Natural products have long been a crucial source of, or provided inspiration for new agrochemical discovery.  Naturally occurring 18β-glycyrrhetinic acid shows broad-spectrum bioactivities and is a potential skeleton for novel drug discovery.  To extend the utility of 18β-glycyrrhetinic acid for agricultural uses, a series of novel 18β-glycyrrhetinic acid amide derivatives were prepared and evaluated for their antibacterial potency.  Notably, compound 5k showed good antibacterial activity in vitro against Xanthomonas oryzae pv. oryzae (Xoo, EC₅₀=3.64 mg L^–1), and excellent protective activity (54.68%) against Xoo in vivo.  Compound 5k induced excessive production and accumulation of reactive oxygen species in the tested pathogens, resulting in damaging the bacterial cell envelope.  More interestingly, compound 5k could increase the activities of plant defense enzymes including catalase, superoxide dismutase, peroxidase, and phenylalanine ammonia lyase.  Taken together, these enjoyable results suggested that designed compounds derived from 18β-glycyrrhetinic acid showed potential for controlling intractable plant bacterial diseases by disturbing the balance of the phytopathogen’s redox system and activating the plant defense system

Efficient and stable expression of foreign genes in cells and transgenic animals is important for gain-of-function studies and the establishment of bioreactors.  Safe harbor loci in the animal genome enable consistent overexpression of foreign genes, without side effects.  However, relatively few safe harbor loci are available in pigs, a fact which has impeded the development of multi-transgenic pig research.  We report a strategy for efficient transgene knock-in in the endogenous collagen type I alpha 1 chain (COL1A1) gene using the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) system.  After the knock-in of a 2A peptide-green fluorescence protein (2A-GFP) transgene in the last codon of COL1A1 in multiple porcine cells, including porcine kidney epithelial (PK15), porcine embryonic fibroblast (PEF) and porcine intestinal epithelial (IPI-2I) cells, quantitative PCR (qPCR), Western blotting, RNA-seq and CCK8 assay were performed to assess the safety of COL1A1 locus.  The qPCR results showed that the GFP knock-in had no effect (P=0.29, P=0.66 and P=0.20 for PK15, PEF and IPI-2I cells, respectively) on the mRNA expression of COL1A1 gene.  Similarly, no significant differences (P=0.64, P=0.48 and P=0.80 for PK15, PEF and IPI-2I cells, respectively) were found between the GFP knock-in and wild type cells by Western blotting.  RNA-seq results revealed that the transcriptome of GFP knock-in PEF cells had a significant positive correlation (P<2.2e–16) with that of the wild type cells, indicating that the GFP knock-in did not alter the global expression of endogenous genes.  Furthermore, the CCK8 assay showed that the GFP knock-in events had no adverse effects (P_24h=0.31, P_48h=0.96, P_72h=0.24, P_96h=0.17, and P_120h=0.38) on cell proliferation of PK15 cells.  These results indicate that the COL1A1 locus can be used as a safe harbor for foreign genes knock-in into the pig genome and can be broadly applied to farm animal breeding and biomedical model establishment