Are plant petal cells round? (BioE80 Spr2015)

From the first lessons in plant biology, we are taught about the rigid cell walls that differentiate plant cells from animal cells: plant cells are visually described as having rectangular shapes, generally for support and structure. However, I wanted to use the Foldoscope to observe and see if flower petals exhibited the same phenotype as your “typical” plant cells (think stems and leaves). Flower petals are, generally, more visibly soft, easily bent, and aesthetically pleasing on a macroscopic level. As a result, we decided to dive in and go down to a smaller level to see what was up.

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Here, we can see a purple flower petal viewed using the Foldoscope, and the result is simple yet elegant. Not only are they not rectangular, the cells are all circular and clumped together. It is hypothesized that this shape for flower petal plant cells are optimized for pigment absorption in that they focus light more easily for absorption. Another hypothesis for this trait may also be tied to pure aesthetics: the circular shape allows for a more fine-tuned texture that is more desirable for pollinators.

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To conclude, I am curious about the following: how does cell shape change when we introduce multiple types of flower petals? Although our sample size had great photos for observation, it was limited to one type of flower found in the Engineering Quad. How do these different evolutionary stigma contribute to cell shape development and how may this compare for different types of plants? If we were to collect a wide variety of sizes, colors, etc. of flowers across campus, would their cell shapes be different, or all optimized the same way?

Contributor: Shankara Anand


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