Establishment of a PEG-mediated Maize Root Protoplast Transformation System


  • Mariela Alfaro Garcia, , Iowa State University

Faculty Mentor(s)

  • Erin Sparks, Department of Plant and Soil Sciences, University of Delaware
  • Jingjing Tong, Department of Plant and Soil Sciences, University of Delaware


Plant protoplasts are an important and versatile cell system. And protoplast transformation is widely used in the characterization of gene functions. Maize is one of the most widely cultivated staple crops worldwide and an important model system for studying plant genetics, genetic engineering, and biosynthesis. In previous studies, maize protoplast transformation majorly utilized maize mesophyll protoplast, and rarely did studies on the maize root protoplast. Compared with mesophyll protoplast transformation, root protoplast transformation has a low and labile transformation efficiency. In our study, we aim to establish a higher and steadier transformation efficiency in maize root protoplast. There are two main parts in our bench work: maize root protoplast isolation and transformation. In protoplast isolation, we have successfully isolated maize root protoplasts from maize seedlings’ root tips. Meanwhile, we utilize E. coli cell culture to yield huge amounts of plasmids for protoplast transformation. In the transformation, we use the PEG-mediated transformation approach, which is commonly used in protoplast transformation because it is a gentle way and causes less damage to fragile protoplasts. In order to increase the transformation efficiency, we tested various set-ups with various treatment times, different concentrations of protoplasts, and different amounts of plasmids. A higher and steadier transformation efficiency in the maize root protoplast transformation system will provide a novel cell type for maize protoplast transformation and gene function characterization.