Pub Date : 2023-02-20DOI: 10.1639/0007-2745-126.1.090
Joseph Di Meglio, T. Goward
Abstract. Sticta is a subcosmopolitan, predominantly epiphytic lichenizing fungal genus characteristic of open sites in humid late-successional ecosystems. Recent molecular analysis has shown that the laminally isidiate species S. fuliginosa, long assumed to be well delimited, encompasses >20 phylospecies which, taken together, constitute the S. fuliginosa morphodeme. Here we elucidate the northwestern North American members of this morphodeme based on a rich sampling from throughout the Pacific Northwest regions of the U.S.A. and Canada: Alaska, British Columbia, California, Oregon and Washington. Our results support recognition of five species, three of which – S. arenosella sp. nov., S. fasciculata sp. nov. and S. torii – appear to be endemic. Of the remainder, S. globulifuliginosa was described from Colombia, while S. gretae sp. nov. occurs also in the Canary Islands and China. Two of our new species – S. fasciculata and S. gretae comprise a new phylogenetic lineage and is referred to as the S. gretae clade. New taxonomically informative thallus characters are introduced and a key to the genus Sticta in northwest North America is provided.
{"title":"Resolving the Sticta fuliginosa Morphodeme (Lichenized Ascomycota: Peltigeraceae) in Northwestern North America","authors":"Joseph Di Meglio, T. Goward","doi":"10.1639/0007-2745-126.1.090","DOIUrl":"https://doi.org/10.1639/0007-2745-126.1.090","url":null,"abstract":"Abstract. Sticta is a subcosmopolitan, predominantly epiphytic lichenizing fungal genus characteristic of open sites in humid late-successional ecosystems. Recent molecular analysis has shown that the laminally isidiate species S. fuliginosa, long assumed to be well delimited, encompasses >20 phylospecies which, taken together, constitute the S. fuliginosa morphodeme. Here we elucidate the northwestern North American members of this morphodeme based on a rich sampling from throughout the Pacific Northwest regions of the U.S.A. and Canada: Alaska, British Columbia, California, Oregon and Washington. Our results support recognition of five species, three of which – S. arenosella sp. nov., S. fasciculata sp. nov. and S. torii – appear to be endemic. Of the remainder, S. globulifuliginosa was described from Colombia, while S. gretae sp. nov. occurs also in the Canary Islands and China. Two of our new species – S. fasciculata and S. gretae comprise a new phylogenetic lineage and is referred to as the S. gretae clade. New taxonomically informative thallus characters are introduced and a key to the genus Sticta in northwest North America is provided.","PeriodicalId":55319,"journal":{"name":"Bryologist","volume":"126 1","pages":"90 - 110"},"PeriodicalIF":0.9,"publicationDate":"2023-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47453890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-20DOI: 10.1639/0007-2745-126.1.111
J. Lendemer, Jason P. Hollinger
Abstract. Schadonia saulskellyana is described as new to science based on material from the southern Appalachian Mountains in the eastern United States. The species appears to be endemic to the region and mostly restricted to the bark of conifers. It is particularly abundant and frequent in the imperiled high-elevation spruce-fir forests of the region. The new species is distinguished from its congeners by its corticolous habit, minutely areolate thallus with areoles that erupt into soralia which dissolve the areoles and give the appearance of a leprose crust, epruinose, dark brown-black apothecia with a brown hypothecium, and monosporous asci with large, muriform ascospores. It is also compared with other genera of Pilocarpaceae, particularly Calopadia. Lopadium disciforme, a superficially similar species is also compared to the new species and photographs, as well as a distribution map for eastern North America, are provided for that species.
