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                                  International Plant appreciation day:  Food security

                                                            by @Jon Hale  








Looking at depictions of that asteroid impact, there is a common theme. Dinosaurs, frequently Tyrannosaurs, glancing over their shoulder at the asteroid signalling their doom. But what else do you see? Is it the pterosaurs, the tsunami, the plesiosaur or the leaves? Plants rarely get the attention they deserve. As humans we naturally give humans a lot of attention, then it’s other animals (just picture that wasp that’s got into the classroom) but then those visible organisms that are always in the background just get ignored, those plants and fungi that help maintain our planet.

Most people think of plants in one of two ways: aesthetically or nutritionally. Considering food, there are around 30 000 edible plants, but just 4 of them provide 60% of the world’s dietary energy intake - rice, wheat, maize and potato. Should we then be using these crop species when teaching photosynthesis, plant diseases and transpiration? Would this lead to a better connection between the science and food security? 

Each of these crop species has interesting contexts, for example, rice and Golden RiceTM can be used to introduce vitamin deficiencies, the universal genetic code, genetic engineering, ethics, etc, but what about using rice as a model for osmosis, or developing the application of osmosis to rice blast fungus which manipulates its water potential to punch a hole into the rice leaf cells. At A level, the discovery of gibberellins does continue the rice story, but auxins and abscisic acid also play a key role in how rice survives waterlogged soils when they are planted. Then there’s the role of flooding paddy fields, anaerobic decomposition of those competitors, the impact of monoculture, and climate change. There is a lot we could be tethering to an “off-the-shelf” plant.

Going back to the age of the dinosaurs, many students struggle to imagine what the flora would have been like 65 million years ago. I think this is another opportunity to shift a focus towards using more plant examples, in this case extinctions, natural selection and evolution. Just considering vascular plants, there has been an explosion in the number of different flowering plants in the last 100 million years or so, but how and why? Something that Darwin struggled with. Delving deeper into Earth’s history and it;s the time of the gynmosperms like conifers and cycads - the “naked seeds”. At their height, there were probably close to 40 different families of these (ca 300 million years ago). Now there are four.

Likewise a similar number of the fern families (pteridophytes) would have existed. What I find fascinating is that there are still examples of these types of plants clinging to existence. Whether it is a conifer in a park, a bracken in some scrub or a pavement plant-like red deadnettle, plants are showing resilience over incredible timescales. Is there the potential for students to compare the modern species to their ancestors with a Google image search, or develop the idea of genetic diversity driving evolution with scaling up of sexual reproduction in the age of the flowering plants?

However we do it, we do need to consciously decide to use plant examples more frequently in the classroom. SAPS have made a lot of excellent resources, including those that link plants to the other sciences and mathematics, like the physics of the coconut http://saps.org.uk/secondary/science-club-activities/840-maths-and-physics-of-coconuts-for-stem-science-clubs 

If you have any ideas, do drop a comment below and hopefully, we can inspire a generation of students that consider plants when they think of science.

Additional resource:

https://blog.education.nationalgeographic.org/2017/05/16/dinosaur-asteroid-hit-the-worst-possible-place/