Dechang Cao: The Seeds of Fascination

Botany One interviews Dr Dechang Cao for Fascination for Plants Day and learn more about his life mission to understand the mysteries of seed germination.

With Fascination of Plants Day approaching, Botany One has prepared a series of interviews with researchers from around the world working in different areas of botany to share the stories and inspiration behind their careers.

Today, we have Dr Dechang Cao, the Principal Investigator of the Seed Molecular Ecology Group of the Kunming Institute of Botany of the Chinese Academy of Science. Cao’s group is interested in the different aspects of seed germination and dormancy, particularly in seed responses to smoke. He is also an Assistant Features Editor in Plant Physiology –one of the leading Plant Science journals.

Cao at his office in the Kunming Institute of Botany (China). Photo by Dechang Cao.

What made you become interested in plants?

    Seeds. Many people are astonished by seeds because the small piece can explode into a giant tree. I am fascinated by the wisdom of seeds to survive harsh environments. They know how to avoid germination when the environment is not favourable for plant growth. When plants appear in the form of flowers and trees, it is a flourishing world. When they appear as seeds, the world is quiescent and waiting for the next flourish. Seeds teach me that there are both sweet and harsh sides to life. We have a Chinese saying that da ze jian ji tian xia, qiong ze du shan qi shen (达则兼济天下,穷则独善其身). It means that we should help people and the world flourish when being powerful, and we should strengthen ourselves when in obscurity. This is also the philosophy of plants. Thus, I love seeds, I love plants.

    What motivated you to pursue your current area of research?

    I feel that it is like walking on a pathway and suddenly realizing I am in this field. When I was a bachelor’s student, I read a book about plant ecology. It says that plant ecology is a kind of special knowledge about the philosophy of plants (to cope with the world). I felt that it was really cool to learn it. Thus, I participated in and passed the examination and started my graduate study in the major of plant ecology. During this period, I studied the seed rain of a poplar tree (Populus euphratica) in a desert. Then, I learned more about seeds, and I kept working on seeds. When answering your question, I realized it is my 17th year since I was connected to seeds, and I feel I love seeds more and more.

    What is your favourite part of your work related to plants?

    Seed dormancy. As I said before, seeds know how to avoid germination under unfavourable conditions –that’s seed dormancy! Seed dormancy is an innate characteristic of seeds that delays germination. There are different ways to delay germination by the seeds. For example, they might possess hard, impermeable coats that prevent water from coming in. They may also pause embryo development, such that the mature seeds need to wait for the embryo to fully develop until they can start germination. Even more fascinating, some seeds have physiological dormancy, where the seed coat is water permeable, and the embryo is fully developed, but the seed is still reluctant to germinate. In such cases, there are physiological obstructions that prevent seed germination. It remains elusive how seeds obtain dormancy and how dormancy is released. However, we cannot skirt around these questions because we need to manage seeds in our lives. It is a challenging and exciting work to explore the ways to seed dormancy.

    Cao in the field after a prescribed fire. Photo by Dechang Cao.

    Are any specific plants or species that have intrigued or inspired your research? If so, what are they and why?

    Yes, the coyote tobacco (Nicotiana attenuata). This plant made my work different. When I did my postdoctoral research at the Max-Planck Institute for Chemistry (Germany), I first got to this plant. I used it to study smoke-promoted seed germination. Some plants regenerate after forest fires, they are known as “fire-chasers”. Coyote tobacco is a fire-chaser. In their native habitat in the Great Basin Desert in North America, they germinate and regenerate in the first 3–4 years following fires. Then, they are taken over by other plants. The seeds of coyote tobacco stay in the soil and wait for the next fire to wake them up. It is amazing that the seeds need smoke produced by forest fire to help commence germination. I tried to study the active chemical compounds in smoke that promote seed germination using this plant. With the help of my teammates, I finally identified a compound in smoke that cues seed germination of coyote tobacco. It is syringaldehyde. This is a product of lignin combustion. Before our report, it was regarded by many people that karrikins, pyrolytic products of cellulose, were the major smoke cues for seed germination. Our findings opened a new window for us to navigate smoke-promoted seed germination. It is not always easy for new findings to “combat” old knowledge. The most important thing about this project is that I learned to communicate with the community to help the new knowledge “grow”. I believe that my work will be totally changed by this experience.

    Nicotiana attenuata the plant that Cao has used for his research. Photo by Jim Morefield, Wikicommons.

    Could you share an experience or anecdote from your work that has marked your career and reaffirmed your fascination with plants?

    Carol C. Baskin and Jerry M. Baskin, the famous seed scientists at the University of Kentucky, are the most important to affirm my career. On the first days when I started my PhD study at the Institute of Botany, Chinese Academy of Sciences, my supervisor, Prof. Zhenying Huang, told me that I should go to meet the greatest scientists, Carol and Jerry. At that time, Carol and Jerry were visiting us. I was a little nervous but very excited when I went to them in the Xiangshan Hotel near our institute. Surprisingly, they were so nice to talk about the theories about seed dormancy with me. Even though I was not good at speaking English at that time, they were patient in talking about details of seed burial experiments to help me develop my experimental design. I was impressed by their friendship and elegance. In the following years, I read their book and knew that their fascination with seeds was ignited by Prof. Elsie Quaterman, who taught them a seed germination course at Vanderbilt University. I must admit that the seed of my fascination with seeds was sown by Carol and Jerry. I feel that the seed is germinating, and I am looking forward to sowing the next-generation seeds.

    What advice would you give young scientists considering a career in plant biology?

    I would prefer “enthusiasm” to “career”. When you love it, you feel happy to do it, even if you are facing a lot of difficulties. Thus, fascination should be the prerequisite for you to start a career in plant biology. When you start it, I would suggest:

    1. Get prepared for difficulties and failures.
    2. Find a most interesting field of study.
    3. Keep critical thinking. 
    4. Try to communicate with your friends and the community about your research.

    What do people usually get wrong about plants?

    Previously, I felt that people usually got wrong about seed dormancy because even some scientists cannot distinguish the release of seed dormancy and the process of seed germination. Recently, I found that misunderstanding about plants is much more common than we expected! Some people ask me whether we can select some post-fire plants that can be grown in hotter environments. I was so confused why they asked such a question. Then, I realized that they thought that the seeds of post-fire plants could survive the high temperature of fire. The fact is that the temperature decreases in the deeper soil in the fire. Seeds in the deeper soil can survive fire and commence germination after fire. Sometimes, the misunderstanding may be harmful. Some government officials believe that fire totally kills the forest. They remove all plants in the burns and conduct planting projects to “help” forest recovery. They do not know that post-fire plants can regenerate on many occasions. It is a pity that we still have so many misunderstandings about plants in such a “time of science”.

    Carlos A. Ordóñez-Parra

    Carlos (he/him) is a Colombian seed ecologist currently doing his PhD at Universidade Federal de Minas Gerais (Belo Horizonte, Brazil) and working as a Science Editor at Botany One and a Social Media Editor at Seed Science Research. You can follow him on X and BlueSky at @caordonezparra.

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