Molecular design of polysaccharides for improving the sustainable straw utilization value in rice

提高水稻秸秆可持续利用价值的多糖分子设计

• 批准号: 410274474
• 负责人: Professor Dr. Markus Pauly
• 金额: --
• 依托单位: National Natural Science Foundation of China
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/410274474?language=en
• 关键词: Molecular; design; polysaccharides; improving; sustainable

Crop straw can be considered an abundant agricultural waste. But, crop straw contains large amount of cell-wall polymers, also referred to as lignocellulosics, which can be used as feed and as a renewable resource for the sustainable production of commodity chemicals such as biofuels. Conversion of crop straw into higher value products is therefore of great importance for agriculture sustainability. Processing lignocellulosic crop materials to chemicals involves pretreatment of the material and enzymatic release of the sugars, which are then fermented to products by microbes. However, not all sugars present in lignocellulosics can be fermented with the same efficiency. Hexoses are preferred by fermenting microbes over pentoses. Hence, increasing the sugar content in particular the hexose/pentose ratio of lignocellulosic material will increase the product yield. Based on the previous studies of both groups we want to increase the sugar and hexose/pentose ratio in lignocellulosic material of rice by increasing the polysaccharides mixed-linkage glucan (MLG) and glucomannan in rice, while concomitantly reducing xylans (pentose rich polymers). To achieve these goals we plan to (i) identify and characterize plant candidate genes that contribute to high MLG content in grasses; (ii) uncovering how mannansynthases control (gluco)mannan synthesis; (iii) transferring the knowledge obtained in (i) and (ii) to rice varieties by the genome editing CRISPR/CAS9 approach to increase the abundance of both polymers in rice without negative impacts on plant growth and thus biomass production. A successful outcome in rice can be transferred to more temperate grasses such as barley. The outcome may therefore be of significant importance for China and Germany's sustainable agriculture production and crop straw utilization.

农作物秸秆可以被认为是大量的农业废弃物。但是，农作物秸秆含有大量的细胞壁聚合物，也称为木质纤维素，其可用作饲料和可再生资源，用于可持续生产商品化学品，如生物燃料。因此，将农作物秸秆转化为更高价值的产品对农业可持续发展至关重要。将木质纤维素作物材料加工成化学品涉及材料的预处理和糖的酶促释放，然后通过微生物发酵成产品。然而，并非所有存在于木质纤维素中的糖都可以以相同的效率发酵。发酵微生物优选己糖而不是戊糖。因此，增加木质纤维素材料的糖含量，特别是己糖/戊糖比率将增加产物产率。基于这两个群体的先前研究，我们希望通过增加大米中的多糖混合键合葡聚糖（MLG）和葡甘露聚糖来增加大米的木质纤维素材料中的糖和己糖/戊糖比率，同时减少木聚糖（富含戊糖的聚合物）。为了实现这些目标，我们计划（i）鉴定和表征有助于草中高MLG含量的植物候选基因;（ii）揭示甘露聚糖酶如何控制（葡萄糖）甘露聚糖合成;（iii）通过基因组编辑CRISPR/CRISPR技术将（i）和（ii）中获得的知识转移到水稻品种上。CAS9方法增加水稻中两种聚合物的丰度，而不会对植物生长和生物质生产产生负面影响。水稻的成功结果可以转移到更温和的禾本科植物，如大麦。 研究结果对中国和德国的农业可持续生产和秸秆利用具有重要意义。