{"title":"Schadonia saulskellyana (Pilocarpaceae; Lichenized Ascomycetes) an unusual new species endemic to the southern Appalachian Mountains of eastern North America","authors":"J. Lendemer, Jason P. Hollinger","doi":"10.1639/0007-2745-126.1.111","DOIUrl":"https://doi.org/10.1639/0007-2745-126.1.111","url":null,"abstract":"Abstract. Schadonia saulskellyana is described as new to science based on material from the southern Appalachian Mountains in the eastern United States. The species appears to be endemic to the region and mostly restricted to the bark of conifers. It is particularly abundant and frequent in the imperiled high-elevation spruce-fir forests of the region. The new species is distinguished from its congeners by its corticolous habit, minutely areolate thallus with areoles that erupt into soralia which dissolve the areoles and give the appearance of a leprose crust, epruinose, dark brown-black apothecia with a brown hypothecium, and monosporous asci with large, muriform ascospores. It is also compared with other genera of Pilocarpaceae, particularly Calopadia. Lopadium disciforme, a superficially similar species is also compared to the new species and photographs, as well as a distribution map for eastern North America, are provided for that species.","PeriodicalId":55319,"journal":{"name":"Bryologist","volume":"126 1","pages":"111 - 128"},"PeriodicalIF":0.9,"publicationDate":"2023-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41786910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-06DOI: 10.1639/0007-2745-126.1.052
R. Ritchie, Suhailar Sma-air
Abstract. Despite their global distribution moss physiology is not well understood, particularly in tropical environments. Photosynthetic Electron Transport Rate (ETR) of Hyophila involuta was measured using PAM technology. The plants were growing in a heavily shaded habitat with irregular sunflecks of full sunlight. Two models were used for estimating photosynthetic electron transport (ETR), the Waiting-in-Line and Eilers-Peeters models. Both take photoinhibition into account and gave similar results. The population studied was growing on bricks and stonework and so periodically dried out. The same species is sometimes found in waterfall environments where it is semi-aquatic. ETRmax was low at dawn, increased to an early morning maxima and then decreased during the course of the day, partially reversed by rainstorms. Mid-morning (10:30 solar time): Eopt ≈ 521 ± 77 µmol photon m–2 s–1 which is higher than might be expected in a shaded sun-fleck environment, ETRmax ≈ 28.3 ± 2.5 µmol e- m–2 s–1 on a projected surface area basis or ≈ 57.7 ± 5.1 (µmol e- g–1 Chl a s–1), photosynthetic efficiency (Alpha, α0) ≈ 0.301 (e- photon–1 g–1 Chl a). Chl a content of Hyophila was ≈ 453 mg Chl a m–2 with Chl b/a ≈ 0.371. The O2 electrode-based respiration rate was R = 6.78 ± 0.698 µmol O2 g–1 Chl a s–1, the ETRmax is roughly equivalent to Gross photosynthesis (Pg) ≈ 14.4 ± 1.28 µmol O2 g–1 Chl a s–1 (4 e-/ O2), so the optimum Pg/R ratio is about 2.12 ± 0.289 and net photosynthesis (Pn) is ≈ 7.62 ± 1.46 µmol O2 g–1 Chl a s–1. Thus even under optimum irradiance net photosynthesis was actually rather low. pH experiments showed that Hyophila used both CO2 & HCO3- inorganic carbon sources, suggesting that a concentrating mechanism (CCM) is present. Hyophila is partially homiochlorophyllous, recovering well from desiccation after 2h of lighted rehydration and recovers more after 24h but lost ≈30% of its Chl a. The moss retained its chlorophyll content if desiccated in the dark. The moss lost ≈ 2/3 of its Chl a during the monsoonal dry season.
{"title":"Photosynthetic electron transport in a tropical moss Hyophila involuta","authors":"R. Ritchie, Suhailar Sma-air","doi":"10.1639/0007-2745-126.1.052","DOIUrl":"https://doi.org/10.1639/0007-2745-126.1.052","url":null,"abstract":"Abstract. Despite their global distribution moss physiology is not well understood, particularly in tropical environments. Photosynthetic Electron Transport Rate (ETR) of Hyophila involuta was measured using PAM technology. The plants were growing in a heavily shaded habitat with irregular sunflecks of full sunlight. Two models were used for estimating photosynthetic electron transport (ETR), the Waiting-in-Line and Eilers-Peeters models. Both take photoinhibition into account and gave similar results. The population studied was growing on bricks and stonework and so periodically dried out. The same species is sometimes found in waterfall environments where it is semi-aquatic. ETRmax was low at dawn, increased to an early morning maxima and then decreased during the course of the day, partially reversed by rainstorms. Mid-morning (10:30 solar time): Eopt ≈ 521 ± 77 µmol photon m–2 s–1 which is higher than might be expected in a shaded sun-fleck environment, ETRmax ≈ 28.3 ± 2.5 µmol e- m–2 s–1 on a projected surface area basis or ≈ 57.7 ± 5.1 (µmol e- g–1 Chl a s–1), photosynthetic efficiency (Alpha, α0) ≈ 0.301 (e- photon–1 g–1 Chl a). Chl a content of Hyophila was ≈ 453 mg Chl a m–2 with Chl b/a ≈ 0.371. The O2 electrode-based respiration rate was R = 6.78 ± 0.698 µmol O2 g–1 Chl a s–1, the ETRmax is roughly equivalent to Gross photosynthesis (Pg) ≈ 14.4 ± 1.28 