The Transcriptional Responses of Ectomycorrhizal Fungus, Cenococcum geophilum, to Drought Stress

Abstract

With global warming, drought has become one of the major environmental pressures that threaten the development of global agricultural and forestry production. Cenococcum geophilum (C. geophilum) is one of the most common ectomycorrhizal fungi in nature, which can form mycorrhiza with a large variety of host trees of more than 200 tree species from 40 genera of both angiosperms and gymnosperms. In this study, six C. geophilum strains with different drought tolerance were selected to analyze their molecular responses to drought stress with treatment of 10% polyethylene glycol. Our results showed that drought-sensitive strains absorbed Na and K ions to regulate osmotic pressure and up-regulated peroxisome pathway genes to promote the activity of antioxidant enzymes to alleviate drought stress. However, drought-tolerant strains responded to drought stress by up-regulating the functional genes involved in the ubiquinone and other terpenoid-quinone biosynthesis and sphingolipid metabolism pathways. The results provided a foundation for studying the mechanism of C. geophilum response to drought stress.

The Ectomycorrhizal Fungi and Soil Bacterial Communities of the Five Typical Tree Species in the Junzifeng National Nature Reserve, Southeast China

“…The inoculation of C. geophilum in Masson pine seedlings resulted in enhanced plant growth and stress resistance through improved biomass production, photosynthesis, and nutrient status [41]. Our previous research confirmed that C. geophilum exhibited resistance to drought, high temperature, and heavy metal stress by increasing nutrient absorption and antioxidant enzyme activity and upregulating genes encoding antioxidant enzyme activity, ubiquinone, and other terpenoid quinones and metabolism of compounds [42][43][44]. Additionally, our research demonstrated that the inoculation of C. geophilum effectively alleviated heavy metal-induced toxicity in Pinus massoniana seedlings [45].…”

Physiological and Transcriptome Responses of Pinus massoniana Seedlings Inoculated by Various Ecotypes of the Ectomycorrhizal Fungus Cenococcum geophilum during the Early Stage of Drought Stress

“…Cenococcum geophilum, characterized by abundant genetic diversity, holds ecological significance linked to its genetic variations [21]. Numerous studies have highlighted the varying resistance levels of different ecotypic strains of C. geophilum to stresses such as drought, high temperature, heavy metals, and salt [23,[37][38][39]. Nevertheless, existing studies primarily focus on the strain's inherent stress resistance mechanism, with limited exploration of the symbiotic relationship between strains and plants in facing diverse stresses.…”

“…Research by Coleman et al [22] has illuminated its role in preserving cellular integrity under conditions of water deficit while mitigating the surge in reactive oxygen species (ROS) typically observed during drought stress. Furthermore, recent findings by Li et al [23] underscore the ability of different ecotypes of C. geophilum to induce the expression of drought-related genes when subjected to drought conditions, thereby enhancing drought resistance. It is important to note that different ecotypes of C. geophilum exhibit distinct responses to drought, presenting an intriguing avenue for further exploration in this context.…”

Analysis of the distribution pattern of the ectomycorrhizal fungus Cenococcum geophilum under climate change using the optimized MaxEnt model

“…The survival of C. geophilum in the Arctic further supports this observation (Miyamoto et al, 2022 ). Additionally, C. geophilum can thrive even under relatively arid conditions, potentially due to its ability to regulate osmotic pressure, and enhance antioxidant enzyme activity and alleviate drought stress (Li, Yuan, et al, 2022 ).…”