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Switchgrass (Panicum virgatum L.) is a promising perennial bioenergy crop that achieves high yields with relatively low nutrient and energy inputs. Modification of cell wall composition for reduced recalcitrance can lower the costs of deconstructing biomass to fermentable sugars and other intermediates. We have engineered overexpression of OsAT10, encoding a rice BAHD acyltransferase and QsuB, encoding dehydroshikimate dehydratase from Corynebacterium glutamicum, to enhance saccharification efficiency in switchgrass. These engineering strategies demonstrated low lignin content, low ferulic acid esters, and increased saccharification yield during greenhouse studies in switchgrass and other plant species. In this work, transgenic switchgrass plants overexpressing either OsAT10 or QsuB were tested in the field in Davis, California, USA for three growing seasons. No significant differences in the content of lignin and cell wall-bound p-coumaric acid or ferulic acid were detected in transgenic OsAT10 lines compared with the untransformed Alamo control variety. However, the transgenic overexpressing QsuB lines had increased biomass yield and slightly increased biomass saccharification properties compared to the control plants. This work demonstrates good performance of engineered plants in the field, and also shows that the cell wall changes in the greenhouse were not replicated in the field, emphasizing the need to validate engineered plants under relevant field conditions.

With the development of the society, the emission laws are increasingly strict, and EGR and multiple pre-injection strategy can effectively reduce emissions. In order to study the influence of EGR rate and pre-injection on the emission and performance of engine, a computational fluid dynamics (CFD) simulation model was established based on GT power. By changing the EGR rate, the number of pre-injection and the amount of pre-injection, the best technology coupling point is explored. The results show that EGR can effectively reduce the generation of NOx, but it will lead to the increase of soot production and the decrease of power; pre-injection can improve the trade-off relationship between NOx and power.

In this paper, a specific engine is selected to perform a bench test to evaluate the performance of the diesel lubricating oil. The injection time of the original engine is changed , and an appropriate after-injection strategy is selected to achieve accelerated aging of the lubricating oil.In the engine bench test, oil samples are taken at regular intervals to analyze the physical and chemical indicators and tribological characteristics, to determine the regularity of the change of the oil aging degree. At the same time, two different kinds of diesel lubricating oil were used for the test, so as to compare the performance parameters of different kinds of the lubricating oil during the aging process.

Background: The availability of thousands of complete rice genome sequences from diverse varieties and accessions has laid the foundation for in-depth exploration of the rice genome. One drawback to these collections is that most of these rice varieties have long life cycles, and/or low transformation efficiencies, which limits their usefulness as model organisms for functional genomics studies. In contrast, the rice variety Kitaake has a rapid life cycle (9 weeks seed to seed) and is easy to transform and propagate. For these reasons, Kitaake has emerged as a model for studies of diverse monocotyledonous species. Results: Here, we report the de novo genome sequencing and analysis of Oryza sativa ssp. japonica variety KitaakeX, a Kitaake plant carrying the rice XA21 immune receptor. Our KitaakeX sequence assembly contains 377.6 Mb, consisting of 33 scaffolds (476 contigs) with a contig N50 of 1.4 Mb. Complementing the assembly are detailed gene annotations of 35,594 protein coding genes. We identified 331,335 genomic variations between KitaakeX and Nipponbare (ssp. japonica), and 2,785,991 variations between KitaakeX and Zhenshan97 (ssp. indica). We also compared Kitaake resequencing reads to the KitaakeX assembly and identified 219 small variations. The high-quality genome of the model rice plant KitaakeX will accelerate rice functional genomics. Conclusions: The high quality, de novo assembly of the KitaakeX genome will serve as a useful reference genome for rice and will accelerate functional genomics studies of rice and other species., BMC Genomics, 20, ISSN:1471-2164