Department of Biology, Syracuse University, 107 College Place, Syracuse, NY, USA.
Tree Physiol. 2023 Sep 6;43(9):1571-1583. doi: 10.1093/treephys/tpad064.
Large-scale biofuel production from lignocellulosic feedstock is limited by the financial and environmental costs associated with growing and processing lignocellulosic material and the resilience of these plants to environmental stress. Symbiotic associations with arbuscular (AM) and ectomycorrhizal (EM) fungi represent a potential strategy for expanding feedstock production while reducing nutrient inputs. Comparing AM and EM effects on wood production and chemical composition is a necessary step in developing biofuel feedstocks. Here, we assessed the productivity, biomass allocation and secondary cell wall (SCW) composition of greenhouse-grown Populus tremuloidesMichx. inoculated with either AM or EM fungi. Given the long-term goal of reducing nutrient inputs for biofuel production, we further tested the effects of nutrient availability and nitrogen:phosphorus stoichiometry on mycorrhizal responses. Associations with both AM and EM fungi increased plant biomass by 14-74% depending on the nutrient conditions but had minimal effects on SCW composition. Mycorrhizal plants, especially those inoculated with EM fungi, also allocated a greater portion of their biomass to roots, which could be beneficial in the field where plants are likely to experience both water and nutrient stress. Leaf nutrient content was weakly but positively correlated with wood production in mycorrhizal plants. Surprisingly, phosphorus played a larger role in EM plants compared with AM plants. Relative nitrogen and phosphorus availability were correlated with shifts in SCW composition. For AM associations, the benefit of increased wood biomass may be partially offset by increased lignin content, a trait that affects downstream processing of lignocellulosic tissue for biofuels. By comparing AM and EM effects on the productivity and chemical composition of lignocellulosic tissue, this work links broad functional diversity in mycorrhizal associations to key biofuel traits and highlights the importance of considering both biotic and abiotic factors when developing strategies for sustainable biofuel production.
从木质纤维素原料大规模生产生物燃料受到与种植和加工木质纤维素材料相关的经济和环境成本的限制，以及这些植物对环境胁迫的恢复能力。与丛枝菌根（AM）和外生菌根（EM）真菌共生关系代表了一种扩大饲料生产同时减少养分投入的潜在策略。比较 AM 和 EM 对木材生产和化学成分的影响是开发生物燃料原料的必要步骤。在这里，我们评估了温室中生长的颤杨（Populus tremuloidesMichx.）接种 AM 或 EM 真菌后的生产力、生物量分配和次生细胞壁（SCW）组成。鉴于减少生物燃料生产中养分投入的长期目标，我们进一步测试了养分供应和氮磷化学计量比对菌根响应的影响。与 AM 和 EM 真菌的共生关系使植物生物量增加了 14-74%，具体取决于养分条件，但对 SCW 组成的影响很小。菌根植物，特别是那些接种了 EM 真菌的植物，也将更大比例的生物量分配给根部，这在植物可能同时经历水和养分胁迫的田间可能是有益的。叶养分含量与菌根植物的木材产量呈弱正相关。令人惊讶的是，磷在 EM 植物中的作用比 AM 植物更大。相对氮和磷的供应与 SCW 组成的变化有关。对于 AM 共生关系，增加木材生物量的好处可能会部分被增加的木质素含量所抵消，这一特性会影响木质纤维素组织的下游生物燃料加工。通过比较 AM 和 EM 对木质纤维素组织的生产力和化学成分的影响，这项工作将菌根共生关系的广泛功能多样性与关键生物燃料特性联系起来，并强调在制定可持续生物燃料生产策略时考虑生物和非生物因素的重要性。
