Fatty acid compositions regulate BDE-153 migration in rice: Influence of biochar-derived organic matter and organic molecule

This study is the first to find the controlling role of key fatty acids from the rice in the accumulation of BDE-153 (PBDE congener with high lipophilicity and bioaccumulative potential) in plant that are affected by the different doses of biochar-derived dissolved organic matter (BDOM) and biochar-derived organic molecule (BOM). Compared with the BDE-153 treatment group, the BDOM/BOM and BDE-153 treatment groups showed an increase in the content of some fatty acids. The result indicates that BDOM/BOM can alleviate the inhibitory effect of BDE-153 on the fatty acid content of rice. In addition, BDOM/BOM reduces the ratio of unsaturated fatty acids (USFA)/saturated fatty acids (SFA), which damages the integrity of the cell membrane and facilitates the uptake of BDE-153. Therefore, BDOM/BOM significantly promoted the uptake of BDE-153 in rice, with the highest increase reaching 273.8 %/120.4 %. Additionally, the content of very-long chain fatty acids (VLFA) and fatty acid with Log K_ow> 11 had stronger correlation (0.9973 and 0.9998) with the BDE-153 contents in rice root under the influence of BDOM. In shoots, the content of medium-long chain fatty acids (MLFA), SFA, C_16:0, C_18:0 and C_18:1 played a significant role in the accumulation of BDE-153, which indicated that the content of these fatty acids significantly affects the enrichment of BDE-153. Under the influence of BOM, fatty acid content had good correlation with BDE-153 content except the fatty acids with Log K_ow between 7 and 8 in root, whereas the SFA, fatty acids other than Log K_ow 10-11, C_16:0 and C_18:0 had quadratic correlation with BDE-153 content in shoot. Thus, different carbon chain, saturation or K_ow of fatty acids played in the key role during the BDE-153 accumulation in rice, which will provide a basis for selecting the biochar that control the pollutant migration into plant.