Varietal responses of root characteristics to low nitrogen application explain the differing nitrogen uptake and grain yield in two rice varieties

Frontiers in Plant Science

Plant Science

Lei Liu¹  Kehui Cui¹  Jianliang Huang¹  Xiaoli Qi¹  Shaobing Peng¹  Yu Wu¹ 

[1] National Key Laboratory of Crop Genetic Improvement, Wuhan, Hubei, China;Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan, Hubei, China;College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China;

关键词: apoplasmic pathway;    ammonium transporter genes;    lignification;    low nitrogen application rate;    nitrogen uptake;    Oryza sativa;    root characteristics;   

DOI  :  10.3389/fpls.2023.1244281

 received in 2023-06-22, accepted in 2023-07-18,  发布年份 2023

来源: Frontiers

【 摘 要 】

Rice rootcharacteristics are tightly associated with high-efficient nitrogen uptake. To understand the relationship of root plastic responses with nitrogen uptake when reducing nitrogen application for green rice production, a hydroponic experiment and a soil pot experiment were conducted under high (HN) and low (LN) nitrogen applications, using two rice (Oryza sativa L.) varieties, NK57 and YD6, three nitrogen absorption traits (total nitrogen accumulation, net NH4+ influx on root surface, nitrogen uptake via apoplasmic pathway) and root characteristics were investigated. In comparison with HN, LN significantly reduced nitrogen absorption and grain yield in both varieties. Concomitantly, there was a decrease in total root length, root surface area, root number, root volume, and root cortical area under LN, while single root length, root aerenchyma area, and root lignin content increased. The expression of OsAMT1;1 and OsAMT1;2 down-regulated in both varieties. The findings revealed that YD6 had smaller reduction degree for the three nitrogen absorption traits and grain yield, accompanied by smaller reduction degree in total root length, root surface area, root cortical area, and expression of the two genes under LN. These root characteristics were significantly and positively correlated with the three nitrogen absorption traits and grain yield, especially under LN. These results indicate that a large root system, lower reduction degree in several root characters, and high expression of OsAMT genes in YD6 explains its high nitrogen accumulation and grain yield under reduced nitrogen application. The study may provide rationale for developing varieties with low nitrogen fertilizer requirements for enabling green rice production.

【 授权许可】

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Copyright © 2023 Liu, Cui, Qi, Wu, Huang and Peng