Multiprotein bridging factor 1 （MBF1） is a transcriptional co-activator related to stress tolerance in various organisms. We investigated the nucleotide differences in the mbfl gene in the lichen-forming fungus Umbi...Multiprotein bridging factor 1 （MBF1） is a transcriptional co-activator related to stress tolerance in various organisms. We investigated the nucleotide differences in the mbfl gene in the lichen-forming fungus Umbilicaria decussata collected from polar （i.e., Antarctica and the Arctic） and non-polar （i.e., Armenia） regions. The 552-bp Udmbfl genes isolated from eight samples contained numerous sequence variations, including single nucleotide polymorphisms as well as insertions and deletions. The frequency of nucleotide changes was higher in the intron than in the coding sequence. The nucleotide polymorphism levels （n=0.01792, 0=-0.01792） and haplotype diversity （Hd=-l） in the Udmbfl gene from Antarctic samples were relatively high. Additionally, of the 19 detected nucleotide sequence variation sites, 15 were observed only in Antarctic samples. The resulting amino acid changes occurred in the N-terminal, whose function remains unknown. Although these DNA polymorphisms and amino acid changes have been verified in Antarctic samples of U. decussata, there is still little evidence indicating that different environmental conditions affected the functional evolution of Udmbfl. Additional studies involving more U. decussata samples fi＇om representative ecotypes will be necessary to tmcover the relationships among DNA polymorphisms, functional gene evolution, and lichen habitats.展开更多
This work deals with the survival analyses of the symbionts isolated from the lichen E.pusillum under desiccation and starvation stress.The mycobiont of the symbionts was under the desiccation in combination with star...This work deals with the survival analyses of the symbionts isolated from the lichen E.pusillum under desiccation and starvation stress.The mycobiont of the symbionts was under the desiccation in combination with starvation stress,and under starvation stress alone as well.The phycobiont of the symbionts was under desiccation stress alone.The experiments were detected by means of the biomass size,weight and cell density,deformity of the hyphae and cells,and metabolic activity through SEM (scanning electron microscopy),TEM (transmission electron microscopy),FM (fluorescence microscopy),spectrophotometry,and FCM (flow cytometry).The results show that the mycobiont can survive for seven months under desiccation stress in combination with starvation stress,and for eight months under starvation stress alone.The phycobiont can survive for two months under desiccation stress.It can provide a scientific basis for further research of the reproduction biology of lichens and arid desert biocarpet engineering to fix sand and carbon.展开更多
This study investigated the photosynthetic rate of the lichen Endocarpon pusillum at the Chinese Academy of Sciences Shapotou Desert Research Station and estimated its annual contribution to the carbon budget in the e...This study investigated the photosynthetic rate of the lichen Endocarpon pusillum at the Chinese Academy of Sciences Shapotou Desert Research Station and estimated its annual contribution to the carbon budget in the ecosystem. The software SigmaPlot 10.0 with "Macro-Area below curves" was used to calculate the carbon fixation capacity of the lichen. The total carbon budget (ΣC) of the lichen was obtained by subtracting the respiratory carbon loss (ΣDR) from the photosynthetic carbon gain (ΣNP). Because water from precipitation plays an important role in photosynthesis in this ecosystem, the annual carbon budget of E. pusillum at the station was estimated based on the three-year average precipitation data from 2009 to 2011. Our results indicate that the lichen fixes 14.6 g Cm-2 annually. The results suggest that artificial inoculation of the crust lichen in the Tengger Desert could not only help reduce the sand and dust storms but also offer a significant carbon sink, fixing a total of 438000 t of carbon over the 30000 km2 of the Tengger Desert. The carbon sink could potentially help mitigate the atmospheric greenhouse effect. Our study suggests that the carpet-like lichen E. pusillum is an excellent candidate for "Bio-carpet Engineering" of arid and semi-arid regions.展开更多
The lichen-forming fungus was isolated from the desert lichen Endocarpon pusillum that is extremely drought resistant.To understand the molecular mechanisms of drought resistance in the fungus,we employed RNA-seq and ...The lichen-forming fungus was isolated from the desert lichen Endocarpon pusillum that is extremely drought resistant.To understand the molecular mechanisms of drought resistance in the fungus,we employed RNA-seq and quantitative real-time PCR to compare and characterize the differentially expressed genes in pure culture at two different water levels and with that in desiccated lichen.The comparative transcriptome analysis indicated that a total of 1781 genes were differentially expressed between samples cultured under normal and PEG-induced drought stress conditions.Similar to those in drought resistance plants and non-lichenized fungi,the common drought-resistant mechanisms were differentially expressed in E.pusillum.However,the expression change of genes involved in osmotic regulation in E.pusillum is different,which might be the evidence for the feature of drought adaptation.Interestingly,different from other organisms,some genes involved in drought adaption mechanisms showed significantly different expression patterns between the presence and absence of drought stress in E.pusillum.The expression of 23 candidate stress responsive genes was further confirmed by quantitative real-time PCR using dehydrated E.pusillum lichen thalli.This study provides a valuable resource for future research on lichen-forming fungi and shall facilitate future functional studies of the specific genes related to drought resistance.展开更多
基金supported by grants from the National Natural Science Foundation of China (Grant no.31500012)the Chinese Arctic and Antarctic Administration (Grant no.2016YR05005)
文摘Multiprotein bridging factor 1 （MBF1） is a transcriptional co-activator related to stress tolerance in various organisms. We investigated the nucleotide differences in the mbfl gene in the lichen-forming fungus Umbilicaria decussata collected from polar （i.e., Antarctica and the Arctic） and non-polar （i.e., Armenia） regions. The 552-bp Udmbfl genes isolated from eight samples contained numerous sequence variations, including single nucleotide polymorphisms as well as insertions and deletions. The frequency of nucleotide changes was higher in the intron than in the coding sequence. The nucleotide polymorphism levels （n=0.01792, 0=-0.01792） and haplotype diversity （Hd=-l） in the Udmbfl gene from Antarctic samples were relatively high. Additionally, of the 19 detected nucleotide sequence variation sites, 15 were observed only in Antarctic samples. The resulting amino acid changes occurred in the N-terminal, whose function remains unknown. Although these DNA polymorphisms and amino acid changes have been verified in Antarctic samples of U. decussata, there is still little evidence indicating that different environmental conditions affected the functional evolution of Udmbfl. Additional studies involving more U. decussata samples fi＇om representative ecotypes will be necessary to tmcover the relationships among DNA polymorphisms, functional gene evolution, and lichen habitats.
