Kurstakin Triggers Multicellular Behaviors in Bacillus cereus AR156 and Enhances Disease Control Efficacy Against Rice Sheath Blight.

Kurstakin is the latest discovered family of lipopeptides secreted by Bacillus spp. In this study, the effects of kurstakin on the direct antagonism, multicellularity, and disease control ability of Bacillus cereus AR156 were explored. An insertion mutation in the nonribosomal peptide synthase responsible for kurstakin synthesis led to a significant reduction of antagonistic ability of AR156 against the plant-pathogenic fungi Rhizoctonia solani, Ascochyta citrullina, Fusarium graminearum, and F. oxysporum f. sp. cubense. The loss of kurstakin synthesis ability significantly impaired the swarming motility of AR156 and reduced biofilm formation and amyloid protein accumulation. Although the loss of kurstakin synthesis ability did not reduce the competitiveness of AR156 under laboratory conditions, the colonization and environmental adaptability of the mutant was significantly weaker than that of wild-type AR156 on rice leaves. The cell surface of wild-type AR156 colonizing the leaf surface was covered by a thick biofilm matrix under a scanning electron microscope, but not the mutant. The colonization ability on rice roots and control efficacy against rice sheath blight disease of the mutant were also impaired. Thus, kurstakin participates in the control of plant diseases by B. cereus AR156 through directly inhibiting the growth of pathogenic fungi and improving long-term environmental adaptability and colonization of AR156 on the host surface by triggering multicellularity. This study explored the multiple functions of kurstakin in plant disease control by B. cereus.

The primary lesion apparent diffusion coefficient is a prognostic factor for locoregionally advanced nasopharyngeal carcinoma: a retrospective study.

BACKGROUND: To explore prognostic value of the pre-treatment primary lesion apparent diffusion coefficient (ADC) in locoregionally advanced nasopharyngeal carcinoma (LA-NPC). METHODS: A total of 843 patients with newly diagnosed LA-NPC were enrolled from January 2011 to April 2014 and divided into two groups based on ADC values: the low-ADC group and high-ADC group. The 3-year local relapse-free survival (LRFS), distant metastasis free survival (DMFS), disease-free survival (DFS) and overall survival (OS) rates between two groups were compared using Kaplan-Meier curve, and Cox regression analyses were performed to test prognostic value of the pretreatment ADC in LA-NPC. RESULTS: The cut-off value of the pretreatment ADC for predicting local relapse was 784.5 × 10- 6 mm2/s (AUC [area under curve] = 0.604; sensitivity = 0.640; specificity = 0.574), thus patients were divided into low-ADC (< 784.5 × 10- 6; n = 473) group and high-ADC (≥784.5 × 10- 6; n = 370) group. The low-ADC group had significantly higher 3-year LRFS rate and DFS rate than the high-ADC group (LRFS: 96.2% vs. 91.4%, P = 0.003; DFS: 81.4% vs. 73.0%, P = 0.0056). Multivariate analysis showed that the pretreatment ADC is an independent prognostic factor for LRFS (HR, 2.04; 95% CI, 1.13-3.66; P = 0.017) and DFS (HR, 1.41; 95% CI, 1.04-1.89; P = 0.024). CONCLUSIONS: The pretreatment ADC of the primary lesion is an independent prognostic factor for LRFS and DFS in LA-NPC patients.

Combination of beneficial bacteria improves blueberry production and soil quality.

Blueberry is an important agricultural crop with high nutritional, health, and economic value. Despite the well-studied blueberry cultivation methods and soil requirements, little is known about how beneficial bacteria function in organic blueberry cultivation systems and their effects on acidic soils. In this study, a single bacteria Bacillus amyloliquefaciens JC65 and three biocontrol bacteria consortiums containing JC65 were applied to organic system. The effect of bacteria to blueberry growth, yield, fruit quality, and soil quality was investigated. A consortium of three mixed Bacillus (B. amyloliquefaciens JC65, B. licheniforims HS10 and B. subtilis 7ze3) showed the highest growth improvement efficiency. The bacterial inoculation increased blueberry leaf chlorophyll content, net photosynthetic rate by 21.50%, 13.21% at 30 days, and increased average plant height by 2.72% at 69 days. Compared with the control, the inoculated plants showed an increased yield of 14.56%. Interestingly, blueberry fruit quality was also improved with supplement of the bacterial consortium. Fruit anthocyanin, soluble sugar, vitamin C, soluble solids, and soluble protein content were increased by 5.99%, 4.21%, 17.31%, 2.41%, and 21.65%, respectively. Besides, beneficial bacterial consortium also enables sustainable agriculture by improving soil ammonium nitrogen and organic matter by 3.77% and 2.96% after blueberry planting. In conclusion, the combination of beneficial bacteria showed a synergistic activity in organic system to promote the blueberry yield, fruit quality, and soil nutrient preservation.