Young Blair C, Thiers Barbara, White James F, Struwe Lena
Department of Ecology, Evolution, and Natural Resources, Rutgers University, 14 College Farm Road, New Brunswick, 08901, NJ, USA.
Department of Plant Biology, Rutgers University, 59 Dudley Road, New Brunswick, 08901, NJ, USA.
Am J Bot. 2025 Mar;112(3):e70017. doi: 10.1002/ajb2.70017. Epub 2025 Mar 11.
Interactions between endophytic microbes and bryophytes have been understudied. The liverwort oil body has also remained poorly understood since its discovery, and modern studies have failed to ascertain its function and composition. Many liverwort species possess oil bodies with conspicuous granules of unknown structure. We surveyed these granular liverwort oil bodies for the presence of bacteria to improve upon the understanding of liverworts, their oil bodies, and bacterial endophytes in nonvascular land plants.
Wild-collected specimens from living samples of Marchantia polymorpha and Radula complanata were stained with SYTO-13 and RADA to determine the presence or absence of bacteria within their oil bodies. Samples stained with calcofluor white, SYTO-13, and RADA were observed with confocal fluorescent microscopy for presence of nucleic acids and bacterial peptidoglycan cell walls within oil bodies.
We discovered large masses of bacteria within the oil bodies of M. polymorpha and R. complanata based on the presence of stained nucleic acids and peptidoglycans localized to the oil body "granules". Such bacteria were present in all oil bodies of the two species.
These newly discovered intraorganellar bacteria correspond to the previously described "granules" of oil bodies. The existence of granular oil bodies in many liverwort species implies that this endophytic association may not be isolated to species investigated here. Assessments of additional liverwort species for presence and identity of oil body bacteria are needed to understand this intriguing association in one of the oldest land plant lineages.
内生微生物与苔藓植物之间的相互作用尚未得到充分研究。自地钱油体被发现以来，人们对其了解也一直很少，现代研究未能确定其功能和组成。许多地钱物种拥有带有明显未知结构颗粒的油体。我们调查了这些颗粒状地钱油体中细菌的存在情况，以增进对苔藓植物、其油体以及非维管陆地植物中的细菌内生菌的了解。
对从野生采集的多歧地钱和扁枝石松活体样本中提取的标本用SYTO - 13和RADA进行染色，以确定其油体内是否存在细菌。用荧光增白剂、SYTO - 13和RADA染色的样本通过共聚焦荧光显微镜观察油体内核酸和细菌肽聚糖细胞壁的存在情况。
基于定位于油体“颗粒”的染色核酸和肽聚糖的存在，我们在多歧地钱和扁枝石松的油体内发现了大量细菌。这两个物种的所有油体中均存在此类细菌。
这些新发现的细胞器内细菌与先前描述的油体“颗粒”相对应。许多地钱物种中颗粒状油体的存在意味着这种内生关联可能并非仅限于此处研究的物种。需要对更多地钱物种进行评估，以确定油体细菌的存在情况和身份，从而了解这个最古老陆地植物谱系之一中的这种有趣关联。
