Application of COF nanomaterial carrier in root disease control and its role in plants. Nicotiana tabacum

With the rapid development of nanotechnology, it has been widely penetrated into various fields, and the application of nanocarriers in drug delivery systems is becoming more and more mature. In this study, soil rhizosphere disease (root rot) was taken as the research object, and chemical pesticides were delivered by nanocarriers to achieve efficient control effect. Through the combination of COF carrier and fluomycetin, a highly effective fungicide against pathogenic bacteria of root rot disease (COF@FLU) was successfully constructed. The particle diameter of COF@FLIU was *, the encapsulation rate of active ingredients was *, and the antibacterial rate was 45.3% higher than that of free FLU, but COF itself had no antibacterial activity. Compared with the control group, the plant height, leaf area, root length, antioxidant enzymes and reactive oxygen species were increased by 34%, 54%, 27%, 66% and 52% respectively. The transcriptome found that COF vector induced gene expression changes in plants. These genes are mainly enriched in MAPK signaling pathway involved in cell proliferation and differentiation, Carbon fixation in photosynthetic organisms pathway that maintains carbon cycle and improves photosynthesis, and Plant that regulates growth and development hormone signal transduction pathway, etc. According to the metabolome, the differential abundance of metabolites in plants induced by COF was mainly enriched in Cysteine and methionine metabolism, which is involved in protein synthesis and antioxidant defense, and Lipoic acid metabolism, which is related to energy metabolism. And enzyme catalyzed Biosynthesis of cofactors. Combined transcriptome and metabolome analysis further revealed that COF can regulate photomorphogenesis and environmental adaptation, thereby promoting plant growth. This study proved the high efficiency of COF nanocarriers in soil rhizosphere disease control, and also provided a scientific basis for the application of COF in plant growth regulation.