Coastal marsh habitats are impacted by many factors or disturbances, including habitat destruction, pollution, and the introduction of invasive species. Spartina alterniflora (S. alterniflora) is an important invasive species, accounting for a significant proportion of the invasive plants spread around the world. Salt stress is a major environmental stress factor, which affects plant growth and development. Little information is available regarding S. alterniflora microRNAs (miRNAs) which play important regulatory roles in plant growth and development. In order to detect S. alterniflora miRNAs and determine any expression differences between S. alterniflora plants cultivated on ordinary soils from the greenhouse and salty soils from Dafeng, in Jiangsu province of China, we carried out the detection and quantification of S. alterniflora miRNAs by microarray. Among the 81 miRNAs identified as significantly down- or up-regulated under the salt stress, 21 of the miRNAs represent 8 miRNA gene families in S. alterniflora. We found that miR168, miR399, miR395, miR393, miR171, miR396, miR169, and miR164 were down-regulated under salinity stress, and 60 of the miRNAs were up-regulated, which were revealed to be induced by salt stress in plants. The identification of differentially expressed novel plant miRNAs and their target genes, and the analysis of expression, provide molecular evidence for the possible involvement of miRNAs in the process of salt response and/or salt tolerance in S. alterniflora.

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Lemongrass fiber was analyzed to determine the chemical proportion of its lignocellulosic components. Fibers' thermal behavior, surface structures, and functionality were assessed by thermogravimetric analysis (TGA), scanning electron microscope (SEM), and Fourier transforminfrared spectroscopy (FT-IR), respectively. High-density polyethylene (HDPE) matrix composites filled with varying (10%, 20%, 30%, 40%, and 50%) fiber content were prepared and investigated. Composite wicker was made from HDPE and low density polyethylene (LDPE) blend-matrix and 10% alkaline modified fiber. Alkaline or maleic anhydride grafted polypropylene (MA-g-PP) was used to improve the compatibility between the fiber and matrices. The composites were evaluated by using TGA, SEM microscopy, and universal testing machine, respectively. The fiber was constituted by equitable amounts of lignocellulosic components with cellulose accounting for the highest proportion. It also exhibited high degradation temperature, which was further increased following alkaline modification. Superior thermal degradation behavior was measured for modified fiber composites. SEM showed that the modified fiber composites demonstrated better compatibility. Lemongrass fiber reinforcement substantially improved the mechanical properties of the composites.

This study investigates the effect of modified wheat straw on the physical and mechanical properties of modified wheat straw/high-density polyethylene (MWS/HDPE) straw-plastic composites. Wheat straw fibers with particle sizes in the range of 0.25 to 0.50 mm were modified with caprolactam (CPL). A Fourier transform infrared spectroscopy (FT-IR) analysis of MWS showed that when the CPL level was 5%, the intensity of the hydroxyl (O-H) and carbonyl (C-O) absorption peaks noticeably decreased, indicating a corresponding decrease in the polarity of the fibers. A physical analysis of the wheat straw fibers indicated that after the modification, the characteristics of the fibers were closer to those of the HDPE polymer matrix, thus contributing to good compatibility and dispersion of the straw fibers within the matrix. The composites of the highdensity polyethylene with modified wheat straw particles were successfully synthesized using the melt blend method. The prepared composites were characterized using scanning electron microscopy (SEM), and their mechanical properties were investigated. The MWS/HDPE composites showed superior mechanical properties because of a greater compatibility of MWS with HDPE. The modified WS fibers function as "biological steel," reinforcing the HDPE to produce bio-composites.

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