The last decade has revealed an unexpected fungal diversity associated with natural rocks,often collected in environments influenced by harsh climatic conditions.Yet the phylogenetic affiliations and the taxonomy of m...The last decade has revealed an unexpected fungal diversity associated with natural rocks,often collected in environments influenced by harsh climatic conditions.Yet the phylogenetic affiliations and the taxonomy of many of these extreme fungi,mainly within Dothideomycetes,the largest class of Ascomycota,have only partially been described.In the present study we confirm that most rock inhabiting-fungi(RIF)are highly polyphyletic among Dothideomycetidae,mainly within the order Capnodiales,an order otherwise incorporating several families of major plant pathological importance.Novel taxa were identified within the two major and distinct clades of Teratosphaeriaceae,both comprising meristematic black fungi.Thirty one novel species and 13 new genera are proposed,based on ITS and partial nucLSU,RPB2 and BT2 sequences.展开更多
Microtubule arrays in prothalli large-vacuolated and meristematic dividing cells of the fern Dryopteris crassirhizoma Nakai were studied using Steedman's wax, indirect immunofluorescence labelling and confocal las...Microtubule arrays in prothalli large-vacuolated and meristematic dividing cells of the fern Dryopteris crassirhizoma Nakai were studied using Steedman's wax, indirect immunofluorescence labelling and confocal laser scanning microscopy. Results showed that the use of high paraformaldehyde concentration (8%) allowed good fixation of prothallus cells, which are characterized by numerous (meristematic cells) and big (large-vacuolated cells) vacuoles. Results also plead for the efficiency of Steedman's wax embedding method in: (1) avoiding excessive use of enzyme for digesting cell wall in the process of the microtubule cytoskeleton labelling, (2) minimizing the autofluorescence effect in cells through utilization of alcohol in sample dehydration, and (3) permitting a clear visualization of microtubule patterns during the cell mitosis. Steedman's wax, coupled with immunofluorescence labelling and confocal laser scanning microscopy techniques, allows a good investigation of cell division process in plants by using simple multicellular organisms such as fern prothalli.展开更多
Callus and suspension cells culture of Kaempferia parviflora was successfully established. Meristematic shoots can be used for utilization of plant cell biosynthetic capabilities for obtaining useful products from val...Callus and suspension cells culture of Kaempferia parviflora was successfully established. Meristematic shoots can be used for utilization of plant cell biosynthetic capabilities for obtaining useful products from valuable medicinal plant to meet out the pharmaceutical demand and also for studying the metabolism. The medium containing combination of 0.2 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.2 mg/L napthyleneacetic acid (NAA) promoted the highest callus induction at 20%. Transferring the initiated callus on the medium with 1 mg/L 2,4-D enhanced the proliferation rate up to maximum fresh weight of 6.71 gm. Growth curve of cultured cells revealed that the cells continued to grow until 50 days of culture and showed the highest peak (fresh weight) at 40 days in all different initial weight tested ( 0.2, 0.5 and 1.0 gram). Isolated embryogenic callus was found to produce the highest in weight when suspended in liquid medium supplemented with 1 mg/L 2,4-D at 110 rpm resulted 13.5 gram fresh weight and 1080 mg dry weight.展开更多
Nitric oxide(NO)is a gasotransmitter-diffusible signaling molecule that is critical across organisms.In plants,NO plays an important function in growth and development,senescence,and the response to abiotic and biotic...Nitric oxide(NO)is a gasotransmitter-diffusible signaling molecule that is critical across organisms.In plants,NO plays an important function in growth and development,senescence,and the response to abiotic and biotic stress(Domingos et al.,2015).Our understanding of the mechanism for NO biosynthesis in plants is limited and centered around the nitrate reductase pathway.Two known NR-encoding genes in Arabidopsis thaliana,NIA1/2,are active in leaves and meristematic tissue(Olas and Wahl,2019),independently regulated in a tissue-dependent manner(Vidal et al.,2015),and required for NO synthesis(Chen et al.,2016).Non-coding RNA species,i.e.,antisense,long intergenic,and sequences processed into small microRNAs/small interfering RNAs(siRNAs)can be potent regulators of gene expression in plants(Traubenik et al.,2024).Previous work discovered two non-coding species originating from the NIA1/2 loci including a 22-nt siRNA(Wu et al.,2020)as well as an antisense RNA(asRNA)from the 3′UTR(Chekanova et al.,2007).The small siRNA derived from the NIA1/2 loci was found to restrain NIA1/2 translation,ultimately inhibiting plant growth and enhancing the stress response(Wu et al.,2020).How these long non-coding species specifically,as NIA1/2,regulate their respective protein-coding sense strands was not understood.In mammalian studies,a similar type of induced NO synthase(iNOS)protein has been shown to be regulated by its asRNA transcribed from the 3′UTR.展开更多
