Microbead encapsulation of living plant protoplasts: A new tool for the handling of single plant cells1

PREMISE OF THE STUDY Understanding plant cell biomechanics has been hampered by a lack of appropriate experimental tools. Here we introduce a protocol for the incorporation of individual plant protoplasts into precisely sized agarose microbeads. This technology may lead to new ways to manipulate the physical and chemical microenvironment of individual plant cells. METHODS AND RESULTS Living protoplasts obtained from BY-2 tobacco suspension cultures were continuously incorporated into a stream of agarose microdroplets, collected in cooled mineral oil as gelled microbeads, and then transferred into liquid MS medium for culture. In this first report, we show that spherical microbeads containing living protoplasts can be easily generated in quantity and that these encapsulated cells continue to grow and divide. CONCLUSIONS Microbead encapsulation of protoplasts affords the opportunity to precisely control the physical microenvironment of individual plant cells. Ultimately, this method may help facilitate novel studies in plant biomechanics.