Disruption of Amino Acid Transporter OsAAP1 Impairs Rice Seedling Establishment and Nitrate Uptake and Assimilation

• Published in: Journal of plant growth regulation Vol. 43; no. 8; pp. 2841 - 2854
• Main Authors: Pereira, Erinaldo Gomes, Santos, Leandro Azevedo, Chapeta, Ana Carolina Oliveira, de Souza Ribeiro, Yrexam Rodrigues, Santa-Catarina, Claudete, Bucher, Cassia Pereira Coelho, Bucher, Carlos Alberto, García, Andrés Calderín, Fernandes, Manlio Silvestre
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.08.2024; Springer Nature B.V
• Subjects: Absorption; Agriculture; Amino acid sequence; Amino acids; Aquatic plants; Assimilation; Biological assimilation; Biomedical and Life Sciences; Crop development; Gene expression; Geographical distribution; Life Sciences; Metabolism; Nitrates; Nitrogen; Plant Anatomy/Development; Plant Physiology; Plant Sciences; Plant species; Rice; Ripening; Seedlings; Amino acids; Nitrogen; Metabolism; Amino acid permeases; Rice
• ISSN: 0721-7595; 1435-8107
• DOI: 10.1007/s00344-024-11312-z

Nitrogen (N) is an essential nutrient for plants. Nitrate is often the main inorganic N form absorbed, and amino acids are the predominant organic N form transported in most plant species. Amino acid transporters (AATs) mediate the distribution of amino acids between organs, and any disturbance in this process can cause changes in crop development. To date, the OsAAP1 amino acid transporter has been characterized in the most detail during the reproductive and ripening periods in rice plants. In this study, we identified the sites of OsAAP1 expression during the early stages of rice development and determined the implications of OsAAP1 knockout on seedling establishment, nitrate–N uptake and assimilation, and the expression of genes related to N and carbon (C) metabolism. OsAAP1 is strongly expressed in the coleorhiza, radicle, and epicotyl of seedlings and in the regions of the vascular bundles of roots and leaves. OsAAP1 knockout hindered rice seedling establishment and impaired nitrate absorption. Under low N, OsAAP1 knockout results in damage to NO 3 − absorption, with negative effects on N assimilation and C metabolism. Under sufficient N, nitrate absorption was more strongly impaired, and downregulation of nitrate transporters and N assimilation enzymes was observed. Taken together, the data suggest that the OsAAP1 gene is essential for the early development of rice when nitrate is the predominant N source.