), Manteiga and Piauí (landraces), cultivated under 0.2 mM NH₄⁺ (low N, LN), 1 mM NH₄⁺ (sufficient N, SN) or resupply with 1 mM of NH₄⁺ after three days without nitrogen (N). When cultivated with LN, the Piauí variety presented a higher expression of AAT (Lysine-Histidine Transporter 4 (OsLHT4) and GABA Transporters (OsGAT1)) in roots, while Manteiga and IAC-47 presented higher expression of the Amino Acid Permease 1 (OsAAP1) and Ammonium Transporter 1.1 (OsAMT1.1), respectively. Additionally, Piauí had the higher expression of glutamine synthetase (OsGS1.1 and OsGS1.3) in shoots cultivated with LN or resupply. The Piauí variety displayed higher glutamine synthetase activity and amino acid content under resupply. Manteiga and Piauí presented a lower reduction in fresh weight of leaves and sheaths under LN compared to IAC-47. The results suggest that the improved variety IAC-47 is more efficient when cultivated with SN, while, under LN or resupply, the landrace varieties were superior. Overall, the molecular responses were different among the varieties, which may affected their nitrogen metabolism.

KEYWORDS:

• Landrace
• amino acids
• ammonium
• nitrogen
• metabolism

Acknowledgements

We would like to thank the financial support provided by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and the Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/03650340.2022.2080198

Additional information

Funding

This work was supported by the Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro