Shifts in tree species and their mycorrhizal associations driven by global change play key roles in biogeochemical cycles. In this paper, we proposed a framework of the mycorrhizal-associated nutrient economy(MANE), a...Shifts in tree species and their mycorrhizal associations driven by global change play key roles in biogeochemical cycles. In this paper, we proposed a framework of the mycorrhizal-associated nutrient economy(MANE), and tested it using nutrient addition experiments conducted in two tropical rainforests. We selected two tropical rainforests dominated by arbuscular mycorrhizal(AM) and ectomycorrhizal(ECM) trees, and established eighteen20 m×20 m plots in each rainforest. Six nitrogen(N) and phosphorus(P) addition treatments were randomly distributed in each rainforest with three replicates. We examined the differences in soil carbon(C) and nutrient cycling, plant and litter productivity between the two rainforests and their responses to 10-year inorganic N and P additions. We also quantified the P pools of plants, roots, litter, soil and microbes in the two rainforests. Overall,distinct MANE frameworks were applicable for tropical rainforests, in which soil C, N and P were cycled primarily in an inorganic form in the AM-dominated rainforest, whereas they were cycled in an organic form in the ECMdominated rainforest. Notably, the effects of mycorrhizal types on soil P cycling were stronger than those on C and N cycling. The intensified N and P deposition benefited the growth of AM-dominated rainforests instead of ECMdominated rainforests. Our findings underpin the key role of mycorrhizal types in regulating biogeochemical processes, and have important implications for predicting the ecological consequences of global changes.展开更多
Camptotheca acuminata seeds were sown in sterilized sands in the greenhouse in February of 2005. After 90-day growth, seedlings were inoculated with three species of arbuscular mycorrhizal fungi （AMF）, Acaulospora m...Camptotheca acuminata seeds were sown in sterilized sands in the greenhouse in February of 2005. After 90-day growth, seedlings were inoculated with three species of arbuscular mycorrhizal fungi （AMF）, Acaulospora mellea, Glomus diaphanum and Sclerocystis sinuosa.. The height, biomass, and absorptions of nitrogen and phosphorus of C. acuminata seedlings inoculated with AMF were investigated. The results showed that the formation of AM promoted the height growth and biomass accumulation of seedlings significantly and improved the absorption of phosphorus in seedlings. The height and biomass of mycorrhizal seedlings were 1.2 and 1.6 times higher than those of the non-mycorrhizal seedlings. The absorption of nitrogen was less influenced by the formation of AM. The nitrogen content in mycorrhizal seedling was equal to that of non-mycorrhizal seedlings. Compared with non-mycorrhizal seedlings, the nitrogen content of mycorrhizal seedlings inoculated with A. mellea changed considerably in the root, stem and leaves. The difference in nitrogen content was not significant between mycorrhizal seedlings inoculated with G. diaphanum and S. sinuosa. The AM formation stimulated the absorption of phosphorus, especially in roots, and also changed the allocation of nitrogen and phosphorus in different organs of seedlings. Compared with non-mycorrhizal seedlings, the ratio of nitrogen and phosphorus in mycorrhizal roots increased, but reduced in stem and leaves.展开更多
Arbutoid mycorrhizae were synthesized between adult se- lected clones of Arbutus unedo L. and Pisolithus arhizus. Two micro- propagated clones were tested： ALl, in vitro and C1 （acclimatized plants） in nursery and ...Arbutoid mycorrhizae were synthesized between adult se- lected clones of Arbutus unedo L. and Pisolithus arhizus. Two micro- propagated clones were tested： ALl, in vitro and C1 （acclimatized plants） in nursery and later in a field trial. In vitro, rooted shoots were trans- ferred to test tubes containing the substrate previously inoculated with mycelium cultured on agar. In the nursery, two inoculation treatments were tested （vegetative inocula or dry sporocarps） and compared to con- trol plants. In the field trial, plants from nursery inoculation treatments were compared and an additional control treatment using seedlings was implemented. Plant height was evaluated 4 months later in the nursery and 20 months later in the field trial.展开更多
Arbuscular mycorrhiza （AM） formed between plant roots and fungi is one of the most widespread symbiotic associations in nature. To understand the molecular mechanisms of AM formation, we profiled 30 symbiosis-relate...Arbuscular mycorrhiza （AM） formed between plant roots and fungi is one of the most widespread symbiotic associations in nature. To understand the molecular mechanisms of AM formation, we profiled 30 symbiosis-related genes expressed in Amorpha fruticosa roots colonized by Glomus mosseae and in non-mycorrhizal roots at different stages using differential-display RT-PCR （DDRT-PCR）. The expressed genes were confirmed by reverse Northern blotting. Eleven fragments were sequenced and putatively identified by homologous alignment. Of the eleven AM-related genes, five were obtained at the early-stage of plant-fungus interaction and six at the later stage. Three expressed se-quence tag （ESTs） sequences were found to originate from the fungi and eight from the host plant by use of PCR evaluation of gDNA of both plant and fungi. The target genes included an ATP-binding cassette sub-family transporter gene, a transposon-insertion display band, and a photosynthesis-related gene. The results provided information on the molecular mechanisms underlying the development of mycorrhizal sym-biosis between woody plants and AM fungi.展开更多
Biodiversity of arbuscular mycorrhizal colonization and spore population was investigated in different agroforestry trees and crop species collected from different locations of Dinajpur district of Bangladesh. Roots a...Biodiversity of arbuscular mycorrhizal colonization and spore population was investigated in different agroforestry trees and crop species collected from different locations of Dinajpur district of Bangladesh. Roots and rhizosphere soils of Albizia procera Benth., Capsicum frutescens L, Curcuma domestica Vahl., Dalbergia sissoo Roxb. and Swietenia macrophylla King. from Dashmail; C. domestica, D. sissoo, Eucalyptus camaldulensis Dehnn., Gmelina arborea （Roxb） DC and Oryza sativa L. from Kantaji and C. domestica, D. sissoo, Litchi chinensis Sonn. and O. sativa from Ramsagar were collected. Roots and soils were assessed following standard methods. The range of AM colonization was recorded 36%-79% from Dashmail. The highest AM colonization was recorded in C. frutescens （79%） and the lowest was in C. domestica （36%）. The range of colonization was recorded as 33%-70% from Kantaji. The highest AM colonization was recorded in G. arborea （70%） and the lowest was in O. sativa （33%）. The range of AM colonization was recorded as 35%-70% from Ramsagar. The highest AM colonization was recorded in D. sissoo （70%） and the lowest was in O. sativa （35%）. Arbuscular mycorrhizal spore population varied from 54 to 140/100g dry soil in the soils from Dashmail. The highest was in the soils of D. sissoo （140） and the lowest was in C. domestica （54）. The spore population varied from 63 to 221 in Kantaji. The highest was in G. arborea （221） and the lowest was in O. sativa （63）. The range population in Ramsagar varied from 69 to 160. The highest was recorded in D. sissoo （160） and the lowest was in L. chinensis （69）. No significant relationship of soil pH and soil OM with AM colonization and with spore population was observed. Simpson＇s index of diversity （Ds） and Shannon＇s index of diversity- （Hs） were highest in the soil of D. sissoo from Kantaji and the lowest in the soils of O. sativa from Ramsagar. Biodiversity of AM colonization, spore population and the distribution of AM fungi in the rhizosphere soils of different agroforestry plants indicated the occurrence of AM fungi, mycotrophic nature of the trees and crop species, contribution and necessity of AM fungi and the AM dependence of the agroforestry plants growing in Dinajpur district of Bangladesh.展开更多
