AUTHOR=Gao Jian , Ge Shaohua , Wang Hailong , Fang Yunying , Sun Luming , He Tianyi , Cheng Xiaoyi , Wang Di , Zhou Xuanwei , Cai Heqing , Li Caibin , Liu Yanxiang , E Yang , Meng Jun , Chen Wenfu 

TITLE=Biochar-extracted liquor stimulates nitrogen related gene expression on improving nitrogen utilization in rice seedling

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1131937

DOI=10.3389/fpls.2023.1131937

ISSN=1664-462X

ABSTRACT=<sec><title>Introduction</title><p>Biochar has been shown to be an effective soil amendment for promoting plant growth and improving nitrogen (N) utilization. However, the physiological and molecular mechanisms behind such stimulation remain unclear.</p></sec><sec><title>Methods</title><p>In this study, we investigated whether biochar-extracted liquor including 21 organic molecules enhance the nitrogen use efficiency (NUE) of rice plants using two N forms (NH<sub>4</sub><sup>+</sup>-N and NO<sub>3</sub><sup>-</sup>-N). A hydroponic experiment was conducted, and biochar-extracted liquor (between 1 and 3% by weight) was applied to rice seedlings.</p></sec><sec><title>Results</title><p>The results showed that biochar-extracted liquor significantly improved phenotypic and physiological traits of rice seedlings. Biochar-extracted liquor dramatically upregulated the expression of rice N metabolism-related genes such as <italic>OsAMT1.1</italic>, <italic>OsGS1.1</italic>, and <italic>OsGS2</italic>. Rice seedlings preferentially absorbed NH<sub>4</sub><sup>+</sup>-N than NO<sub>3</sub><sup>-</sup>-N (<italic>p</italic> &lt; 0.05), and the uptake of NH<sub>4</sub><sup>+</sup>-N by rice seedlings was significantly increased by 33.60% under the treatment of biochar-extracted liquor. The results from molecular docking showed that OsAMT1.1protein can theoretically interact with 2-Acetyl-5-methylfuran, trans-2,4-Dimethylthiane, S, S-dioxide, 2,2-Diethylacetamide, and 1,2-Dimethylaziridine in the biochar-extracted liquor. These four organic compounds have similar biological function as the OsAMT1.1 protein ligand in driving NH<sub>4</sub><sup>+</sup>-N uptakes by rice plants.</p></sec><sec><title>Discussion</title><p>This study highlights the importance of biochar-extracted liquor in promoting plant growth and NUE. The use of low doses of biochar-extracted liquor could be an important way to reduce N input in order to achieve the purpose of reducing fertilizer use and increasing efficiency in agricultural production.</p></sec>