µmol O2 g–1 Chl a s–1 (4 e-/ O2), so the optimum Pg/R ratio is about 2.12 ± 0.289 and net photosynthesis (Pn) is ≈ 7.62 ± 1.46 µmol O2 g–1 Chl a s–1. Thus even under optimum irradiance net photosynthesis was actually rather low. pH experiments showed that Hyophila used both CO2 & HCO3- inorganic carbon sources, suggesting that a concentrating mechanism (CCM) is present. Hyophila is partially homiochlorophyllous, recovering well from desiccation after 2h of lighted rehydration and recovers more after 24h but lost ≈30% of its Chl a. The moss retained its chlorophyll content if desiccated in the dark. The moss lost ≈ 2/3 of its Chl a during the monsoonal dry season.","PeriodicalId":55319,"journal":{"name":"Bryologist","volume":"126 1","pages":"52 - 68"},"PeriodicalIF":0.9,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45315666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-06DOI: 10.1639/0007-2745-126.1.045
R. Wyatt, I. Odrzykoski, A. Stoneburner
Abstract. One of the two most speciose genera in the Mniaceae, Rhizomnium includes 14 to 16 named taxa with the likelihood that more remain to be described. Our previous research established that R. pseudopunctatum is an allodiploid whose haploid progenitors are R. gracile and R. magnifolium. In the course of that work, we sampled five additional species as possible progenitors. Using isozymes from starch-gel electrophoresis, we screened all eight species to compare levels of genetic variation within species, genetic distances between species, and genetic population structure. Levels of variation are generally lower than for species of Plagiomnium but are similar to those for species of Cinclidium. Relationships of species based on genetic data are mostly congruent with Koponen's (1973) “assumed phylogeny” of Rhizomnium, but there are also some clear conflicts. For example, R. appalachianum is highly divergent from the other three species placed in sect. Macromnium, and R. glabrescens does not seem to fit in sect. Rhizomnium. Genetic distance data, however, do support Koponen & Sun's (2016) recognition of R. chlorophyllosum as a separate species from R. punctatum.
{"title":"Isozyme evidence regarding relationships within Rhizomnium (Mniaceae)","authors":"R. Wyatt, I. Odrzykoski, A. Stoneburner","doi":"10.1639/0007-2745-126.1.045","DOIUrl":"https://doi.org/10.1639/0007-2745-126.1.045","url":null,"abstract":"Abstract. One of the two most speciose genera in the Mniaceae, Rhizomnium includes 14 to 16 named taxa with the likelihood that more remain to be described. Our previous research established that R. pseudopunctatum is an allodiploid whose haploid progenitors are R. gracile and R. magnifolium. In the course of that work, we sampled five additional species as possible progenitors. Using isozymes from starch-gel electrophoresis, we screened all eight species to compare levels of genetic variation within species, genetic distances between species, and genetic population structure. Levels of variation are generally lower than for species of Plagiomnium but are similar to those for species of Cinclidium. Relationships of species based on genetic data are mostly congruent with Koponen's (1973) “assumed phylogeny” of Rhizomnium, but there are also some clear conflicts. For example, R. appalachianum is highly divergent from the other three species placed in sect. Macromnium, and R. glabrescens does not seem to fit in sect. Rhizomnium. Genetic distance data, however, do support Koponen & Sun's (2016) recognition of R. chlorophyllosum as a separate species from R. punctatum.","PeriodicalId":55319,"journal":{"name":"Bryologist","volume":"126 1","pages":"45 - 51"},"PeriodicalIF":0.9,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67382618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-01DOI: 10.1639/0007-2745-126.1.035
W. Sanders, A. de los Ríos
Abstract. Numerous distinct clades of lichen-forming fungi have independently specialized as foliicolous colonists of living leaves in the humid tropics and subtropics. Because of technical difficulties, the anatomy of their minute crustose thalli has not been compared in detail. In the present study, we applied SEM-BSE imaging to sectioned blocks of embedded thalli representing six lecanoralean taxa of foliicolous lichen-forming fungi with unicellular green algal partners. We compared our observations with those obtained in a previous study of foliicolous Gomphillaceae (Ostropales), which utilize a similar type of algal partner. The upper surface of the thalli was a mostly continuous layer of mycobiont hyphae of typical diameter, unlike the largely acellular epilayer found previously in the foliicolous Gomphillaceae. Byssoloma leucoblepharum was exceptional in lacking a covering layer altogether. Thalli were essentially unstratified, with algal symbionts not confined to any distinct layer. Whereas the prothallus of foliicolous Gomphillaceae was derived from the overlying epilayer, in the lecanoralean taxa examined here the prothallus was derived from hyphae continuous with either the upper surface of the thallus or the lower surface, or both. This finding suggests that the prothallus of lichen forming fungi may represent structures of developmentally different origins in different taxa.