Arbscular mycorrhiza(AM),a symbiosis between plants and members of fungi Glomeromycota,improves the resistance,nutrition and material metabolism of plant.Arbuscules generated by symbiotic development,is the main site ...Arbscular mycorrhiza(AM),a symbiosis between plants and members of fungi Glomeromycota,improves the resistance,nutrition and material metabolism of plant.Arbuscules generated by symbiotic development,is the main site of nutrient exchange and genetic material recombination,resulting in physiological changes and gene expression regulation.AM regulates pathogenesis-related protein(PRs) genes and antioxidant enzyme genes against biotic and abiotic stresses.Nutrient exchange induced by AM is directly involved in uptake,transformation and utilization of nutrient elements in plants.Importantly,transporter genes play an important role in phosphate,nitrogen and carbon acquisition.In AM interactions,phosphate transporter(PT) genes,from both arbuscular mycorrhizal fungi and plant root,are induced and there product promote phosphate acquisition;increasing expression of ammonium transporter(AMT) genes and arginine biosynthesis/degradation enzyme genes is in charge of nitrogen acquisition;and promotion mechanism of carbon acquisition is involved in up-regulation of sugar transporter genes.In addition,secondary metabolites,functioned as signal moleculars and defense compounds,are increased with development of AM symbiont by up-regulating related synthetic genes based on different promotion mechanism.Taken together,molecular regulation of plant and arbuscular mycorrhizal fungi,induced by infection process,stimulate plant nutrient acquisition and resist to biotic/abiotic stress.展开更多
以白三叶为材料,在盆栽条件下研究丛枝菌根真菌粘屑多样孢囊霉（Diversispora spurca）、地表球囊霉（Glomus versiforme）和隐类球囊霉（Paraglom us occultum）对其叶绿素含量、根系构型及组织蔗糖和葡萄糖含量的影响.结果表明,接种8...以白三叶为材料,在盆栽条件下研究丛枝菌根真菌粘屑多样孢囊霉（Diversispora spurca）、地表球囊霉（Glomus versiforme）和隐类球囊霉（Paraglom us occultum）对其叶绿素含量、根系构型及组织蔗糖和葡萄糖含量的影响.结果表明,接种85 d后白三叶根系菌根侵染率为66.80％～82.51％.3种丛枝菌根真菌都增加地上部、地下部和植株总干物质量,其中地表球囊霉的效果最显著.接种丛枝菌根真菌处理也显著地改善根系构型参数,如长度、投影面积、表面积、体积、根尖数、分支数和交叉数,但因真菌种类而异,其中地表球囊霉的效果最明显.丛枝菌根真菌接种同时显著提高叶绿素含量,达36％～58％,也显著增加叶片和根系的蔗糖和葡萄糖含量,除地表球囊霉侵染的根系蔗糖含量下降外.菌根侵染率与叶片葡萄糖（r=0.852,P＜0.01）、叶片蔗糖（r=0.722,P＜0.01）和根系葡萄糖（r=0.884,P＜0.01）均呈极显著正相关关系.文章讨论了丛枝菌根-糖-根系构型三者的关联.展开更多
基金supported by the National Natural Science Foundation of China(No.31988102)National Key Research and Development Program of China(No.2017YFC0503906)。
文摘Shifts in tree species and their mycorrhizal associations driven by global change play key roles in biogeochemical cycles. In this paper, we proposed a framework of the mycorrhizal-associated nutrient economy(MANE), and tested it using nutrient addition experiments conducted in two tropical rainforests. We selected two tropical rainforests dominated by arbuscular mycorrhizal(AM) and ectomycorrhizal(ECM) trees, and established eighteen20 m×20 m plots in each rainforest. Six nitrogen(N) and phosphorus(P) addition treatments were randomly distributed in each rainforest with three replicates. We examined the differences in soil carbon(C) and nutrient cycling, plant and litter productivity between the two rainforests and their responses to 10-year inorganic N and P additions. We also quantified the P pools of plants, roots, litter, soil and microbes in the two rainforests. Overall,distinct MANE frameworks were applicable for tropical rainforests, in which soil C, N and P were cycled primarily in an inorganic form in the AM-dominated rainforest, whereas they were cycled in an organic form in the ECMdominated rainforest. Notably, the effects of mycorrhizal types on soil P cycling were stronger than those on C and N cycling. The intensified N and P deposition benefited the growth of AM-dominated rainforests instead of ECMdominated rainforests. Our findings underpin the key role of mycorrhizal types in regulating biogeochemical processes, and have important implications for predicting the ecological consequences of global changes.
