PhD student Sandra Schmoekel is just back from growing glowing plants at Cambridge University. She worked in Prof Alex Webb’s laboratory to study the signals that plants use to respond to salt stress.
At Cambridge, Sandra grew Arabidopsis plants which had been transformed to produce Aequorin, a protein from luminescent jellyfish which glows blue when bound to calcium (Ca2+), a common signalling molecule in plants and animals. Sandra used the glowing protein to investigate how plants detect salt in their roots. She compared salt-sensitive and salt-tolerant Arabidopsis varieties to see if there was a difference in Ca2+ signalling between the plants.
Plants are very sensitive to their environment and their signalling pathways do a similar job to the nervous system of an animal. The signals initiate the plant’s response to environmental changes. When a plant detects a change in the environment (such as a build-up of salt in the soil) the levels of Ca2+ in the plant cell increase. The Ca2+ increase happens in the cell’s cytoplasm for a short time, and is specific to the environmental stress the plant is experiencing.
While we can see this Ca2+ signalling response moving through a plant, we do not know how the plant detects the salt (in this case sodium or Na+), in the first place. That’s why Sandra looked for a difference between the roots of salt-sensitive and salt-tolerant plants. Prof Webb’s laboratory is one of the top international research laboratories investigating signalling in plants, which made it a great place to investigate salt signalling.
Sandra’s research in Prof Webb’s laboratory proved fruitful in establishing an assay for measuring a plant’s response to salt. She plans to return to Cambridge in the near future to complete her research. Sandra’s experiments at Cambridge will contribute directly to her PhD thesis because they complement the research she is carrying out in Dr Stuart Roy’s laboratory at ACPFG. She also hopes the work will contribute to a future publication.
Sandra traveled to Cambridge on a Barr Smith Travel Scholarship from the University of Adelaide. In addition to her visit to Prof Webb’s laboratory, the scholarship allowed Sandra to present at the Gordon research Conference (GRC) on Salt and Water Stress in Plants in Hong Kong. The GRC is the top conference in the plant salinity tolerance field and gave Sandra the opportunity to present the results of her PhD to scientists from around the world.
“The Gordon Conference was a great experience,” said Sandra. “I was able to hear the latest science from experts in my field, and make contacts that will be valuable in my career.” While traveling, Sandra was also able to visit laboratories in China, the United Kingdom and Germany.
Salt stress is an important agricultural problem because it severely effects the growth of many important crop plants, resulting in significant reductions in yield. At present we know several of the salt tolerance mechanisms that can be used to make a plant more salt tolerant, but we do not know how a plant initially detects salt at its root. Sandra’s research will help reveal how this happens.