Biological Control of Tomato Bacterial Wilt, Kimchi Cabbage Soft Rot, and Red Pepper Bacterial Leaf Spot UsingPaenibacillus elgiiJCK-5075
FRONTIERS IN PLANT SCIENCE
Authors: Le, Khanh Duy; Kim, Jueun; Yu, Nan Hee; Kim, Bora; Lee, Chul Won; Kim, Jin-Cheol
Abstract
The over and repeated use of chemical bactericides to control plant bacterial diseases has resulted in unwanted effects, such as environmental pollution, residual toxicity, and resistance buildup in bacterial pathogens. Many previous studies have aimed to develop biological control agents to replace chemical bactericides. In this study, the antibacterial efficacy of the fermentation broth ofPaenibacillus elgiiJCK-5075 and its antibacterial compounds were evaluated against plant pathogenic bacteria, using bothin vitroandin vivobioassays. Pelgipeptins (PGPs) A, B, C, and D that were isolated fromP. elgiiJCK-5075 displayed broad-spectrum antibacterial activity against various plant pathogenic bacteria. The fermentation broth ofP. elgiiJCK-5075, at 5-fold dilution, effectively suppressed the development of tomato bacterial wilt, Kimchi cabbage soft rot, and red pepper bacterial leaf spot in pot experiments with control values of 81, 84, and 67%, respectively. PGP-A and C, at 200 mu g/ml, were also found to markedly reduce the development of Kimchi cabbage bacterial soft rot by 75% and tomato bacterial wilt by 83%, respectively, and their disease control efficacy was comparable to that of oxolinic acid with control values of 81 and 85%, respectively. Additionally, the antibacterial activity of PGP-C was found to be directly correlated with membrane damage mechanisms. These results indicates thatP. elgiiJCK-5075 producing PGPs could be used as a biocontrol agent for the control of plant bacterial diseases. This is the first report on thein vitroandin vivoantibacterial activity of PGPs against bacterial plant pathogens.
An isogenic neurovascular unit model comprised of human induced pluripotent stem cell-derived brain microvascular endothelial cells, pericytes, astrocytes, and neurons
FLUIDS AND BARRIERS OF THE CNS
Authors: Canfield, Scott G.; Stebbins, Matthew J.; Faubion, Madeline G.; Gastfriend, Benjamin D.; Palecek, Sean P.; Shusta, Eric V.
Abstract
Background Brain microvascular endothelial cells (BMECs) astrocytes, neurons, and pericytes form the neurovascular unit (NVU). Interactions with NVU cells endow BMECs with extremely tight barriers via the expression of tight junction proteins, a host of active efflux and nutrient transporters, and reduced transcellular transport. To recreate the BMEC-enhancing functions of NVU cells, we combined BMECs, astrocytes, neurons, and brain pericyte-like cells. Methods BMECs, neurons, astrocytes, and brain like pericytes were differentiated from human induced pluripotent stem cells (iPSCs) and placed in a Transwell-type NVU model. BMECs were placed in co-culture with neurons, astrocytes, and/or pericytes alone or in varying combinations and critical barrier properties were monitored. Results Co-culture with pericytes followed by a mixture of neurons and astrocytes (1:3) induced the greatest barrier tightening in BMECs, supported by a significant increase in junctional localization of occludin. BMECs also expressed active P-glycoprotein (PGP) efflux transporters under baseline BMEC monoculture conditions and continued to express baseline active PGP efflux transporters regardless of co-culture conditions. Finally, brain-like pericyte co-culture significantly reduced the rate of non-specific transcytosis across BMECs. Conclusions Importantly, each cell type in the NVU model was differentiated from the same donor iPSC source, yielding an isogenic model that could prove enabling for enhanced personalized modeling of the NVU in human health and disease.