Research

We collaborate with Jeff Caplan at the University of Delaware to develop and apply novel methods for RNA localization. Via this long-running collaboration, we’re utilizing super resolution and single-molecule approaches to quantify and localize RNAs of interest. The primary objective is to determine where and when different small RNAs and mRNAs are localized and accumulating. Most often, we’re focused on anther biology, as represented in these images, which display one lobe or a section of a lobe of a maize anther in cross-section, probed with RNAs involved in anther development. We are asking questions like: Where are these RNAs made? Where do they function? How are 24-nt secondary siRNAs made? And how do these processes vary across diverse plant species?

In the Meyers lab, we develop and use a wide variety of bioinformatics tools and pipelines, mainly focused on genomic analyses of plant small RNAs. We have a customized genome browser that is optimized for the display, analysis, and query of small RNA, and mRNA data. We have developed apps for the analysis of small RNA targets, cleavage, genomic distributions, and variation across different genotypes. These tools help promote public access to our data and algorithms. Via collaboration with Hagit Shatkay at the University of Delaware, we have developed machine learning approaches to characterize different classes of plant small RNAs. We are asking questions like: What features distinguish different types of small RNAs? Which mRNAs or other types of RNAs are targets of reproductive small RNAs? Which small RNAs or classes of small RNAs are impacted in different mutants?

Much of our current work focuses on phased, secondary siRNAs in anther development, mainly in collaboration with the lab of Virginia Walbot at Stanford University. There are two classes that accumulate to significant levels during grass anther development – premeiotic 21-nt phasiRNAs, and coincident with meiosis, 24-nt phasiRNAs. Together with former post-doc Rui Xia (now at South China Agricultural University), we have shown that the 24-nt class likely emerged coincident with flowering plants. When either class is perturbed, male sterility can result. Our major questions of interest include: What is the molecular basis of environmental sensitivity in grasses with disrupted reproductive phasiRNAs? What do the 24-mers do in tapetal development? What’s the role of the 21-nt reproductive phasiRNAs, and when & how did they evolve? And are there potential applications of these pathways for hybrid production in diverse grasses?

The self-fertilization limits the production of hybrid seeds in species of the Tritceae tribe. The control of pollen production can underpin the production of hybrid seeds in many crops and generates hybrid vigour known as a major factor contributing to high yield. To control pollen production, in wheat and barley, we are investigating the role of reproductive phasiRNAs as a candidate molecular mechanism to achieve  photoperiod/temperature conditional genic male sterility.