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私は坂本亘教授との共同研究のため、毎年、岡山大学資源生物科学研究所にお邪魔していますが、それも今年で十年目となりました。そのために研究所の先生や学生に数多くの知り合いができ、一年ぶりに会うと“また来ましたね”と挨拶されます。しかし、今年はいつもと少し違い、７月１日から１０月３１日までという４ヶ月の長い期間を外国人特別研究員（客員教授）の身分で滞在することになりました。日々の経つのが早く、あっという間に４ヶ月間が過ぎてしまいました。この４ヶ月間を振りかえって見ますと、私は研究所における研究の進展や最近の改組の成果を学び、数多くの先生と科学研究及び研究費のあり方、それに具体的な研究内容や方法についても議論することができました。これらのことを通じて、私は資生研に新たな活気を感じ、自分の今後の大きな励ましにもなりました。長くて短い４ヶ月間でしたが、私にとって大変有意義な時間でした。
　まず、今回の研究所訪問で初めて知ったのが“ジャーナルクラブ”という勉強会でした。若い研究者を中心としたグループが新しい或いは面白い論文を積極的に読んで白熱的に議論することは皆さんの研究への熱意を反映しているように思います。また、皆さんと話をすると、各自の業績（論文）や研究費の申請への真剣さも以前になかった強いものになっています。このような動向は、近年、資生研で進められてきた「改革」によるものだろうと思いました。従来この研究所で多くの先生方々が築き上げた特徴のある素晴らしい研究に加え、最近持たらされた若手の活気が、いっそう資生研を日本及び世界で競争力のある研究機関に持ち上げるだろうと感じました。中国の主な大学でも、最近、競争を研究に導入しています。そのやり方は日本と似たようなところもありますので、今後、資生研の経験を参考にしたいと思います。
　以前から資生研へ来るたびに、私はここの図書館を利用しました。中国で見つからなかった学術誌や忙しくて読み損ねた論文をここの図書館からコピーし、または図書館を通じて取り寄せて読みます。中国では図書館と図書館の間のネットワークがまだ確立されていません。このため、大学の図書館にない学術誌を読む場合、自ら科学院あるいは市の図書館へ足を運ばなければなりません。行き来に時間がかかりますので、ついに多くの重要な論文を読み損ねることになります。私はこの問題を資生研の図書館では解決することができました。近年、岡山大学の電子ジャーナルは大変に豊富になり、また日本全国からの論文（ハードコピー）の取り寄せも早くて便利なので、私は今回も沢山の論文をダンロードしたり取り寄せてもらったりして読みました。本国の大学を離れれば、日常の雑用からも解放されますので、ゆっくりと考えながら読むことが出来ました。研究者に時々ゆっくりと論文を読むことは大事な“充電”だと思っています。今回の４ヶ月間の充電により私はいくつか重要な研究案に思いつき、国に帰ったらさっそく実験を始めようと思います。
　交流と充電のほかに、私は今回、資生研で具体的な研究活動に加わることも出来ました。シロイヌナズナの花粉に関する突然変異体の解析は、これまで坂本亘教授と行っている共同研究の一つですが、今回は松島良助手も一緒に、この解析を引き続き進めました。実験に用いた材料は花粉の栄養細胞にオルガネラDNAが沢山残る変異体で、私が協力したのはDNAを残すオルガネラの同定などです。簡単そうに思われる実験ですが、胞子に当たる花粉の電顕観察は従来から難しいものだと知られ、今回も苦戦しました。幸いに多くの手法を試した結果、最後に納得の行く電顕像が得られ、DNAを残すオルガネラはミトコンドリアではなく、プラスチドであることが分かりました。このことは遺伝子の機能を理解するために重要な結果で、続く解析に役立つでしょう。また、今回私達が見いだした花粉の観察法により、非常に鮮明にオルガネラを観察することがわかったので、新たな手法として確立したいと思います。
　資生研で坂本さんと実験をしているとき、以前から感心して学んだことの一つとして共通機器の管理と使用とがあります。高価で重要な設備を共同で購入して使用することは効率的だと中国でも思われています。しかし、中国の大学では共通で使用することより研究室による管理が強調され、誰でも２４時間使える態勢とせず、ついに管理する研究室のものになってしまうケースがほとんどです。私は２年前に電子顕微鏡の管理を任され、このとき、資生研のやり方を導入しました。その結果、今では電顕室が開放され、誰もがいつでも気軽に利用できるものになっています。資生研では共通機器の使用に問題がなく、とても素晴らしいと思います。この上にメンテナンスの費用や機器の場所などをさらに合理化して確保すれば、共通機器がよりよい効率で皆さんの研究に役立つでしょう。
　私は今回、おもに電子顕微鏡を使った実験を坂本さん、松島さんとしました。２年前と比べれば電顕室とその暗室がかなり狭くなっています。原因の一つは資生研に電顕の使用者が少ないからでしょう。記録を見ても、使ったのは私ともう一人の先生ぐらいで、ほとんど機械が稼動していないことも事実です。確かに世界的に電顕に頼って仕事をする研究者が一時減りました。しかし、ここ数年、分子生物学の研究においても細胞構造の変化を確かめたデータが求められる傾向になりつつあります。北京大学でも、一時、年間十数時間しか稼動しない電顕が今、使用者が順番待ちをする状態となっています。今回資生研に来る直前に、蛋白質の高次構造を解析している教授から電顕の使用申請があり、予想外だったのでとても驚きました。でも、蛋白質の高次構造も電顕で観察できるのは事実です。今後よりよい結果を出すために、多くの研究分野において電顕が不可欠になるでしょう。利用者の一人として、資生研でも、電顕室をより大事にし、出来れば顕微鏡の更新が近い将来あればと願っています。
　今回資生研で場所が狭くなったと感じたのは電顕室だけではありません。複数の先生から場所が足りないと聞きました。私が実験をしている坂本さんの実験室も面積的にぎりぎりで、松島さんと学生さんの部屋も実験室と一緒で、生物学の実験を行うために必要なドラフトは付けられていません。このため、私は庭に降りて危険物を使う操作をすることもありました。私の勝手な考えですが、これまでの私の観察では、研究所の総面積は決して小さくなく、また、十年前と比べて教官の人数はほとんど変わっていませんので、面積が足りないことには恐らく使用の合理化に余地があるのではないかと思います。北京大学では実験室面積を有料使用とした結果、かなりスペースが空くようになりました。また、徴収された使用料は共通の機器管理などに活用しています。客員教授の身分で、色々提案することは余計なのかもしれませんが、北京大学の経験が資生研に参考になれればと思います。
　以上のように振り替えって見ますと、私は資生研で勉強、交流、充電、実験と大変充実した４ヶ月間を過ごすことができました。今回、客員教授としてこの貴重な機会与えていただいた資生研、そして岡山大学に感謝を申し上げます。また、大変お世話になった先生と学生の方々にお礼を申し上げながら、私の報告とさせていただきます。

