In a recent study published in Nature Plants, Texas A&M AgriLife Research scientists explored the intricate processes plants use to produce microRNAs, which can help plants withstand drought, salinity, pathogens, and other stressors. By engineering artificial microRNAs, scientists can target specific genes for crop improvement. The team, led by Xiuren Zhang, found that less than half of the identified microRNAs in the model organism Arabidopsis thaliana were correctly classified, highlighting the need for further investigation and revised guidelines for designing artificial microRNAs to improve crops.
MicroRNAs are small molecules that play a significant role in gene expression regulation by guiding proteins to decrease gene expression. Changhao Li and Xingxing Yan were the co-first authors of the study, which reevaluated the landscape of microRNAs in Arabidopsis thaliana, providing a new understanding of microRNA biogenesis in plants. By using precise mutations and an innovative experimental design, the team identified genuine microRNA molecules in Arabidopsis and developed an effective methodology that can be applied to other crops and animals as well.
The study, funded by various organizations, sheds light on the complex process of microRNA production in plants. Arabidopsis thaliana, a model organism for plant biology, was used to demonstrate the diversity of microRNA precursors and the challenge of determining key processing features. Previous computational models based on chemistry failed to explain why diverse precursors yield products of the same size, prompting researchers to verify the microRNA precursors within plants to confirm their structural determinants.
By making highly specific mutations to the dicer protein, responsible for making precise cuts to microRNA precursors, the researchers were able to identify genuine microRNA precursors and reclassify others as a different type of RNA. Advanced techniques and computational methods were used to map out the structures of microRNA precursors in their natural cell conditions, revealing differences from computer predictions and literature. The team is excited to collaborate on investigating microRNA processing in agricultural crops for practical applications and to explore the potential of artificial microRNAs in other crops for crop improvement.
The findings from the study provide valuable resources and insights into microRNA processing in plants and offer a new understanding of microRNA structures and processing pathways. With additional validations of microRNA precursors in Arabidopsis thaliana underway, the team aims to explore microRNA processing in other crops and develop strategies for designing artificial microRNAs. This study opens the door for revisiting other crops, identifying areas for improvement, and expanding the use of this tool in crop improvement efforts.