A research team led by Penn State biologists has uncovered a critical protein, GRP20, that plays a pivotal role in ensuring proper flower development across various plant species. The team’s findings, published in the journal Nature Plants, demonstrate that this protein aids in the accurate processing of RNAs, preventing the loss of essential components during the splicing process. The mechanism identified in the model plant species Arabidopsis is believed to be shared among different plants.
The researchers discovered that GRP20 is instrumental in processing RNAs for thousands of genes, contributing to the normal formation of floral organs, including petals and stamens. Furthermore, this protein is crucial for the plant’s ability to respond to its environment.
Hong Ma, the Huck Chair in Plant Reproductive Development and Evolution and professor of biology at Penn State, emphasized the significance of GRP20 in floral development. “The protein we identified in Arabidopsis, called GRP20, helps ensure that thousands of genes are properly spliced, and even the smallest exons are not missed in this splicing process for crucial floral regulatory RNAs,” said Ma.
RNA molecules, responsible for transferring information from DNA to produce proteins, undergo a splicing process to remove noncoding portions and connect coding parts. The spliceosome, a molecular machinery, and splicing-factor proteins regulate this process. The researchers found that GRP20 binds to RNA and interacts with the spliceosome, contributing to the proper splicing of genes involved in flower development.
Ma highlighted the importance of understanding the mechanisms controlling splicing, especially for genes with micro exons, which are short sequences often lacking specific recognition sequences. Disrupting the GRP20 gene led to improper splicing in over 2,000 genes during the plant’s development, particularly affecting micro exons in genes essential for floral organ formation and environmental responsiveness.
The study revealed that both RNA binding and interaction with the spliceosome are crucial for GRP20’s proper function in including micro exons in RNAs for normal flower formation. The researchers successfully rescued flower development by introducing proteins containing coded portions of micro exons or by introducing a version of the GRP20 gene from a closely related plant species.
The discovery of GRP20’s role as a regulator for RNA splicing opens avenues for further exploration into its functions in various molecular, developmental, and physiological plant processes. Given its conservation across plant species, researchers anticipate uncovering its role in other species, offering valuable insights into the intricate mechanisms governing flower development. The study was supported by the Penn State Eberly College of Science and the Penn State Huck Institutes of the Life Sciences.