2005年10月31日

(北京大学生命科学学院　教授)

(in Japanese)

I am very grateful and honored to have received the invitation from Director Takeda and Drs. Murata and Nagaki to spend five months as a visiting researcher at the Research Institute for Bioresources. The RIB has been welcoming and generous in its support, and provided opportunities not only to work with my host lab and interact with other labs at the Institute, but has also aided in hosting the RNAi conference and in supporting my travels to other labs in Japan. This has been a very valuable experience for me, and I hope that I have been able to contribute a small amount in return.

　The project I selected, investigating the conservation of a centromeric histone protein in dinoflagellates, which have been thought to lack histones, has unfortunately proven to be quite intractable because of technical issues. Dr. Murata and Dr. Nagaki have nevertheless generously provided technical suggestions and laboratory resources to aid me. I also received help from Dr. Sakamoto’s lab, and as a result of travel supported by the RIB, from Dr. Andreas Houben, a visiting professor at the University of Kyoto, and from Dr. Kato Koichi at Nagoya City University. As of this writing, Dr. Kato is still trying to help me resolve the technical problems with this project.

　Although my project has not been very fruitful, my visit with Dr. Houben, who is collaborating with Drs. Murata and Nagaki on investigating holocentric chromosomes in Luzula, has led to my being able to contribute a small amount to this collaboration, namely providing an evolutionary analysis of centromeric histones in Luzula species. I have also reviewed manuscripts and participated in discussions of lab research reports and journal clubs. In retrospect, I regret that I did not participate more regularly in journal clubs from the beginning of my stay because I over-estimated the language difficulties. Since the papers are generally in English, I might have been able to contribute more here than I did.

　The RIB is a well-equipped and diverse place. At the beginning of my stay, I wondered numerous times whether the chemicals or equipment necessary for certain experiments were available, and each time I found that they were. I am also impressed by the diversity of topics being studied here, and was pleased to find a breadth of on-line journal subscriptions available. The expertise of researchers here is quite good, as evidenced by the numerous awards they have received.

