To find out how DELLA proteins changed over the 450 million years since plants first appeared on land, the researchers studied the mosses and liverworts, which are the plants likely to most closely resemble those early pioneering species.
Scientists already know that DELLA proteins in modern flowering plants are regulated by a plant hormone called gibberellin, which changes the levels of DELLAs in response to environmental conditions.
In the new studies they were able to show that, rather than having only simple interactions, the DELLA proteins’ range was just as complicated in early plants, but also different from the interactions studied in detail in modern crops such as wheat or rice. Moreover, these interactions were available whether or not the gibberellin hormone was present. They were also able to identify a core set of interactions, relating to defence and responses to low oxygen levels, that were common to all DELLA proteins.
Co-author, Dr Miguel Ángel Blázquez, of the IBMCP, said: “A very important area of work in gibberellin biotechnology is trying to obtain varieties or chemical compounds that allow us to achieve the desired goals without the side effects. Understanding how DELLA proteins have evolved in nature over millions of years helps us to design new strategies to generate new DELLA variants with the desired functions.”
The research was funded by the Biotechnology and Biosciences Research Council and Natural Environment Research Council, both part of UK Research and Innovation; DFG (German Research Foundation); MCIN (Spanish Ministry for Research and Innovation); and ERDF (European Regional Development Fund).
