Agave REVEILLE1 regulates the onset and release of seasonal dormancy in Populus.

Deciduous woody plants like poplar (Populus spp.) have seasonal bud dormancy. It has been challenging to simultaneously delay the onset of bud dormancy in the fall and advance bud break in the spring, as bud dormancy, and bud break were thought to be controlled by different genetic factors. Here, we demonstrate that heterologous expression of the REVEILLE1 gene (named AaRVE1) from Agave (Agave americana) not only delays the onset of bud dormancy but also accelerates bud break in poplar in field trials. AaRVE1 heterologous expression increases poplar biomass yield by 166% in the greenhouse. Furthermore, we reveal that heterologous expression of AaRVE1 increases cytokinin contents, represses multiple dormancy-related genes, and up-regulates bud break-related genes, and that AaRVE1 functions as a transcriptional repressor and regulates the activity of the DORMANCY-ASSOCIATED PROTEIN 1 (DRM1) promoter. Our findings demonstrate that AaRVE1 appears to function as a regulator of bud dormancy and bud break, which has important implications for extending the growing season of deciduous trees in frost-free temperate and subtropical regions to increase crop yield.

Nitrogen addition alters soil fungal communities, but root fungal communities are resistant to change.

Plants are colonized by numerous microorganisms serving important symbiotic functions that are vital to plant growth and success. Understanding and harnessing these interactions will be useful in both managed and natural ecosystems faced with global change, but it is still unclear how variation in environmental conditions and soils influence the trajectory of these interactions. In this study, we examine how nitrogen addition alters plant-fungal interactions within two species of Populus - Populus deltoides and P. trichocarpa. In this experiment, we manipulated plant host, starting soil (native vs. away for each tree species), and nitrogen addition in a fully factorial replicated design. After ~10 weeks of growth, we destructively harvested the plants and characterized plant growth factors and the soil and root endosphere fungal communities using targeted amplicon sequencing of the ITS2 gene region. Overall, we found nitrogen addition altered plant growth factors, e.g., plant height, chlorophyll density, and plant N content. Interestingly, nitrogen addition resulted in a lower fungal alpha diversity in soils but not plant roots. Further, there was an interactive effect of tree species, soil origin, and nitrogen addition on soil fungal community composition. Starting soils collected from Oregon and West Virginia were dominated by the ectomycorrhizal fungi Inocybe (55.8% relative abundance), but interestingly when P. deltoides was grown in its native West Virginia soil, the roots selected for a high abundance of the arbuscular mycorrhizal fungi, Rhizophagus. These results highlight the importance of soil origin and plant species on establishing plant-fungal interactions.

Autologous Hematopoetic Stem Cell Transplantation for Refractory Crohn Disease: A Randomized Clinical Trial.

IMPORTANCE: Case reports and series suggest hematopoietic stem cell transplantation (HSCT) may benefit some patients with Crohn disease. OBJECTIVE: To evaluate the effect of autologous HSCT on refractory Crohn disease. DESIGN, SETTING, AND PARTICIPANTS: Parallel-group randomized clinical trial conducted in 11 European transplant units from July 2007 to September 2011, with follow-up through March 2013. Patients were aged 18 to 50 years with impaired quality of life from refractory Crohn disease not amenable to surgery despite treatment with 3 or more immunosuppressive or biologic agents and corticosteroids. INTERVENTIONS: All patients underwent stem cell mobilization before 1:1 randomization to immunoablation and HSCT (n = 23) or control treatment (HSCT deferred for 1 year [n = 22]). All were given standard Crohn disease treatment as needed. MAIN OUTCOMES AND MEASURES: Sustained disease remission at 1 year, a composite primary end point comprising clinical remission (Crohn Disease Activity Index (CDAI) <150 [range, 0-600]), no use of corticosteroids or immunosuppressive or biologic drugs for at least the last 3 months, and no endoscopic or radiological evidence of active (erosive) disease anywhere in the gastrointestinal (GI) tract. Secondary outcomes were individual components of the primary composite outcome and other measures of disease activity, laboratory results, quality of life and functional status, and GI tract imaging. RESULTS: Twenty-three patients underwent HSCT and 22 received standard Crohn disease treatment (controls). Sustained disease remission was achieved in 2 patients undergoing HSCT (8.7%) vs 1 control patient (4.5%) (absolute difference, 4.2% [95% CI, -14.2% to 22.6%]; P = .60). Fourteen patients undergoing HSCT (61%) vs 5 control patients (23%) had discontinued immunosuppressive or biologic agents or corticosteroids for at least 3 months (difference, 38.1% [95% CI, 9.3% to 59.3%]; P = .01). Ten vs 2 patients had a CDAI less than 150 (remission) at the final evaluation, 8 (34.8%) vs 2 (9.1%) for 3 or more months (difference, 25.7% [95% CI, 1.1% to 47.1%]; P = .052). Eight (34.8%) vs 2 (9.1%) patients were adjudicated free of active disease on endoscopy and radiology at final assessment (difference, 25.7% [95% CI, 1.1% to 47.1%]; P = .054). There were 76 serious adverse events in patients undergoing HSCT vs 38 in controls. One patient undergoing HSCT died. CONCLUSIONS AND RELEVANCE: Among adult patients with refractory Crohn disease not amenable to surgery who had impaired quality of life, HSCT, compared with conventional therapy, did not result in a statistically significant improvement in sustained disease remission at 1 year and was associated with significant toxicity. These findings do not support the widespread use of HSCT for patients with refractory Crohn disease. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00297193.

Role of essential oils in control of Rhizoctonia damping-off in tomato with bioactive Monarda herbage.

Plants in the genus Monarda produce complex essential oils that contain antifungal compounds. The objectives of this research were to identify selections of monarda that reduce Rhizoctonia damping-off of tomato, and to determine relationships between essential oil composition of 13 monarda herbages (dried and ground leaves) and disease suppression. Herbages were grouped into five chemotypes, based on essential oil composition and effective concentrations for reducing growth by 50% for Rhizoctonia solani. Replicated and repeated disease control assays were conducted with monarda herbages in greenhouse medium, with or without Rhizoctonia. Percent survival, seedling height, and stem diameter were evaluated at 8 weeks. Survival, seedling height, and stem diameter in herbage-only treatments were not different from the control (no-herbage, no-pathogen) for most herbage treatments. In the pathogen control (no-herbage + Rhizoctonia), seedling survival was 10% that of the control. In pathogen-infested media, seedling survival ranged from 65 to 80% for treatments with thymol chemotypes and 55 to 65% for carvacrol chemotypes. Effective control of Rhizoctonia damping-off was correlated with phenolic monoterpenes; herbages classified as carvacrol chemotypes effectively protected tomato seedlings from Rhizoctonia damping-off disease without phytotoxicity. This study provides evidence that monarda herbages have potential as growing media amendments for control of Rhizoctonia damping-off disease.