The thale cress is to most of us a ubiquitous weed. But for scientists, it is akin to the fruit fly which has proved to be a wonderfully flexible tool for studying a whole range of biological processes. Now, it is in the news for the discovery of a new plant organ.
The Arabidopsis thaliana has also become recognized universally as a model plant for various studies. The plant has a relatively simple genome and a short lifecycle and is used by researchers to denote other plant life, and even animals and humans. It is also the first plant to have its complete genome sequenced.
But even the most studied plant of the world does tend to come up with a surprise now and then. A previously unnoticed plant organ was discovered by molecular biologist Tim Gookin, and his team. Gookin was previously with the Pennsylvania State University.
Scientists have closely studied the thale cress for over 4 centuries. But the unassuming weed has thrown up a fresh surprise. The newly discovered plant organ is akin to a cantilever beam used for supporting the base of bridges. It has been named the ‘cantil.’ The freshly discovered plant organ sticks out of the stem, ultimately connecting to the plant’s arm that bears to flowers, the pedicel.
The new plant organ of the thale cress, the cantil resembles bent elbows. If the plant organ is missing, they only have straight arms. The plant organ discovered neither is part of the pedicel or the stem. The new organ found in the thale cress is entirely new.
How Did Researchers Miss The New Plant Organ?
Gookin reasons that scientists may have missed the thale cress organ because it forms only when the plant interrupts its flowering. The cantils form in spring when the daylight is inadequate. During this season, the transition of the plant proceeds more gradually from the initial leaf-production stage to the final reproductive flowering phase. This happens much faster in the summer months with its strong sunshine.
This slow pace of the new plant organ, the cantil, gradually manifests just before flowering. That is just after the pedicel, with its flower tips, makes a debut. The plant organ never makes an appearance during the summer months with its long period of sunshine.
Researchers grow the plant under conditions that have longer daylight to accelerate the growth quickly to the phase of seed production. This doesn’t give enough time to the cantil, the hitherto unknown plant organ, to develop.
A second reason is that laboratories use the mutant strain of the thale cress for their experiments. This explains their unfamiliarity with the plant organ known as the cantil. This buttress structure doesn’t develop in this plant due to a gene mutation, says Gookin. Researchers doing their studies on these mutant varieties never get to see the unknown plant growth as it has been automatically canceled.
It took 12 years of painstaking research for Gookin to discover the new plant organ in the thale cress, the cantil. When back in 2008 he discovered the new plant organ, he suspected that they were created because of a mix-up in the various strains. But a number of years of experiments with natural and regular strains of the Arabidopsis finally convinced him that the new plant organ was a naturally arising phenomenon.
After further investigation on their causes, Gookin finally discovered that the cantil was not due to any role of the water, soil, air supply, or fertilizers. It was the flowering delay that caused the new plant organs to grow. It was a marathon task of inspecting 20,000 pedicels and raising by hand another 3,782 plants.
The cantils have not been discovered in other plants. Botanist Daisuke Urano though believes that structures similar to the cantil could be found in similar shrubs. Scientists believe that this study could help us develop strains that are more productive and stable by merely tweaking the plant architecture in various ways.