A new cell engineering technique (L. B. technique) was established in our Lab. At first, the physical and chemical methods were used to facilitate the reestablishment of intercellular contacts and plasmodesma channels...A new cell engineering technique (L. B. technique) was established in our Lab. At first, the physical and chemical methods were used to facilitate the reestablishment of intercellular contacts and plasmodesma channels between different parents, thus forcing cytoplasm and chromatin to pass the cell wall with different qualities and quantities from one cell to others, through the enlarged intercellular plasmodesma channels or the vulnerable regions and the holes on the cell wall formed differently in growth and thickness in the process of cell wall formation to introduce external genetic substances or gene groups into plant cells. There are different ways, frequencies and strengths for the migration between the cells in different growth and development regions or the same growth and development region. In this paper we advance the mechanism of cytoplasm and chromatin migration through the cell wall: There are a large number of plasmodesma channels or vulnerable regions and holes different in growth and thickness during the formation of the cell walls between meristematic cells. Low osmotic pressure and low pH value K+ solution treatments force the augmentation of plasmic streaming, and the streaming of karyolymph, the relaxation of the cell wall, the formation of more holes on the cell wall and the enlargement of plasmodesma channels in meristematic cells. All these make a proper structural and physiological condition for migrating through cell walls. Osmotic pressure and centrifugal forces are the practical forces forcing cytoplasm and chromatin to migrate extensively and transfer external genetic substances or gene groups to plant cells.展开更多
基金The authors would like to thank PNRA(Italian National Program for Antarctic Research)for supporting sample collecting in the Antarctic,and the Italian National Antarctic Museum“Felice Ippolito”for supporting CCFEE(Culture Collection of Fungi From Extreme Environments)MIUR-PRIN 2008 is gratefully acknowledged for financial support concerning RIF studies in Italian Alps and ApenninesLaboratory work at the CBS was financed by the Royal Dutch Academy of Arts and Science(KNAW)and the Fonds voor Economische Stuctuurversterking(FES)with the grant‘Barcoding the CBS collections’.
文摘The last decade has revealed an unexpected fungal diversity associated with natural rocks,often collected in environments influenced by harsh climatic conditions.Yet the phylogenetic affiliations and the taxonomy of many of these extreme fungi,mainly within Dothideomycetes,the largest class of Ascomycota,have only partially been described.In the present study we confirm that most rock inhabiting-fungi(RIF)are highly polyphyletic among Dothideomycetidae,mainly within the order Capnodiales,an order otherwise incorporating several families of major plant pathological importance.Novel taxa were identified within the two major and distinct clades of Teratosphaeriaceae,both comprising meristematic black fungi.Thirty one novel species and 13 new genera are proposed,based on ITS and partial nucLSU,RPB2 and BT2 sequences.
文摘Microtubule arrays in prothalli large-vacuolated and meristematic dividing cells of the fern Dryopteris crassirhizoma Nakai were studied using Steedman's wax, indirect immunofluorescence labelling and confocal laser scanning microscopy. Results showed that the use of high paraformaldehyde concentration (8%) allowed good fixation of prothallus cells, which are characterized by numerous (meristematic cells) and big (large-vacuolated cells) vacuoles. Results also plead for the efficiency of Steedman's wax embedding method in: (1) avoiding excessive use of enzyme for digesting cell wall in the process of the microtubule cytoskeleton labelling, (2) minimizing the autofluorescence effect in cells through utilization of alcohol in sample dehydration, and (3) permitting a clear visualization of microtubule patterns during the cell mitosis. Steedman's wax, coupled with immunofluorescence labelling and confocal laser scanning microscopy techniques, allows a good investigation of cell division process in plants by using simple multicellular organisms such as fern prothalli.