基金This paper was supported by the Heilongjiang Province Foundation for Distinguished Youth Scholars (JC-02-11)
文摘Camptotheca acuminata seeds were sown in sterilized sands in the greenhouse in February of 2005. After 90-day growth, seedlings were inoculated with three species of arbuscular mycorrhizal fungi （AMF）, Acaulospora mellea, Glomus diaphanum and Sclerocystis sinuosa.. The height, biomass, and absorptions of nitrogen and phosphorus of C. acuminata seedlings inoculated with AMF were investigated. The results showed that the formation of AM promoted the height growth and biomass accumulation of seedlings significantly and improved the absorption of phosphorus in seedlings. The height and biomass of mycorrhizal seedlings were 1.2 and 1.6 times higher than those of the non-mycorrhizal seedlings. The absorption of nitrogen was less influenced by the formation of AM. The nitrogen content in mycorrhizal seedling was equal to that of non-mycorrhizal seedlings. Compared with non-mycorrhizal seedlings, the nitrogen content of mycorrhizal seedlings inoculated with A. mellea changed considerably in the root, stem and leaves. The difference in nitrogen content was not significant between mycorrhizal seedlings inoculated with G. diaphanum and S. sinuosa. The AM formation stimulated the absorption of phosphorus, especially in roots, and also changed the allocation of nitrogen and phosphorus in different organs of seedlings. Compared with non-mycorrhizal seedlings, the ratio of nitrogen and phosphorus in mycorrhizal roots increased, but reduced in stem and leaves.
基金supported by a PhD fellowship (SFRH/BD/37170/2007)from the Portuguese Foundation for Science and Technology(FCT)
文摘Arbutoid mycorrhizae were synthesized between adult se- lected clones of Arbutus unedo L. and Pisolithus arhizus. Two micro- propagated clones were tested： ALl, in vitro and C1 （acclimatized plants） in nursery and later in a field trial. In vitro, rooted shoots were trans- ferred to test tubes containing the substrate previously inoculated with mycelium cultured on agar. In the nursery, two inoculation treatments were tested （vegetative inocula or dry sporocarps） and compared to con- trol plants. In the field trial, plants from nursery inoculation treatments were compared and an additional control treatment using seedlings was implemented. Plant height was evaluated 4 months later in the nursery and 20 months later in the field trial.
基金supported by National Natural Science Foundation of China(31070576 and 31270535)Natural Science Foundation of Heilongjiang Province of China(No.ZD201206)+1 种基金Excellent Youth Foundation of Heilongjiang Province of China(No.JC201306)High-level Talents Support Program of Heilongjiang University(Ecological Restoration Team)
文摘Arbuscular mycorrhiza （AM） formed between plant roots and fungi is one of the most widespread symbiotic associations in nature. To understand the molecular mechanisms of AM formation, we profiled 30 symbiosis-related genes expressed in Amorpha fruticosa roots colonized by Glomus mosseae and in non-mycorrhizal roots at different stages using differential-display RT-PCR （DDRT-PCR）. The expressed genes were confirmed by reverse Northern blotting. Eleven fragments were sequenced and putatively identified by homologous alignment. Of the eleven AM-related genes, five were obtained at the early-stage of plant-fungus interaction and six at the later stage. Three expressed se-quence tag （ESTs） sequences were found to originate from the fungi and eight from the host plant by use of PCR evaluation of gDNA of both plant and fungi. The target genes included an ATP-binding cassette sub-family transporter gene, a transposon-insertion display band, and a photosynthesis-related gene. The results provided information on the molecular mechanisms underlying the development of mycorrhizal sym-biosis between woody plants and AM fungi.
