SummarySoluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) mediate cellular membrane fusion and intracellular vesicle trafficking in eukaryotic cells, and are critical in the growth and development of pathogenic fungi such as Magnaporthe oryzae which causes rice blast. Rice blast is thought to involve distinct SNARE-mediated transport and secretion of fungal effector proteins into the host to modulate rice immunity.We have previously characterized two SNARE proteins, secretory protein (MoSec22) and vesicle-associated membrane protein (MoVam7), as being important in cellular transport and pathogenicity. Here, we show that syntaxin 8 (MoSyn8), a Qc-SNARE protein homolog, also plays important roles in growth, conidiation, and pathogenicity.The MoSYN8 deletion mutant (ΔMosyn8) mutant exhibits defects in endocytosis and Factin organization, appressorium turgor pressure generation, and host penetration. In addition, the ΔMosyn8 mutant cannot elaborate biotrophic invasion of the susceptible rice host, or secrete avirulence factors Avr-Pia (corresponding to the rice resistance gene Pia) and Avrpiz-t (the cognate Avr gene for the resistance gene Piz-t) proteins.Our study of MoSyn8 advances our understanding of SNARE proteins in effector secretion which underlies the normal physiology and pathogenicity of M. oryzae, and it sheds new light on the mechanism of the blight disease caused by M. oryzae.

Hypertension is a major global health issue which elevates the risk of a large world population to chronic life-threatening diseases. The inhibition of angiotensin-converting enzyme (ACE) is an effective target to manage essential hypertension. In this study, the fermentation properties (titratable acidity, free amino nitrogen, and fermentation time) and ACE-inhibitory (ACEI) activity of fermented milks produced by 259 Lactobacillus helveticus strains previously isolated from traditional Chinese and Mongolian fermented foods were determined. Among them, 37 strains had an ACEI activity of over 50%. The concentrations of the antihypertensive peptides, Ile-Pro-Pro and Val-Pro-Pro, were further determined by ultra performance liquid chromatography with quadrupole-time-of-flight mass spectrometry. The change of ACEI activity of the fermented milks of 3 strains exhibiting the highest ACEI activity upon gastrointestinal protease treatment was assayed. Fermented milks produced by strain H9 (IMAU60208) had the highest in vitro ACEI activity (86.4 ± 1.5%), relatively short fermentation time (7.5 h), and detectable Val-Pro-Pro (2.409 ± 0.229 µM) and Ile-Pro-Pro (1.612 ± 0.114 µM) concentrations. Compared with the control, a single oral dose of H9-fermented milk significantly attenuated the systolic, diastolic, and mean blood pressure of spontaneously hypertensive rats (SHR) by 15 to 18 mmHg during the 6 to 12 h after treatment. The long-term daily H9-fermented milk intake over 7 wk exerted significant antihypertensive effect to SHR, but not normotensive rats, and the systolic and diastolic blood pressure were significantly lower, by 12 and 10 mmHg, respectively, compared with the control receiving saline. The feeding of H9-fermented milk to SHR resulted in a significantly higher weight gain at wk 7 compared with groups receiving saline, commercial yogurt, and captopril. Our study identified a novel probiotic L. helveticus strain originated from kurut sampled from Tibet (China), which is a valuable resource for future development of functional foods for hypertension management.

Macroautophagy/autophagy is critical for normal appressorium formation and pathogenicity of the rice blast fungus Magnaporthe oryzae, but the molecular base of autophagy linked to pathogenicity remains elusive in this or other pathogenic fungi. We found that MoHat1, a histone acetyltransferase (HAT) homolog, had a role in the regulation of autophagy through the acetylation of autophagy related proteins MoAtg3 and MoAtg9. We also found that MoHat1 was subject to regulation by the protein kinase MoGsk1 that modulated the translocation of MoHat1 from the nucleus to the cytoplasm with the assistance of MoSsb1, a protein chaperone. The alternation of intracellular location affected MoHat1 in the modification of cytosolic autophagy proteins that maintained normal autophagy. Furthermore, we provided evidence linking acetylation of MoAtg3 and MoAtg9 by MoHat1 to functional appressorium development and pathogenicity. Together with the first report of MoAtg9 being subject to acetylation regulation by MoHat1, our studies depicted how MoHat1 regulated autophagy in conjunction with MoGsk1 and how normal autophagy was linked to appressorium formation and function and pathogenicity of M. oryzae.

A total of 154 non-duplicate Salmonella isolates were recovered from 1,105 rectal swabs collected from three large-scale chicken farms (78/325, 24.0%), three large-scale duck farms (56/600, 9.3%) and three large-scale pig farms (20/180, 11.1%) between April and July 2016. Seven serotypes were identified among the 154 isolates, with the most common serotype in chickens and ducks being Salmonella enteritidis and in pigs Salmonella typhimurium. Antimicrobial susceptibility testing revealed that high antimicrobial resistance rates were observed for tetracycline (72.0%) and ampicillin (69.4%) in all sources. Class 1 integrons were detected in 16.9% (26/154) of these isolates and contained gene cassettes aadA2, aadA1, drfA1-aadA1, drfA12-aadA2, and drfA17-aadA5. Three β-lactamase genes were detected among the 154 isolates, and most of the isolates carried blaTEM−1(55/154), followed by blaPSE−1(14/154) and blaCTX−M−55 (11/154). Three plasmid-mediated quinolone resistance genes were detected among the 154 isolates, and most of the isolates carried qnrA (113/154), followed by qnrB (99/154) and qnrS (10/154). Fifty-four isolates carried floR among the 154 isolates. Multilocus sequence typing (MLST) analysis showed that nine sequence types (STs) were identified; ST11 was the most frequent genotype in chickens and ducks, and ST19 was identified in pigs. Our findings indicated that Salmonella was widespread, and the overuse of antibiotics in animals should be reduced considerably in developing countries.