Speaker: Dr. Theodore Muth (Brooklyn College, City University of New York)
Title: Agrobacterium tumefaciens Attachment and T-DNA Integration – understanding the “root” to infection of host plants
Summary: While several aspects of A. tumefaciens infection and transformation of plants are well understood, there are questions that remain concerning the attachment of the bacteria to host plants and the integration of T- DNA into the host cell genome. Work from our lab has focused on these questions and has applied novel approaches in an attempt to gain a more thorough understanding of these steps in the infection.
The standard approach to genetically modify plants relies on
Agrobacterium tumefaciens to transfer foreign DNA (T-DNA) into plant cells
where it can become a permanent part of the plant cell’s genome and express
engineered traits. While A. tumefaciens transformation of plants has been used
extensively, there are aspects of the process that are incompletely understood.
To study the timing and factors influencing the location of T-DNA insertions,
we used a modified adapter ligation- mediated PCR strategy, coupled with next
generation sequencing, to identify T-DNA integration sites into the genome of
Previous reports examining T-DNA integration have relied on
selective conditions, floral dip transformation, artificial virulence induction
or use of cultured suspension plant cells. Our approach attempts to closely
match natural infection conditions by using cut Arabidopsis root segments
infected with uninduced A. tumefaciens and no selection for T- DNA integration
events. A more thorough understanding of T-DNA integration will guide future
experiments to develop the techniques to engineer plants more efficiently than
is currently possible.
<< Part 2>> 16:00 – 17:00
Speaker: Dr. Theodore Muth (Brooklyn College, City University of New York)
Title: The Urban Microbiome ? a new census of the city
Abstract: Our recent work using culture-independent (metagenomic) based strategies to study microbial communities shows an unexpectedly high level of biodiversity in urban microbiomes in a number of sites including parks, waterways, subway systems, and green infrastructure installations. The factors underlying the establishment of these diverse communities are not well understood, but it suggests that urban microbial communities represent a significant unknown element of phylogenetic, genetic, and functional biodiversity. A better understanding of these influences on multiple aspects of biodiversity will inform the design, construction, placement, and maintenance of urban environmental elements (such as green infrastructure) to maximize their ecosystem services. More fundamentally, our work offers a novel platform for exploration of basic science aspects of dimensions of biodiversity.
講演タイトル：Strategies and resource acquisition of ectomycorrhizal fungi and wood decay fungi in forest ecosystems
We will have a seminar by Dr. Erik Hobbie. He studies fungal functioning by using nitrogen dynamics. I hope many people come and join us. Polycom from branch office is available. I am glad if you inform me befor when you want to attend via Polycom (we will connect to HD1).
Date: 1 October 15:00～16:00
Place: Large conferece room (1st floor) in Field Science Center for Northern Biosphere (Experiment Farm)
Title: Strategies and resource acquisition of ectomycorrhizal fungi and wood decay fungi in forest ecosystems
We present two case studies of fungal functioning in forest ecosystems. In the first, we investigated functional differences in six taxa of decay fungi during a long-term log decomposition study (Oregon, USA) by studying elemental, isotopic, and compositional patterns in wood, cellulose, and sporocarps. Partitioning between protein and non-protein pools in mycelia prior to sporocarp formation controlled sporocarp δ15N relative to N sources. Radiocarbon measurements separated fungi into heartwood colonizers (Fomitopsis and Hericium, ~60-year-old carbon) and sapwood colonizers (Mycena (7 years), Hypholoma (11 years), and Trametes (11 years). Mycena and Hypholoma appeared to assimilate some 13C-enriched sucrose in sapwood rather than just cellulose. The six taxa varied widely in their chemical composition, as assessed by pyrolysis GC-MS; these compositional differences correlated with functional growth strategies. From these measurements, we improved the quantitative and conceptual understanding of functional differences of wood decay fungi. In the second study, we assessed how nitrogen (N) availability affected ectomycorrhizal functioning in two long-term (6-40 years) N addition experiments in Pinus sylvestris stands in Sweden. Sporocarp production declined dramatically with N fertilization but recovered slowly after fertilization stopped. Both sporocarp C/N and soil C/N increased with fertilization, implying that N uptake per unit fungal growth increased and then declined after fertilization had stopped. Fungal and soil d15N patterns across treatments identified fungal N sources, with N acquisition primarily from the S horizon for Paxillus involutus and Suillus variegatus, from the F horizon for four Cortinarius taxa and Lactarius rufus, and from the H horizon for Cortinarius traganus and Russula aeruginea. Taxa with proteolytic capabilities were particularly sensitive to N fertilization. These analyses illustrated that responses of fungal taxa across these fertilization gradients depended on the horizon of N acquisition and on N acquisition strategies.
