Plant growth and nitrate absorption and assimilation of two sweet potato cultivars with different N tolerances in response to nitrate supply

• Published in: Scientific reports Vol. 14; no. 1; pp. 21286 - 10
• Main Authors: Duan, Wenxue, Wang, Shasha, Zhang, Haiyan, Xie, Beitao, Zhang, Liming
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 12.09.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 631/443; 631/449; Absorption; Anion Transport Proteins - genetics; Anion Transport Proteins - metabolism; Biological assimilation; Cultivars; Gene Expression Regulation, Plant; Gene regulation; Humanities and Social Sciences; Hydroponics; Ipomoea batatas; Ipomoea batatas - genetics; Ipomoea batatas - growth & development; Ipomoea batatas - metabolism; Leaves; multidisciplinary; N distribution; Nitrate reductase; Nitrate Reductase - genetics; Nitrate Reductase - metabolism; Nitrate transporter gene expression; Nitrate Transporters; Nitrates; Nitrates - metabolism; Nitrite reductase; Nitrite Reductases - genetics; Nitrite Reductases - metabolism; Nitrogen - metabolism; NO3 - influx; Plant growth; Plant Leaves - genetics; Plant Leaves - growth & development; Plant Leaves - metabolism; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Roots - genetics; Plant Roots - growth & development; Plant Roots - metabolism; Potatoes; Root growth; Roots; Science; Science (multidisciplinary); NO; Nitrate transporter gene expression; influx; Nitrate reductase; Nitrite reductase; Root growth; N distribution; Shoot weight; NO3 - influx
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-72422-y

In sweet potato, rational nitrogen (N) assimilation and distribution are conducive to inhibiting vine overgrowth. Nitrate (NO 3 - ) is the main N form absorbed by roots, and cultivar is an important factor affecting N utilization. Herein, a hydroponic experiment was conducted that included four NO 3 - concentrations of 0 (N0), 4 (N1), 8 (N2) and 16 (N3) mmol L -1 with two cultivars of Jishu26 (J26, N-sensitive) and Xushu32 (X32, N-tolerant). For J26, with increasing NO 3 - concentrations, the root length and root surface area significantly decreased. However, no significant differences were observed in these parameters for X32. Higher NO 3 - concentrations upregulated the expression levels of the genes that encode nitrate reductase ( NR2 ), nitrite reductase ( NiR2 ) and nitrate transporter ( NRT1.1 ) in roots for both cultivars. The trends in the activities of NR and NiR were subject to regulation of NR2 and NiR2 transcription, respectively. For both cultivars, N2 increased the N accumulated in leaves, growth points and roots. For J26, N3 further increased the N accumulation in these organs. Under higher NO 3 - nutrition, compared with X32, J26 exhibited higher expression levels of the NiR2 , NR2 and NRT1.1 genes, a higher influx NO 3 - rate in roots, and higher activities of NR and NiR in leaves and roots. Conclusively, the regulated effects of NO 3 - supplies on root growth and NO 3 - utilization were more significant for J26. Under high NO 3 - conditions, J26 exhibited higher capacities of NO 3 - absorption and distributed more N in leaves and in growth points, which may contribute to higher growth potential in shoots and more easily cause vine overgrowth.