Space Cucumber Grown Aboard The International Space Station Reveals Unexplored Plant Secrets
(Photo : NASA Johnson/YouTube screenshot)
In an experiment that involved the study of the plant responses to gravity, preserved cucumber seeds were germinated in the International Space Station (ISS). The experiment was in continuation of a long-term study made that involved the study of the pattern of development of specialized protuberances, or pegs, during the germination of cucumber seeds.
These pegs are formed in early stages of seed germination. It helps the seedlings in emerging from their hard seed coat and also functions as an anchor for the developing seedling. The formation of pegs in an area regulated by gravity, which has intrigued scientists for years.
According to Hideyuki Takahashi, Tohoku University, Japan, the results obtained from the experiments done till now, seeds placed vertically in microgravity conditions, show that pegs develop on either side of the seed. On the contrary a horizontal positioning of the seeds suppresses the formation of peg on one side, i4U News reported.
Researchers loaded a few cucumber seeds into specially designed canisters and sent them to ISS for further experimentation. The water-absorbent plastic foam present in the canister was irrigated and the seedlings were grown in the cell biology experimentation facility of International Space Station for 24 hours, followed by their gravistimulation made by application of 1 gram of centrifugal force for 2 hours.
The cucumber seed samples grown in the ISS helped researchers in evaluating the role of gravity-sensitive CsPIN1 protein in the formation of pegs.
Microscopic Examination of the cross sections of the growing seedlings revealed that the CsPIN1 protein delocalizes under the influence of gravity, and change in the position of CsPIN1 protein at the transition zone of the cucumber seedling regulates the formation of pegs, according to NDTV.
The study results were published in the journal Nature Microgravity. According to the experts, transition of the protein stimulates formation of the cellular canal capable of delivering the growth hormones and possible turn on and off the process of development of the anchoring pegs.