Scientists at the RIKEN Center for Sustainable Resource Science reported
their discovery of a hormone-like small protein that helps plants increase
their tolerance to excessive salt. The report is published in the
Proceedings of the National Academy of Sciences of the USA (PNAS).
They started the study by looking for small proteins linked to salinity
tolerance through microarray analysis. Each of the genes that were expressed
more under high salinity conditions was overexpressed in transgenic plants
and then the transgenic plants were exposed to salinity stress test. Four of
the transgenic plants showed better tolerance to salinity compared to the
control plants. Then they focused their investigation on AT13, which induced
the greatest tolerance to saline conditions.
Further tests showed that levels of the AT13 peptide naturally increased
when plants were exposed to salt stress. Thus, the team searched the most
important part of the peptide by making pieces of the AtPep3 peptide
synthetically. They later found that treating plants with one section of the
peptide (AT13-5) was as effective as boosting tolerance through transgenic
overexpression of the gene.
"Peptides are natural compounds that are safer than genetically modified
plants," said Kentaro Nakaminami, lead researcher of the study.
"Additionally, potential supplements made from synthetic peptide fragments
will be easy to apply to different species of plants," he added.