文摘Biodiversity of arbuscular mycorrhizal colonization and spore population was investigated in different agroforestry trees and crop species collected from different locations of Dinajpur district of Bangladesh. Roots and rhizosphere soils of Albizia procera Benth., Capsicum frutescens L, Curcuma domestica Vahl., Dalbergia sissoo Roxb. and Swietenia macrophylla King. from Dashmail; C. domestica, D. sissoo, Eucalyptus camaldulensis Dehnn., Gmelina arborea （Roxb） DC and Oryza sativa L. from Kantaji and C. domestica, D. sissoo, Litchi chinensis Sonn. and O. sativa from Ramsagar were collected. Roots and soils were assessed following standard methods. The range of AM colonization was recorded 36%-79% from Dashmail. The highest AM colonization was recorded in C. frutescens （79%） and the lowest was in C. domestica （36%）. The range of colonization was recorded as 33%-70% from Kantaji. The highest AM colonization was recorded in G. arborea （70%） and the lowest was in O. sativa （33%）. The range of AM colonization was recorded as 35%-70% from Ramsagar. The highest AM colonization was recorded in D. sissoo （70%） and the lowest was in O. sativa （35%）. Arbuscular mycorrhizal spore population varied from 54 to 140/100g dry soil in the soils from Dashmail. The highest was in the soils of D. sissoo （140） and the lowest was in C. domestica （54）. The spore population varied from 63 to 221 in Kantaji. The highest was in G. arborea （221） and the lowest was in O. sativa （63）. The range population in Ramsagar varied from 69 to 160. The highest was recorded in D. sissoo （160） and the lowest was in L. chinensis （69）. No significant relationship of soil pH and soil OM with AM colonization and with spore population was observed. Simpson＇s index of diversity （Ds） and Shannon＇s index of diversity- （Hs） were highest in the soil of D. sissoo from Kantaji and the lowest in the soils of O. sativa from Ramsagar. Biodiversity of AM colonization, spore population and the distribution of AM fungi in the rhizosphere soils of different agroforestry plants indicated the occurrence of AM fungi, mycotrophic nature of the trees and crop species, contribution and necessity of AM fungi and the AM dependence of the agroforestry plants growing in Dinajpur district of Bangladesh.
基金financed by the Doctoral Foundation of Ministry of Education of China(20110101110094)
文摘Arbscular mycorrhiza(AM),a symbiosis between plants and members of fungi Glomeromycota,improves the resistance,nutrition and material metabolism of plant.Arbuscules generated by symbiotic development,is the main site of nutrient exchange and genetic material recombination,resulting in physiological changes and gene expression regulation.AM regulates pathogenesis-related protein(PRs) genes and antioxidant enzyme genes against biotic and abiotic stresses.Nutrient exchange induced by AM is directly involved in uptake,transformation and utilization of nutrient elements in plants.Importantly,transporter genes play an important role in phosphate,nitrogen and carbon acquisition.In AM interactions,phosphate transporter(PT) genes,from both arbuscular mycorrhizal fungi and plant root,are induced and there product promote phosphate acquisition;increasing expression of ammonium transporter(AMT) genes and arginine biosynthesis/degradation enzyme genes is in charge of nitrogen acquisition;and promotion mechanism of carbon acquisition is involved in up-regulation of sugar transporter genes.In addition,secondary metabolites,functioned as signal moleculars and defense compounds,are increased with development of AM symbiont by up-regulating related synthetic genes based on different promotion mechanism.Taken together,molecular regulation of plant and arbuscular mycorrhizal fungi,induced by infection process,stimulate plant nutrient acquisition and resist to biotic/abiotic stress.
