This study investigated the effect of Bacillus subtilis DSM 29784 (Ba) and enzymes (xylanase and β-glucanases; Enz), alone or in combination (BE) as antibiotic replacements, on the growth performance, digestive enzyme activity, immune response, and intestinal barrier of broiler chickens. In total, 1200 1-d-old broilers were randomly assigned to five dietary treatments, each with six replicate pens of 40 birds for 63 d as follows: A) basal diet (control), supplemented with B) 1×109 colony-forming units (cfu)/kg Ba, C) 300 mg/kg Enz, D) 1×109 cfu/kg Ba and 300 mg/kg Enz, and E) 250 mg/kg enramycin (ER). Ba, Enz, and BE, similar to ER, decreased the feed conversion rate, maintained intestinal integrity with a higher villus height-to-crypt depth ratio, and increased the numbers of goblet cells. The BE group exhibited higher expression of claudin-1 and Mucin-2 than the other four groups. BE supplementation significantly increased the α-diversity and β-diversity of the intestinal microbiota and markedly enhanced lipase activity in the duodenal mucosa. Serum endotoxin was significantly decreased in the BE group. Compared to those in the control group, increased superoxide dismutase and glutathione peroxidase activities were observed in the jejunal mucosa of Ba and BE groups, respectively. In conclusion, the results suggested that dietary treatment with Ba, Enz, or BE has beneficial effects on growth performance and anti-oxidative capacity, and BE had better effects than Ba or Enz alone on digestive enzyme activity and the intestinal microbiota. Ba or Enz could be used as an alternative to antibiotics for broiler chickens.

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Meloidogyne incognita and Meloidogyne graminicola are root-knot nematodes (RKNs) infecting rice (Oryza sativa L.) roots and severely decreasing yield, whose mechanisms of action remain unclear. We investigated RKN invasion and development in rice roots through RNA-seq transcriptome analysis. The results showed that 952 and 647 genes were differently expressed after 6 (invasion stage) and 18 (development stage) days post inoculation, respectively. Gene annotation showed that the differentially expressed genes were classified into diverse metabolic and stress response categories. Furthermore, phytohormone, transcription factor, redox signaling, and defense response pathways were enriched upon RKN infection. RNA-seq validation using qRT-PCR confirmed that CBL-interacting protein kinase (CIPK) genes (CIPK5, 8, 9, 11, 14, 23, 24, and 31) as well as brassinosteroid (BR)-related genes (OsBAK1, OsBRI1, D2, and D11) were altered by RKN infection. Analysis of the CIPK9 mutant and overexpressor indicated that the RKN populations were smaller in cipk9 and larger in CIPK9 OX, while more galls were produced in CIPK9 OX plant roots than the in wild-type roots. Significantly fewer numbers of second-stage infective juveniles (J2s) were observed in the plants expressing the BR biosynthesis gene D2 mutant and the BR receptor BRI1 activation-tagged mutant (bri1-D), and fewer galls were observed in bri1-D roots than in wild-type roots. The roots of plants expressing the regulator of ethylene signaling ERS1 (ethylene response sensor 1) mutant contained higher numbers of J2s and developed more galls compared with wild-type roots, suggesting that these signals function in RKN invasion or development. Our findings broaden our understanding of rice responses to RKN invasion and provide useful information for further research on RKN defense mechanisms.

Heterodera glycines is one of the most destructive pathogens of soybean. Soybean seeds coated with Bacillus simplex Sneb545 have shown resistance to H. glycines as a result of induced systemic resistance (ISR) in the plants. In this study, we aimed to identify the resistance-inducing determinants from this B. simplex strain. Combining the ISR bioassay, six ISR-active compounds were isolated from a culture of B. simplex Sneb545 using organic solvent gradient extraction, silica gel column chromatography, Sephadex LH-20 column chromatography, and semi-preparative high-performance liquid chromatography (HPLC), and all systems were based on activity tracking. The compounds were determined as cyclic(Pro-Tyr), cyclic(Val-Pro), cyclic(Leu-Pro), uracil, phenylalanine, and tryptophan using 1 H nMR and 13 C NMR. In plants from seeds coated with Bacillus simplex Sneb545, these six ISRactive compounds delayed the development of H. glycines in soybean roots. Moreover, cyclic(Pro-Tyr), cyclic(Val-Pro), and tryptophan reduced the number of nematodes in soybean roots. The expression levels of defense-related genes with cyclic(Val-Pro), tryptophan and uracil treatment soybean analysed using Quantitative real-time PCR (qRT-PCR). The results indicate cyclic(Val-Pro), tryptophan and uracil induced the expression of defense-related genes involved in the SA-and JA-pathways to against H. glycines. Our research results provide new agents for the control of H. glycines. Soybean is an important economic crop, which is widely used in oil and food production. The United States of America, Brazil, and Argentina are the top three producers of soybean, producing approximately 123.7, 117.0, and 55.0 million metric tons annually, respectively, China is ranked fourth globally, with a production of 15.9 million metric tons per year (https ://soyst ats.com/inter natio nal-world-soybe an-produ ction , 2019). Heterodera glycines (soybean cyst nematode, SCN) is one of the most destructive pathogens of soybean 1. This nematode is a considerable threat to soybean production and is responsible for annual losses of up to USD 1.5 billion globally 2. Chemical nematicides are widely used to control parasitic nematode disease in soybean 3. However, their application not only causes widespread environmental pollution but also threatens human health. In addition, drug tolerance of nematodes has been enhanced by the long-term use of chemical nematicides 4,5. It is necessary, therefore, to seek safe, effective, and environmentally friendly products to defend soybean plants against SCN 6. The life cycle of SCN consists of four juvenile stages (J1-J4). The embryo in the egg develops into the first stage (J1) of juvenile and then molts in the egg to form the infested second-stage juveniles (J2). The J2 penetrates the root of the host plant, once J2 reach the vascular cylinder, they will establish a feeding site at the root, and then begins to develop into the third (J3) and fourth (J4) juvenile stages in the root system. Finally, matures to an adult female or male an...