　It is my general impression that Japanese students are on the whole a bit more shy or quiet than their American counterparts. Because discussion and questioning of data are critical to scientific development, I believe that it is important to encourage students to actively participate in discussions. Since I am not aware of all aspects of student training here, I’m uncertain as to what additional encouragements could be tried, but perhaps occasional student-led poster sessions or discussion groups might encourage greater interaction.

　I am particularly grateful for all the extra work undertaken by Drs. Murata and Nagaki to translate for me and my family. When we struggled with understanding my daughter’s first grade homework, Dr. Nagaki would help to translate, and when we needed a doctor, Dr. Murata accompanied us. Their assistance in these and many other situations made our time here relatively trouble-free.

　The use of the apartment on campus was also very helpful to my family. The apartment is generously sized for a family of three, and the karin in the backyard made excellent jam. It is conveniently located for work, and also for my daughter’s school, Kurashiki Nishi Sho Gakko, where we were extremely fortunate to get a teacher who spoke English and who worked hard to help my daughter feel fully included.

　In addition, the very inexpensive rent for the apartment enabled my family to do a fair amount of traveling in Japan that greatly enriched our experience of Japanese culture. We were able to make several trips to Kyoto, Nara, Himeji, Marugame, Hiroshima, Osaka, and Tokyo, in addition to enjoying the rich offerings of Kurashiki and Okayama. We particularly enjoyed bicycling in Kibi-ji, visiting Miyajima with Dr. Murata, and feeding saru at Arashiyama. We also took advantage of Okayama-ken’s International Villa program for foreign visitors, which enabled us to go bird-watching in Ushimado and hiking on Shiraishi Jima.

　The spirit of international exchange on both cultural and scientific levels has been an invaluable experience. I am deeply grateful to Drs. Murata and Nagaki, my co-workers in their lab, Director Takeda and the staff of the RIB, Okayama University, the teachers of Kurashiki Nishi Sho Gakko, our neighbors, and many other people in Japan for their kind assistance throughout our visit. I look forward to maintaining contact with my Japanese colleagues and hope to be able to visit again in the future.

(Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center)

The experience I had as a visiting professor at the Institute for Bioresources, Okayama University, Kurashiki was highly rewarding on both a professional and personal basis. Professionally, I had the opportunity to work with the leading authority on silicon in plants, Dr. Jian Feng Ma. In fact, I also learned that Dr. Ma is a leading expert in understanding both physiologically and molecularly how plants tolerate Al, Fe and Cd. He has surrounded himself with a great group of hardworking and determined graduate students and postdocs, all whom are helping to further elucidate the above. It was a great pleasure to have the opportunity to learn from them about their individual research projects and to observe their genuine curiosity about the research they were conducting. I also enjoyed seeing how Dr. Ma creates a warm working environment that makes his students and postdoc’s feel like a family.
As I mentioned, Dr. Ma’s lab is leading the world in understanding how silicon functions in plants. His group was the first to demonstrate and characterize silicon transporter genes in rice. His group is currently studying other plant species to determine if silicon transporter genes are present. In addition, Ma’s group knows how to quantify both the insoluble and soluble silicon content of plants. By using his silicon research approaches, Dr. Ma and I were able to better resolve the potential mechanism of how this element is affecting plant disease development. In particular, we used a silicon nutrient culture method to test the hypothesis of whether silicon confers resistance to plant disease (rice/Magnaporthe oryzae pathosystem) via a mechanical barrier (polyermization of Si in plant tissue-insoluble silicon) or through soluble silicon amplifying a plant mediated defense response via the production of enzymes or phytolexins. Preliminary results suggest that perhaps both the insoluble and soluble silicon confer rice blast resistance. We still have some more data to collect such as insoluble and soluble silicon in the leaf tissue and the number of silica bodies formed. In addition, RNA will be extracted from tissue collected 24 and 72 hours after inoculation and will be subjected to microarray analysis using the new rice gene chip. Hopefully, this information might reveal which genes are up or down regulated by silicon during the infection process. Based on all the above, I believe that Dr. Ma and I will have some great information to report in the not too distant future.
While working with Dr. Ma, I also had the opportunity to meet and learn about other outstanding research programs at the institute that included the plant-microbe interaction group, entomology, soil science and remediation, and plant breeding especially with barley. All these programs have state of the art equipment for conducting research. Needless-to-say, all of these units are conducting cutting-edge research, and training many students not only from Japan but from other countries such as China, Greece, Paraguay, Tunsia and Turkey. Interestingly, the institute also focused on presenting their research findings to the general public by having an open house which they do annually. So, this institute does a terrific job of communicating not only to the scientific community but to the community at large.
Personally, I was able to have better than a bird’s eye view on the Japanese culture. The food, customs, language and scenery were all remarkable and fascinating. I enjoyed the wide variety of delicious fish and vegetable dishes, and the exquisite style of food presentation was titillating to the eyes. I truly delighted in the custom of having hot towels provided to clean one’s face and hands before each meal; we need to adopt this method back in the US. The language was fun to learn, and I enjoyed the few phrases that I mastered. In fact, I became so good at greeting people, that one night at one of the yakitori, where I sort of know the owners, I greeted the owner and our exchange went so well that one of her other customers began to talk to me since he thought I could speak Japanese fluently. The landscape also was so picturesque from the rice fields surrounding the farmers’ homes to the rolling hills and mountains to the Shinto Shrines and Buddhist’s Temples, truly a land of the rising sun.

