Plants come in all shapes and sizes, and even the mighty oak tree can be convinced to grow no larger than a house cat. Our expert Robert Sablowski reveals whether there’s a towering giant waiting to burst out of your bonsai.
It’s a question many of us may have asked while marvelling at a well-pruned bonsai. If this is a miniature version of a large tree, would planting it in the ground unleash its true potential? The answer is yes, probably.
“Plant development is famous for being very flexible, and very dependent on the environment,” says Sablowski, head of the Cell and Developmental Biology Department at the John Innes Centre. “The reason why a bonsai tree is small is because it is under constant pressure, and constant constraint,” he adds.
The physical expression of most living organisms – the phenotype – results from a combination of genetic instructions and the surrounding environment. Humans grow from a genetic plan executed while we’re in the embryo, with comparatively little development after birth. Plants, on the other hand, continuously form new organs including leaves, roots and flowers, which originate throughout the plant’s lifetime from structures known as meristems. This constant regrowth from source is what makes them so flexible.
“Every moment is a new opportunity to respond to a change in the environment,” Sablowski explains. Meristem cells in bonsai trees are the same as in their larger counterparts, with similar genetic instructions. “Given access to enough nutrients, light and water, they’ll try to do what they’re genetically programmed to do, which is to produce a normal tree.”
Through the EU-funded SOS-CROPS project, Sablowski investigated some of the genetic underpinnings that control plant growth. Shorter crop plants produce greater yields in agriculture, as taller versions are more vulnerable to the elements like wind and rain.
Agronomists have therefore bred smaller versions, but this can result in unwanted side effects. Sablowski’s team tried to over-activate a gene controlling stem growth as an alternative way to produce a shorter plant. The work shed light on how plants control their size.
If you’re thinking of turning your bonsai big, Sablowski cautions that while the plant should reach its full potential, there could be one small architectural hiccup: “You may see the remnants of a tiny bonsai trunk at the bottom of the tree.”
Best to plant it out of the wind.
Click here to find out more about Robert Sablowski’s research: Are plant height and shape genetic?