{"title":"Structure of foliicolous lichen thalli formed by some common lecanoralean taxa in subtropical leaf communities","authors":"W. Sanders, A. de los Ríos","doi":"10.1639/0007-2745-126.1.035","DOIUrl":"https://doi.org/10.1639/0007-2745-126.1.035","url":null,"abstract":"Abstract. Numerous distinct clades of lichen-forming fungi have independently specialized as foliicolous colonists of living leaves in the humid tropics and subtropics. Because of technical difficulties, the anatomy of their minute crustose thalli has not been compared in detail. In the present study, we applied SEM-BSE imaging to sectioned blocks of embedded thalli representing six lecanoralean taxa of foliicolous lichen-forming fungi with unicellular green algal partners. We compared our observations with those obtained in a previous study of foliicolous Gomphillaceae (Ostropales), which utilize a similar type of algal partner. The upper surface of the thalli was a mostly continuous layer of mycobiont hyphae of typical diameter, unlike the largely acellular epilayer found previously in the foliicolous Gomphillaceae. Byssoloma leucoblepharum was exceptional in lacking a covering layer altogether. Thalli were essentially unstratified, with algal symbionts not confined to any distinct layer. Whereas the prothallus of foliicolous Gomphillaceae was derived from the overlying epilayer, in the lecanoralean taxa examined here the prothallus was derived from hyphae continuous with either the upper surface of the thallus or the lower surface, or both. This finding suggests that the prothallus of lichen forming fungi may represent structures of developmentally different origins in different taxa.","PeriodicalId":55319,"journal":{"name":"Bryologist","volume":"126 1","pages":"35 - 44"},"PeriodicalIF":0.9,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42571411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-20DOI: 10.1639/0007-2745-126.1.001
O. Asher, J. Howieson, J. Lendemer
Abstract. Lichens in the genus Platismatia are common, widespread and were some of the first to be studied by Western taxonomists. However, few molecular phylogenetic studies of Platismatia have been published to date. We present an expanded phylogeny of Platismatia inferred from 60 newly generated ITS sequences and 28 existing publicly available sequences. The new phylogeny confirms the delimitation of P. wheeleri as monophyletic and distinct from the widespread P. glauca, the latter of which was recovered as two separate, highly supported clades, that do not appear to differ in phenotype or biogeography. The western North American endemics P. herrei and P. stenophylla were not recovered as reciprocally monophyletic and may be an example of recent speciation similar to that also hypothesized for Alectoria in the same region. Ancestral state reconstructions of reproductive modes (dominant asexual vs. sexual reproduction; asexual propagule type) suggest that sexual species like P. tuckermanii can evolve from primarily asexual ancestors. Evaluation of species distributions suggests that reproductive mode may be related to range size. These data suggest that Platismatia could serve as a model for future studies on reproductive mode, biogeography and speciation in lichens.
