In the (flood-delayed) June issue of Annals of Botany we have review plant defences, with a twist. Professor Geerat J. Vermeij, Distinguished Professor of Earth and Planetary Sciences, at UC Davis looks at Plant defences both on land and in water, and asks why they’re so different. He’s been kind enough to answer a few questions from me.
You note that there’s been very little work done contrasting the defences of aquatic and terrestrial plants. Why do you think this is?
First, I think this is a symptom of specialization. People who work on land plants usually don’t think about plants (and especially algae) in water, and vice versa. Second, although there are thousands of papers on plant defense, the kinds of comparisons I find interesting haven’t been done. Most large-scale studies of plant physiognomy have emphasized climate and very broad categories of form, blade thickness and size. Frankly, most biologists think of their organisms in a quite abstract way without thinking of them as creatures that must make their way in a world full of biotic challenges.
A few things surprised me in the review. Plants not using colour as a warning is odd when, as you point out, many fish do exactly that. What do you think is the most surprising difference between plant and animal defences?
I am not sure this would be particularly surprising, but plants mostly do not use aggression in the way that many animals do. That said, the passive defences that plants employ are in principle not so different from those of sedentary animals.
Your career is much more than botany. How do you see these questions about plant defences connecting with your other work? Where can botanists make a valuable contribution marine ecology or palaeoecology?
I have a long-standing interest in plants, owing in part to my father’s training in arboriculture at Boskoop, the Netherlands. In all my work, I think deeply about the general patterns of evolution and the challenges organisms must face, and how these challenges have changed over geological time. By studying more than one major group of organisms, I get to see first-hand whether (and how) the evolutionary changes we see in one group are generalizable to others.
Paleoecologists have generally viewed plants from a paleoclimatic perspective (although there are some noteworthy exceptions); but they would profit greatly from a new viewpoint that emphasizes the ways in which plants have dealt with competition, herbivory, and the challenges of pollination and dispersal. There is a particularly wide chasm in understanding the role of ancient seaweeds in marine systems.
What advice would you give to someone starting out researching plant defences today? What advice would have helped you when you were starting your PhD? Is there anything that a blind student wanting to carve out a successful career in science, like you have, should know or prioritise?
My advice to those beginning studies of plant defence would be to realize that there is more to defence than chemistry. Physical-mechanical defences have been substantially ignored relative to chemical defences; and even less is really understood about how defence is reconciled with the necessity to attract animal dispersers and pollinators.
As for general advice, I tell my students to work on important questions that can in principle be answered. I believe strongly that a student must have passion for what he or she works on, and that the work must be oriented toward questions: what do you really want to know, and why is this potentially important? Can you explain your work in an engaging way to someone who is not a scientist or not a specialist in your area? Moreover, it would be best to emphasize one’s strengths.
For a blind person this would mean choosing questions and systems that are not excessively visual. When I started out, I had tons of passion and an abiding curiosity about shells, fossil and living, as well as about plants. My professors, without being explicit about it, were all strongly question-oriented, and were all engaged in research that to me seemed important (and has proven to be so in retrospect).
There’s a lot of concern about where the next generation of plant scientists are going to come from. What is it that brought you into plant sciences? What do you think botanists can do to improve their own biodiversity?
A love of nature helps, something I had from early childhood, much encouraged by my parents. In an urbanizing world this is increasingly problematic, even among scientists, most of whom think science is something done only in the lab at the molecular level. I would argue that professors should spend much more time emphasizing what we do not know than they do when teaching courses; and I think there should be far more engagement with actual specimens, like plants in the field or in greenhouses Most students have no appreciation of the fantastic diversity out there, and frankly don’t have the knowledge or background to ask questions. I also think it is really important to encourage close observation, a skill that educators have ignored at all levels of schooling.
If you read Dutch you might also be interested in Plantenleven op het land eist meer bescherming in Bioniuews.
You can pick up the review online now. Like all the reviews in Annals of Botany it’s available through free access, even if you don’t have access to a library with a subscription.
Geerat J. Vermeij, 2016, 'Plant defences on land and in water: why are they so different?', Annals of Botany, vol. 117, no. 7, pp. 1099-1109 http://dx.doi.org/10.1093/aob/mcw061