(UFRF Professor of Plant Pathology, Institute of Food and Agricultural Sciences, Department of Plant Pathology, University of Florida)

It was a great honour for me to be invited as a visiting professor at the Research Institute for Bioresources, Okayama University. Although I spent only a brief period (two months) here at Kurashiki, I thoroughly enjoyed the experience both professionally and personally. Before I came to the Institute, I already had some collaboration with Professor Jian Feng Ma on the research of metal uptake and detoxification in hyperaccumulator plants, with four joint publications over the last two years. This visit served to further strengthen the on-going collaboration. I had numerous discussions with Professor Ma, and benefited greatly from his experience and knowledge, particularly from the molecular physiology aspect. Overall, I am much impressed by the cutting edge research of Professor Ma’s group. They have a great strength in combining the approaches of plant physiology, biochemistry, molecular biology and genetics in plant nutrition and stress research. I am also very impressed by the enthusiasm and hard-working attitude of the postdocs and PhD students in Professor Ma’s group. I participated and enjoyed their regular group meetings, and learnt a great deal from them. The research facilities were also excellent.
Professor Ma is an internationally leading scientist in the research areas of Si and Fe nutrition, and Al tolerance mechanisms in higher plants. While at the Research Institute of Bioresources, I had the opportunity to conduct some experiments to characterise the rice naat1 mutant that has a point mutation in the naat gene. The gene encodes nicotianamine aminotransferase, which is a crucial enzyme in the biosynthesis of phytosiderophores that are important for Fe acquisition in graminaceous plants. The naat1 mutant showed severe symptoms of Fe deficiency when grown in soil under dry land conditions, but was able to grow normally under submerged conditions. This suggests that the mutant was able to take up Fe(II) under reduced conditions, but could not acquire Fe(III) from aerobic soils efficiently. Using the facilities of Professor Ma’s laboratory, we demonstrated that the mutant could not secret any phytosiderophores, unlike the wide type rice that secreted a large amount of 2’-deoxymugineic acid in response to Fe deficiency. This explains the phenotype exhibited by the naat1 mutant grown in an aerobic soil. Surprisingly, the mutation of the naat1 gene led to upregulation of a range of metal transporter genes, which probably explains why the mutant took up significantly more Zn and Cd than the wide type in our experiments. The experiments that I conducted at the Research Institute of Bioresources form a part of a larger project led by Professor Wu Ping of Zhejiang University, China. I am confident that we will be able to produce a good paper together from this project.
During my short stay in Japan, I had the opportunity to attend the annual conference of the Japanese Society of Soil Science and Plant Nutrition in Akita, where I met some old friends and made new friends, and the international workshop on biomonitoring and environmental protection organised by the Research Institute for Bioresources. I enjoyed informal discussions and exchange of ideas with Japanese colleagues in these meetings.
My brief stay in Japan enabled me to have a deeper understanding of the Japanese culture and the way of life. Public transport in Japan is so much better than that in the UK. Everywhere in Japan that I visited, service was always fantastic. I greatly appreciated the friendly atmosphere and peaceful environment in the research institute and the local city Kurashiki, as well as in several cities that I visited. All in all, this visit was a very memorable experience for me.

(Principal Research Scientist, Agriculture and Environment Division, Rothamsted Research)