{"title":"A new perspective on the macrolichen genus Platismatia (Parmeliaceae, Ascomycota) based on molecular and phenotypic data","authors":"O. Asher, J. Howieson, J. Lendemer","doi":"10.1639/0007-2745-126.1.001","DOIUrl":"https://doi.org/10.1639/0007-2745-126.1.001","url":null,"abstract":"Abstract. Lichens in the genus Platismatia are common, widespread and were some of the first to be studied by Western taxonomists. However, few molecular phylogenetic studies of Platismatia have been published to date. We present an expanded phylogeny of Platismatia inferred from 60 newly generated ITS sequences and 28 existing publicly available sequences. The new phylogeny confirms the delimitation of P. wheeleri as monophyletic and distinct from the widespread P. glauca, the latter of which was recovered as two separate, highly supported clades, that do not appear to differ in phenotype or biogeography. The western North American endemics P. herrei and P. stenophylla were not recovered as reciprocally monophyletic and may be an example of recent speciation similar to that also hypothesized for Alectoria in the same region. Ancestral state reconstructions of reproductive modes (dominant asexual vs. sexual reproduction; asexual propagule type) suggest that sexual species like P. tuckermanii can evolve from primarily asexual ancestors. Evaluation of species distributions suggests that reproductive mode may be related to range size. These data suggest that Platismatia could serve as a model for future studies on reproductive mode, biogeography and speciation in lichens.","PeriodicalId":55319,"journal":{"name":"Bryologist","volume":"126 1","pages":"1 - 18"},"PeriodicalIF":0.9,"publicationDate":"2023-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42442485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-20DOI: 10.1639/0007-2745-126.1.019
G. Paz-Bermúdez, P. Divakar, J. Etayo, Elena Araujo
Abstract. The importance of the COI lichen herbarium is increased by the results shown here. Forty-seven taxa are reported from Africa, forty-three from Angola and seven from Mozambique. Four species are new to Africa, 30 to Angola and 3 to Mozambique. Two species are described as new to science: Parmotrema carballalianum and Sclerococcum parmotrematis, a lichenicolous fungus living on the former. A key to all known lichenicolous species of Sclerococcum growing on Parmelia s.l. is provided.
{"title":"The lichen collection from Angola and Mozambique in COI (Coimbra, Portugal)","authors":"G. Paz-Bermúdez, P. Divakar, J. Etayo, Elena Araujo","doi":"10.1639/0007-2745-126.1.019","DOIUrl":"https://doi.org/10.1639/0007-2745-126.1.019","url":null,"abstract":"Abstract. The importance of the COI lichen herbarium is increased by the results shown here. Forty-seven taxa are reported from Africa, forty-three from Angola and seven from Mozambique. Four species are new to Africa, 30 to Angola and 3 to Mozambique. Two species are described as new to science: Parmotrema carballalianum and Sclerococcum parmotrematis, a lichenicolous fungus living on the former. A key to all known lichenicolous species of Sclerococcum growing on Parmelia s.l. is provided.","PeriodicalId":55319,"journal":{"name":"Bryologist","volume":"126 1","pages":"19 - 34"},"PeriodicalIF":0.9,"publicationDate":"2023-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47256371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-27DOI: 10.1639/0007-2745-125.4.602
M. Marschall, Szidónia Sütő
Abstract. Following 5 different rates of 1-week desiccation to which Porella platyphylla (a desiccation-tolerant leafy liverwort) was subjected, physiological recovery upon rehydration (after 1 h, 24 h, 48 h) in light was monitored by cytological, photosynthetic (e-transport rate, photoprotective mechanisms), and other metabolic parameters using nuclear- and chloroplast-encoded protein synthesis inhibitors and a violaxanthin cycle inhibitor (DTT: dithiothreitol). Desiccation tolerance is mainly constitutive in P. platyphylla, allowing survival of rapid drying, and employs an active rehydration-induced repair and recovery mechanism. Following 24 hours of rehydration after the one-week dehydration in laboratory air (∼35% relative humidity /RH/), the chloroplasts had an irregular round shape. The recovery within 1 h of the thylakoid-function-related photosynthetic processes was extremely fast and independent of protein synthesis, while the overall recovery (except plants dried up at 76% RH, which depended on protein synthesis only to a limited extent) required de novo protein synthesis during rewetting. During the course of rehydration protein synthesis affects rehydrin expression, osmolite and general carbohydrate metabolism, the main repair and antioxidant mechanisms. Recovery was the best in samples dried up at 76% RH. Membrane permeability increased upon rehydration following 1-week dehydration. Normal membrane function recovered after 24 h (max. 48 h), except in plants that suffered drastic dehydration. Total protein content of plants dried under different conditions and of samples taken during recovery was generally lower than in the control plants at full turgor. The xanthophyll cycle has a great importance during the recovery in light; we confirmed the existence of a greater zeaxanthin-dependent and a smaller zeaxanthin-insensitive NPQ (nonphotochemical quenching). Plants dried under more favorable conditions had better light protection. The highest values of the osmotic potential belonged to the plants subjected to intense dehydration. Total soluble carbohydrate content was well-balanced and seemed to be unchanged following the different treatments. There was a significant increase in proline, while total fructan showed lower values at different degrees of 1-week desiccation. The cytoplasmic protein synthesis is likely to be involved in the change of the fructan content during rehydration.
