Vandergrift Gregory W, Bell Sheryl L, Schrader Shannon E, Jensen Sonja M, Wahl Jon H, Tagestad Jerry D, China Swarup, Hofmockel Kirsten S
Pacific Northwest National Laboratory (PNNL), Richland, Washington 99352, United States.
ACS Earth Space Chem. 2024 Aug 30;8(10):1961-1969. doi: 10.1021/acsearthspacechem.4c00046. eCollection 2024 Oct 17.
While crop and grassland usage continues to increase, the full diversity of plant-specific volatile organic compounds (VOCs) emitted from these ecosystems, including their implications for atmospheric chemistry and carbon cycling, remains poorly understood. It is particularly important to investigate VOCs in the context of potential biofuels: aside from the implications of large-scale land use, harvest may shift both the flux and speciation of emitted VOCs. To this point, we evaluate the diversity of VOCs emitted both pre and postharvest from "Alkar" tall wheatgrass (), a candidate biofuel that exhibits greater tolerance to frost and saline land compared to other grass varieties. Mature plants grown under field conditions ( = 6) were sampled for VOCs both pre- and postharvest (October 2022). Via hierarchical clustering of emitted VOCs from each plant, we observe distinct "volatilomes" (diversity of VOCs) specific to the pre- and postharvest conditions despite plant-to-plant variability. In total, 50 VOCs were found to be unique to the postharvest tall wheatgrass volatilome, and these unique VOCs constituted a significant portion (26%) of total postharvest signal. While green leaf volatiles (GLVs) dominate the speciation of postharvest emissions (e.g., 54% of unique postharvest VOC signal was due to 1-penten-3-ol), we demonstrate novel postharvest VOCs from tall wheatgrass that are under characterized in the context of carbon cycling and atmospheric chemistry (e.g., 3-octanone). Continuing evaluations will quantitatively investigate tall wheatgrass VOC fluxes, better informing the feasibility and environmental impact of tall wheatgrass as a biofuel.
虽然农作物和草地的使用面积持续增加，但人们对这些生态系统排放的植物特定挥发性有机化合物（VOCs）的全部多样性，包括其对大气化学和碳循环的影响，仍知之甚少。在潜在生物燃料的背景下研究挥发性有机化合物尤为重要：除了大规模土地利用的影响外，收获可能会改变挥发性有机化合物的通量和种类。就此而言，我们评估了 “Alkar” 高羊茅（一种候选生物燃料，与其他草种相比，对霜冻和盐碱地具有更强的耐受性）收获前后排放的挥发性有机化合物的多样性。对在田间条件下生长的成熟植株（n = 6）在收获前和收获后（2022年10月）进行挥发性有机化合物采样。通过对每株植物排放的挥发性有机化合物进行层次聚类，我们观察到尽管植株之间存在差异，但收获前和收获后的条件具有特定的不同 “挥发组”（挥发性有机化合物的多样性）。总共发现50种挥发性有机化合物是收获后高羊茅挥发组所特有的，这些独特的挥发性有机化合物占收获后总信号的很大一部分（26%）。虽然绿叶挥发物（GLVs）在收获后排放的种类中占主导地位（例如，收获后独特挥发性有机化合物信号的54% 是由1-戊烯-3-醇引起的），但我们展示了高羊茅收获后新的挥发性有机化合物，这些化合物在碳循环和大气化学方面的特征尚不明确（例如，3-辛酮）。持续的评估将定量研究高羊茅挥发性有机化合物的通量，从而更好地了解高羊茅作为生物燃料的可行性和环境影响。
