Probiotics that Ameliorate Cognitive Impairment through Anti-Inflammation and Anti-Oxidation in Mice.

The gut-brain axis encompasses a bidirectional communication pathway between the gastrointestinal microbiota and the central nervous system. There is some evidence to suggest that probiotics may have a positive effect on cognitive function, but more research is needed before any definitive conclusions can be drawn. Inflammation-induced by lipopolysaccharide (LPS) may affect cognitive function. To confirm the effect of probiotics on oxidative stress induced by LPS, the relative expression of antioxidant factors was confirmed, and it was revealed that the administration of probiotics had a positive effect on the expression of antioxidant-related factors. After oral administration of probiotics to mice, an intentional inflammatory response was induced through LPS i.p., and the effect on cognition was confirmed by the Morris water maze test, nitric oxide (NO) assay, and interleukin (IL)-1ß enzyme-linked immunosorbent assay performed. Experimental results, levels of NO and IL-1 ß in the blood of LPS i.p. mice were significantly decreased, and cognitive evaluation using the Morris water maze test showed significant values in the latency and target quadrant percentages in the group that received probiotics. This proves that intake of these probiotics improves cognitive impairment and memory loss through anti-inflammatory and antioxidant mechanisms.

Effect of Bacillus aryabhattai H26-2 and B. siamensis H30-3 on Growth Promotion and Alleviation of Heat and Drought Stresses in Chinese Cabbage.

Plants are exposed to biotic stresses caused by pathogen attack and complex abiotic stresses including heat and drought by dynamic climate changes. To alleviate these stresses, we investigated two bacterial stains, H26-2 and H30-3 in two cultivars ('Ryeokkwang' and 'Buram-3-ho') of Chinese cabbage in plastic pots in a greenhouse. We evaluated effects of bacterial strains on plant growth-promotion and mitigation of heat and drought stresses; the role of exopolysaccharides as one of bacterial determinants on alleviating stresses; biocontrol activity against soft rot caused by Pectobacterium carotovorum subsp. carotovorum PCC21. Strains H26-2 and H30-3 significantly increased fresh weights compared to a MgSO4 solution; reduced leaf wilting and promoted recovery after re-watering under heat and drought stresses. Chinese cabbages treated with H26-2 and H30-3 increased leaf abscisic acid (ABA) content and reduced stomatal opening after stresses treatments, in addition, these strains stably colonized and maintained their populations in rhizosphere during heat and drought stresses. As well as tested bacterial cells, exopolysaccharides (EPS) of H30-3 could be one of bacterial determinants for alleviation of tested stresses in Chinese cabbages, however, the effects were different to cultivars of Chinese cabbages. In addition to bacterial activity to abiotic stresses, H30-3 could suppress incidence (%) of soft rot in 'Buram-3-ho'. The tested strains were identified as Bacillus aryabhattai H26-2 and B. siamensis H30-3 based on 16S rRNA gene sequence analysis. Taken together, H26-2 and H30-3 could be candidates for both plant growth promotion and mitigation of heat and drought stresses in Chinese cabbage.

Loss of Arabidopsis Halotolerance 2-like (AHL), a 3'-phosphoadenosine-5'-phosphate phosphatase, suppresses insensitive response of Arabidopsis thaliana ring zinc finger 1 (atrzf1) mutant to abiotic stress.

KEY MESSAGE: Destruction of PAP phosphatase AHL suppresses atrzf1 phenotype in abiotic stress responses. AHL plays an intermediate role in the regulation of proline accumulation by PAP nucleotidase. Proline (Pro) metabolism is important for environmental responses, plant development, and growth. However, the role of Pro in abiotic stress process is unclear. Using atrzf1 (Arabidopsis thaliana ring zinc finger 1) mutant as a parental line for T-DNA tagging mutagenesis, we identified a suppressor mutant designated as proline content alterative 17 (pca17) that suppressed insensitivity of atrzf1 to abiotic stresses during early seedling growth. Pro content of pca17 was lower than that in both wild type (WT) and atrzf1 while complementary lines were less sensitive to abscisic acid (ABA) and abiotic stresses compared to WT. Thermal Asymmetric Interlaced (TAIL)-PCR of pca17 showed that T-DNA was inserted at site of At5g54390 (AHL for Arabidopsis Halotolerance 2-like) encoding 3'-phosphoadenosine-5'-phosphate (PAP) phosphatase. Under drought stress condition, products of sulfate metabolism such as PAP and adenosine monophosphate were significantly lower in pca17 than those in WT and atrzf1. Furthermore, pca17 showed significantly higher levels of several important drought parameters including malondialdehyde, ion leakage, and water loss than WT and atrzf1. Fluorescence signal of green fluorescent protein (GFP)-tagged AHL was quite strong in nuclei of the root and guard cells of transgenic seedlings. Additionally, AHL promoter-ß-glucuronidase (GUS) construct revealed substantial gene expression in vasculature tissues and pollen. Collectively, these findings demonstrate that pca17 acts as a dominant suppressor mutant of atrzf1 in abiotic stress response by modulating proline and sulfate metabolism.

Aspergillus terreus JF27 Promotes the Growth of Tomato Plants and Induces Resistance against Pseudomonas syringae pv. tomato.

Certain beneficial microorganisms isolated from rhizosphere soil promote plant growth and induce resistance to a wide variety of plant pathogens. We obtained 49 fungal isolates from the rhizosphere soil of paprika plants, and selected 18 of these isolates that did not inhibit tomato seed germination for further investigation. Based on a seed germination assay, we selected four isolates for further plant tests. Treatment of seeds with isolate JF27 promoted plant growth in pot tests, and suppressed bacterial speck disease caused by Pseudomonas syringae pathovar (pv.) tomato DC3000. Furthermore, expression of the pathogenesis-related 1 (PR1) gene was higher in the leaves of tomato plants grown from seeds treated with JF27; expression remained at a consistently higher level than in the control plants for 12 h after pathogen infection. The phylogenetic analysis of a partial internal transcribed spacer sequence and the ß-tubulin gene identified isolate JF27 as Aspergillus terreus. Taken together, these results suggest that A. terreus JF27 has potential as a growth promoter and could be used to control bacterial speck disease by inducing resistance in tomato plants.