{"title":"Effects of desiccation rate and inhibition of protein synthesis and the violaxanthin cycle on the rewetting recovery of Porella platyphylla","authors":"M. Marschall, Szidónia Sütő","doi":"10.1639/0007-2745-125.4.602","DOIUrl":"https://doi.org/10.1639/0007-2745-125.4.602","url":null,"abstract":"Abstract. Following 5 different rates of 1-week desiccation to which Porella platyphylla (a desiccation-tolerant leafy liverwort) was subjected, physiological recovery upon rehydration (after 1 h, 24 h, 48 h) in light was monitored by cytological, photosynthetic (e-transport rate, photoprotective mechanisms), and other metabolic parameters using nuclear- and chloroplast-encoded protein synthesis inhibitors and a violaxanthin cycle inhibitor (DTT: dithiothreitol). Desiccation tolerance is mainly constitutive in P. platyphylla, allowing survival of rapid drying, and employs an active rehydration-induced repair and recovery mechanism. Following 24 hours of rehydration after the one-week dehydration in laboratory air (∼35% relative humidity /RH/), the chloroplasts had an irregular round shape. The recovery within 1 h of the thylakoid-function-related photosynthetic processes was extremely fast and independent of protein synthesis, while the overall recovery (except plants dried up at 76% RH, which depended on protein synthesis only to a limited extent) required de novo protein synthesis during rewetting. During the course of rehydration protein synthesis affects rehydrin expression, osmolite and general carbohydrate metabolism, the main repair and antioxidant mechanisms. Recovery was the best in samples dried up at 76% RH. Membrane permeability increased upon rehydration following 1-week dehydration. Normal membrane function recovered after 24 h (max. 48 h), except in plants that suffered drastic dehydration. Total protein content of plants dried under different conditions and of samples taken during recovery was generally lower than in the control plants at full turgor. The xanthophyll cycle has a great importance during the recovery in light; we confirmed the existence of a greater zeaxanthin-dependent and a smaller zeaxanthin-insensitive NPQ (nonphotochemical quenching). Plants dried under more favorable conditions had better light protection. The highest values of the osmotic potential belonged to the plants subjected to intense dehydration. Total soluble carbohydrate content was well-balanced and seemed to be unchanged following the different treatments. There was a significant increase in proline, while total fructan showed lower values at different degrees of 1-week desiccation. The cytoplasmic protein synthesis is likely to be involved in the change of the fructan content during rehydration.","PeriodicalId":55319,"journal":{"name":"Bryologist","volume":"125 1","pages":"602 - 625"},"PeriodicalIF":0.9,"publicationDate":"2022-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41838699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-27DOI: 10.1639/0007-2745-125.4.626
J. Atwood, W. Buck, J. Brinda
; ‘‘ This research was conducted on September 2012 – May 2013 by purposive sampling method. Based on this research shown that can be found 10 species of mosses, consist of 6 species can be classified to be Marchanticae, 2 species grouped to Anthocerotae, and 2 species to be Musci
{"title":"Recent literature on bryophytes — 125(4)","authors":"J. Atwood, W. Buck, J. Brinda","doi":"10.1639/0007-2745-125.4.626","DOIUrl":"https://doi.org/10.1639/0007-2745-125.4.626","url":null,"abstract":"; ‘‘ This research was conducted on September 2012 – May 2013 by purposive sampling method. Based on this research shown that can be found 10 species of mosses, consist of 6 species can be classified to be Marchanticae, 2 species grouped to Anthocerotae, and 2 species to be Musci","PeriodicalId":55319,"journal":{"name":"Bryologist","volume":"125 1","pages":"626 - 648"},"PeriodicalIF":0.9,"publicationDate":"2022-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47819695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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