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In order to effectively prevent and control the disease caused by common tobacco mosaic virus (TMV), a bacterium strain, Z5, resistant to TMV was isolated from soil and was identified as Bacillus velezensis through morphological, physiological, biochemical and molecular biological tests. The culture solution of this bacterium had an in vitro inhibition rate against TMV up to 96.40% and a control effect of 50.43% on TMV in field plot experiments. After the optimization of fermentation condition through a single factor experiment, the optimal medium for strain Z5 was NB medium with glucose and yeast extract as carbon and nitrogen sources respectively, and the optimum conditions were initial pH 7.0, medium volume 100 mL/250mL and fermentation at 28 ° for 60-72 h. Under the optimized condition, the bacterial count increased by 44.38% and the fermentation broth had a stable inhibitory effect against TMV with an inhibition rate of 98.71%. [ABSTRACT FROM AUTHOR]

Summary: Edeines, a group of cationic antimicrobial peptides produced by the soil bacterium Brevibacillus, have broad biological effects, such as antimicrobial, anticancer and immunosuppressive activities. However, the yield of edeines in wild‐type (WT) Brevibacillus is extremely low, and chemical synthesis of edeines is a time‐consuming process. Genetic engineering has proven to be an effective approach to produce antibiotics with high yield. In this study, the edeine biosynthetic gene cluster (ede BGC), which is involved in edeine production, was identified and characterized in Brevibacillus brevis X23. To improve edeine production in B. brevis X23, the ede BGC promoter was replaced with six different promoters, Pmwp, Pspc, PxylA, Pshuttle‐09, Pgrac or P43, through double‐crossover homologous recombination. The new promoters significantly increased the expression of the ede BGC as well as edeine production by 2.9 ± 0.4 to 20.5 ± 1.2‐fold and 3.6 ± 0.1to 8.7 ± 0.7‐fold respectively. The highest yield of edeines (83.6 mg l−1) was obtained in B. brevis X23 with the Pmwp promoter. This study provides a practical approach for producing high yields of edeines in B. brevis. [ABSTRACT FROM AUTHOR]

Summary: RNase P functions either as a catalytic ribonucleoprotein (RNP) or as an RNA‐free polypeptide to catalyse RNA processing, primarily tRNA 5′ maturation. To the growing evidence of non‐canonical roles for RNase P RNP subunits including regulation of chromatin structure and function, we add here a role for the rice RNase P Rpp30 in innate immunity. This protein (encoded by LOC_Os11g01074) was uncovered as the top hit in yeast two‐hybrid assays performed with the rice histone deacetylase HDT701 as bait. We showed that HDT701 and OsRpp30 are localized to the rice nucleus, OsRpp30 expression increased post‐infection by Pyricularia oryzae (syn. Magnaporthe oryzae), and OsRpp30 deacetylation coincided with HDT701 overexpression in vivo. Overexpression of OsRpp30 in transgenic rice increased expression of defence genes and generation of reactive oxygen species after pathogen‐associated molecular pattern elicitor treatment, outcomes that culminated in resistance to a fungal (P. oryzae) and a bacterial (Xanthomonas oryzae pv. oryzae) pathogen. Knockout of OsRpp30 yielded the opposite phenotypes. Moreover, HA‐tagged OsRpp30 co‐purified with RNase P pre‐tRNA cleavage activity. Interestingly, OsRpp30 is conserved in grass crops, including a near‐identical C‐terminal tail that is essential for HDT701 binding and defence regulation. Overall, our results suggest that OsRpp30 plays an important role in rice immune response to pathogens and provides a new approach to generate broad‐spectrum disease‐resistant rice cultivars. [ABSTRACT FROM AUTHOR]