Conservation and diversification of the miR166 family in soybean and potential roles of newly identified miR166s

Identity between pre-miR166s in soybean. (TIF 5906 kb

Histone H3 Lysine 9 Methyltransferase DIM5 Is Required for the Development and Virulence of Botrytis cinerea

Histone methylation is widely present in animals, plants and fungi, and the methylation modification of histone H3 has important biological functions. Methylation of Lys9 of histone H3 (H3K9) has been proven to regulate chromatin structure, gene silencing, transcriptional activation, plant metabolism and other processes. In this work, we investigated the functions of a H3K9 methyltransferase gene BcDIM5 in Botrytis cinerea, which contains a PreSET domain, a SET domain and a PostSET domain. Characterization of BcDIM5 knockout transformants showed that the hyphal growth rate and production of conidiophores and sclerotia were significantly reduced, while complementary transformation of BcDIM5 could restore the phenotypes to the levels of wild type. Pathogenicity assays revealed that BcDIM5 was essential for full virulence of B. cinerea. BcDIM5 knockout transformants exhibited decreased virulence, down-regulated expression of some pathogenic genes and drastically decreased H3K9 trimethylation level. However, knockout transformants of other two genes heterochromatin protein 1 (HP1) BcHP1 and DNA methyltransferase (DIM2) BcDIM2 did not exhibit significant change in the growth phenotype and virulence compared with the wild type. Our results indicate that H3K9 methyltransferase BcDIM5 is required for H3K9 trimethylation to regulate the development and virulence of B. cinerea

The Solution of Nonlinear Fourth-Order Differential Equation with Integral Boundary Conditions

An iterative algorithm is proposed for solving the solution of a nonlinear fourth-order differential equation with integral boundary conditions. Its approximate solution un(x) is represented in the reproducing kernel space. It is proved that un(x) converges uniformly to the exact solution u(x). Moreover, the derivatives of un(x) are also convergent to the derivatives of u(x). Numerical results show that the method employed in the paper is valid

Trends of ambient fine particles and major chemical components in the Pearl River Delta region: Observation at a regional background site in fall and winter

In the fall and winter of 2007 to 2011, 167 24-h quartz filter-based fine particle (PM2.5) samples were collected at a regional background site in the central Pearl River Delta. The PM2.5 showed an annual reduction trend with a rate of 8.58 mu g m(-3) (p < 0.01). The OC component of the PM2.5 reduced by 1.10 mu g m(-3) yr(-1) (p < 0.01), while the reduction rates of sulfur dioxide (SO2) and sulfate (SO42-) were 10.2 mu g m(-3) yr(-1) (p < 0.01) and 1.72 mu g m(-3) yr(-1) (p < 0.01), respectively. In contrast, nitrogen oxides (NOx) and nitrate (NO3-) presented growth trends with rates of 6.73 mu g m(-3) yr(-1) (p < 0.05) and 0.79 mu g m(-3) yr(-1) (p < 0.05), respectively. The PM2.5 reduction was mainly related to the decrease of primary OC and SO42-, and the enhanced conversion efficiency of SO2 to SO42- was related to an increase in the atmospheric oxidizing capacity and a decrease in aerosol acidity. The discrepancy between the annual trends of NOx and NO3- was attributable to the small proportion of NO3- in the total nitrogen budget. Capsule abstract: Understanding annual variations of PM2.5 and its chemical composition is crucial in enabling policymakers to formulate and implement control strategies on particulate pollution.Department of Civil and Environmental Engineerin

Engineering lanthipeptides by introducing a large variety of RiPP modifications to obtain new-to-nature bioactive peptides

Natural bioactive peptide discovery is a challenging and time-consuming process. However, advances in synthetic biology are providing promising new avenues in peptide engineering that allow for the design and production of a large variety of new-to-nature peptides with enhanced or new bioactivities, using known peptides as templates. Lanthipeptides are ribosomally synthesized and posttranslationally modified peptides (RiPPs). The modularity of post-translational modification (PTM) enzymes and ribosomal biosynthesis inherent to lanthipeptides enables their engineering and screening in a high-throughput manner. The field of RiPPs research is rapidly evolving, with many novel PTMs and their associated modification enzymes being identified and characterized. The modularity presented by these diverse and promiscuous modification enzymes has made them promising tools for further in vivo engineering of lanthipeptides, allowing for the diversification of their structures and activities. In this review, we explore the diverse modifications occurring in RiPPs and discuss the potential applications and feasibility of combining various modification enzymes for lanthipeptide engineering. We highlight the prospect of lanthipeptide- and RiPP-engineering to produce and screen novel peptides, including mimics of potent non-ribosomally produced antimicrobial peptides (NRPs) such as daptomycin, vancomycin, and teixobactin, which offer high therapeutic potential.</p

The Effect of Soluble Ammonium Polyphosphate on the Properties of Water Blown Semirigid Polyurethane Foams

Soluble ammonium polyphosphate (SAPP) is employed to prepare flame retardant semirigid polyurethane foam (SPUF) using water as blowing agent. The flame retardant property of SPUF is evaluated by limiting oxygen index (LOI) and horizontal burning test. Also the thermal degradation mechanism is studied by TG and Fourier transform infrared (FTIR). The results show that, with the increase of the content of SAPP, flame retardant property of SPUF improves obviously as the LOI value increases and the horizontal burning rate decreases. And residual char is increased up to 20% with 19 wt% SAPP. Moreover, the mechanical property of SPUF is enhanced dramatically