Organized taking the opportunity that Claire de Mazancourt, I Fang Sun and Michel Loreau are in Sapporo. Everyone welcome!
Claire de Mazancourt
(French National Centre for Scientific Research, Paris)
“Invariability: measuring and understanding the effect of biodiversity on ecosystem stability”
Lunch break @Room A807
I Fang Sun
(National Dong Hwa University, Hualien; EES Hokkaido University)
“Plant reproductive decision-making and its consequence in a changing world: insights from a subtropical rain forest”
Osamu Kishida (FSC Hokkaido University)
“Growth of larval salamanders determines trophic interactions in a pond community”
Yoshio Masuda (EES Hokkaido University)
“A solution for Hutchinson’s paradox in simulated 3D oceanic
environments: coexistence of several dozens of similar phytoplankton
species at a point”
Shigeo Yachi (CER Kyoto University)
“How community-based ecosystem restoration can guarantee watershed-scale sustainability: origins and overcoming of scale mismatches in social-ecological dynamics”
Tea break @A807
Makoto Kobayashi (FSC Hokkaido University)
“Feeding behavior of detritivore determines the plant and soil response to climate warming”
Masahiro Nakamura (FSC Hokkaido University)
“Global warming effects on insect-plant interactions in tall trees of
Gaku Kudo (EES Hokkaido University)
“Expansion of dwarf bamboo in Japanese alpine ecosystems and its impact on biodiversity”
(Theoretical and Experimental Ecology Station CNRS, Moulis)
“Linking biodiversity, ecosystems, and people across scales: challenges for ecology and sustainability”
No registration required. We would appreciate your (while not students.) small donation for lunch and tea.
演者のFritz Schweingruber博士は、Swiss Federal Research Instituteの名誉教授で年輪年代学と植物解剖学の大家です。”Tree Rings – Basics and Applications of Dendrochronology”など多くの著書を出版しています。今回は北海道での調査のため来日されます。
日時： 5月30日（火） 15:30～17:00
場所： 地球環境科学研究院 A棟8階 A809室
講演タイトル： How old are herbaceous plants and how fast they grow? Introduction to ecological plant anatomy
演者： Fritz Schweingruber(1) and Jiri Dolezal(2)
(1) Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
(2) Institute of Botany, Academy of Sciences of the Czech Republic, and Institute of Low Temperature Science, Hokkaido University, Japan
Age structure, maximal longevity and growth rates are key attributes which scientists wish to know in most living organisms in order to understand their demography, ecological adaptations and responses to ongoing environmental changes. In the Plant Kingdom, surprisingly, these parameters are missing for most taxa. Most studies have focused on temperate woody plants while comprehensive data on extra-temperate species from e.g. cold alpine or warm tropical areas are rare. There is therefore an urgent need for a global-scale assessment of plant age and growth dynamics across ecosystems and evolutionary linkages. Recent advances in the anatomical assessment of distinct annual rings enables growth histories and age information to be precisely determined in the majority of dicot species, even in plants with a root collar thinner than 1 mm. The lecture will introduce “state of the art” in anatomical and age research in herbaceous plants, similarities with classical tree dendro-ecology and dendro-climatology, with examples from the High Arctic, Himalayas and Tropical Africa.
Fritz Schweingruber is a Professor Emeritus at the Swiss Federal Research Institute WSL, Birmensdorf in Switzerland. Published more than 160 scientific papers and 13 books on dendrochronology and anatomy of plants, currently working on monocots, alpine and aquatic plants.
Jiri Dolezal works at the Institute of Botany, Czech Academy of Sciences. Published more than 100 scientific papers on plant responses to climate and land-use changes. Graduated from Hokkaido University (supervised by Prof. Toshihiko Hara) where he is currently a visiting Associate Professor at the Institute of Low Temperature Science.