文摘Callus and suspension cells culture of Kaempferia parviflora was successfully established. Meristematic shoots can be used for utilization of plant cell biosynthetic capabilities for obtaining useful products from valuable medicinal plant to meet out the pharmaceutical demand and also for studying the metabolism. The medium containing combination of 0.2 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.2 mg/L napthyleneacetic acid (NAA) promoted the highest callus induction at 20%. Transferring the initiated callus on the medium with 1 mg/L 2,4-D enhanced the proliferation rate up to maximum fresh weight of 6.71 gm. Growth curve of cultured cells revealed that the cells continued to grow until 50 days of culture and showed the highest peak (fresh weight) at 40 days in all different initial weight tested ( 0.2, 0.5 and 1.0 gram). Isolated embryogenic callus was found to produce the highest in weight when suspended in liquid medium supplemented with 1 mg/L 2,4-D at 110 rpm resulted 13.5 gram fresh weight and 1080 mg dry weight.
基金supported by the National Science Foundation Plant Genome Research Program postdoctorate fellowship,award 2410089 funded by the National Science Foundation,United States.
文摘Nitric oxide(NO)is a gasotransmitter-diffusible signaling molecule that is critical across organisms.In plants,NO plays an important function in growth and development,senescence,and the response to abiotic and biotic stress(Domingos et al.,2015).Our understanding of the mechanism for NO biosynthesis in plants is limited and centered around the nitrate reductase pathway.Two known NR-encoding genes in Arabidopsis thaliana,NIA1/2,are active in leaves and meristematic tissue(Olas and Wahl,2019),independently regulated in a tissue-dependent manner(Vidal et al.,2015),and required for NO synthesis(Chen et al.,2016).Non-coding RNA species,i.e.,antisense,long intergenic,and sequences processed into small microRNAs/small interfering RNAs(siRNAs)can be potent regulators of gene expression in plants(Traubenik et al.,2024).Previous work discovered two non-coding species originating from the NIA1/2 loci including a 22-nt siRNA(Wu et al.,2020)as well as an antisense RNA(asRNA)from the 3′UTR(Chekanova et al.,2007).The small siRNA derived from the NIA1/2 loci was found to restrain NIA1/2 translation,ultimately inhibiting plant growth and enhancing the stress response(Wu et al.,2020).How these long non-coding species specifically,as NIA1/2,regulate their respective protein-coding sense strands was not understood.In mammalian studies,a similar type of induced NO synthase(iNOS)protein has been shown to be regulated by its asRNA transcribed from the 3′UTR.
基金This work is supported by the National "863" Advanced Technique Development Project in China and the "7.5" Science and Technique Development Project in China
文摘A new cell engineering technique (L. B. technique) was established in our Lab. At first, the physical and chemical methods were used to facilitate the reestablishment of intercellular contacts and plasmodesma channels between different parents, thus forcing cytoplasm and chromatin to pass the cell wall with different qualities and quantities from one cell to others, through the enlarged intercellular plasmodesma channels or the vulnerable regions and the holes on the cell wall formed differently in growth and thickness in the process of cell wall formation to introduce external genetic substances or gene groups into plant cells. There are different ways, frequencies and strengths for the migration between the cells in different growth and development regions or the same growth and development region. In this paper we advance the mechanism of cytoplasm and chromatin migration through the cell wall: There are a large number of plasmodesma channels or vulnerable regions and holes different in growth and thickness during the formation of the cell walls between meristematic cells. Low osmotic pressure and low pH value K+ solution treatments force the augmentation of plasmic streaming, and the streaming of karyolymph, the relaxation of the cell wall, the formation of more holes on the cell wall and the enlargement of plasmodesma channels in meristematic cells. All these make a proper structural and physiological condition for migrating through cell walls. Osmotic pressure and centrifugal forces are the practical forces forcing cytoplasm and chromatin to migrate extensively and transfer external genetic substances or gene groups to plant cells.
