Differences in Fatty Acids and Related Carbohydrate Components in <i>Arthrobotrys flagrans</i> Chlamydospores at Different Stages

Chlamydospore of Arthrobotrys flagrans, a nematophagous fungus, is an effective component of biological control preparations for parasitic nematodes in animals and plants. To explore the differences in the chemical components of the spores at different physiological stages, the total fatty acid was extracted by organic solvent method after the test chlamydospore cytoderm was broken, and then the fatty acid type and content were determined by gas chromatogram-mass spectrometry (GC-MS). The contents of trehalose, glucose and glycerol in spores were determined by liquid chromatography (HPLC). The results showed that two kinds of fatty acids were detected in non-dormant spores, of which 65.99% were unsaturated fatty acids. Three kinds of fatty acids were detected in dormant spores, of which 71.98% were unsaturated fatty acids. Nine kinds of fatty acids were detected from germination spores, and unsaturated fatty acids accounted for 88.73%. Trehalose content in non-dormant spores (germination rate 54.8%) was significantly higher than that in dormant spores (germination rate 0.94 ~ 4.92%) (p < 0.05). The content of glycerol in dormant spores was significantly higher than that in non-dormant spores (p < 0.05), and the content of glucose was not significantly different between the two groups. In conclusion, the contents of glycerol, trehalose and fatty acid were different in chlamydospore at different physiological stages. These compositional differences suggest that trehalose and glycerol may function as osmoprotectants to maintain cellular integrity during dormancy, and elevated unsaturated fatty acids likely enhance membrane fluidity under low-temperature stress, thereby promoting overwintering survival.