基金supported by the National Natural Science Foundation of China (Grant No.30670004)Ministry of Science and Technology of China (Grant No.2007AA021405)
文摘This work deals with the survival analyses of the symbionts isolated from the lichen E.pusillum under desiccation and starvation stress.The mycobiont of the symbionts was under the desiccation in combination with starvation stress,and under starvation stress alone as well.The phycobiont of the symbionts was under desiccation stress alone.The experiments were detected by means of the biomass size,weight and cell density,deformity of the hyphae and cells,and metabolic activity through SEM (scanning electron microscopy),TEM (transmission electron microscopy),FM (fluorescence microscopy),spectrophotometry,and FCM (flow cytometry).The results show that the mycobiont can survive for seven months under desiccation stress in combination with starvation stress,and for eight months under starvation stress alone.The phycobiont can survive for two months under desiccation stress.It can provide a scientific basis for further research of the reproduction biology of lichens and arid desert biocarpet engineering to fix sand and carbon.
基金supported by the National Natural Science Foundation of China (31070018)the Knowledge Innovation Program of the Chinese Academy of Sciences (2010-Biols-CAS-0104)Ministry of Science and Technology of China (2011BAC07B03)
文摘This study investigated the photosynthetic rate of the lichen Endocarpon pusillum at the Chinese Academy of Sciences Shapotou Desert Research Station and estimated its annual contribution to the carbon budget in the ecosystem. The software SigmaPlot 10.0 with "Macro-Area below curves" was used to calculate the carbon fixation capacity of the lichen. The total carbon budget (ΣC) of the lichen was obtained by subtracting the respiratory carbon loss (ΣDR) from the photosynthetic carbon gain (ΣNP). Because water from precipitation plays an important role in photosynthesis in this ecosystem, the annual carbon budget of E. pusillum at the station was estimated based on the three-year average precipitation data from 2009 to 2011. Our results indicate that the lichen fixes 14.6 g Cm-2 annually. The results suggest that artificial inoculation of the crust lichen in the Tengger Desert could not only help reduce the sand and dust storms but also offer a significant carbon sink, fixing a total of 438000 t of carbon over the 30000 km2 of the Tengger Desert. The carbon sink could potentially help mitigate the atmospheric greenhouse effect. Our study suggests that the carpet-like lichen E. pusillum is an excellent candidate for "Bio-carpet Engineering" of arid and semi-arid regions.
基金supported by the National Natural Science Foundation of China(31270018)the Knowledge Innovation Program of the Chinese Academy of Sciences(KSCX2-EW-J-6)the State Key Laboratory of Crop Stress Biology for Arid Areas,Northwest A&F University
文摘The lichen-forming fungus was isolated from the desert lichen Endocarpon pusillum that is extremely drought resistant.To understand the molecular mechanisms of drought resistance in the fungus,we employed RNA-seq and quantitative real-time PCR to compare and characterize the differentially expressed genes in pure culture at two different water levels and with that in desiccated lichen.The comparative transcriptome analysis indicated that a total of 1781 genes were differentially expressed between samples cultured under normal and PEG-induced drought stress conditions.Similar to those in drought resistance plants and non-lichenized fungi,the common drought-resistant mechanisms were differentially expressed in E.pusillum.However,the expression change of genes involved in osmotic regulation in E.pusillum is different,which might be the evidence for the feature of drought adaptation.Interestingly,different from other organisms,some genes involved in drought adaption mechanisms showed significantly different expression patterns between the presence and absence of drought stress in E.pusillum.The expression of 23 candidate stress responsive genes was further confirmed by quantitative real-time PCR using dehydrated E.pusillum lichen thalli.This study provides a valuable resource for future research on lichen-forming fungi and shall facilitate future functional studies of the specific genes related to drought resistance.
