Biology Seminar - Daniel Voytas

Abstract:

Plant gene editing is usually carried out by delivering reagents such as Cas9 and sgRNAs to

explants in culture. Edited cells are then induced to differentiate into whole plants by

exposure to various hormones. Creating edited plants through tissue culture is often

inefficient, requires considerable time, only works with limited species and genotypes and

causes unintended changes to the genome and epigenome. We have been pursuing

alternative approaches for plant gene editing that minimize or obviate the need for tissue

culture. In one approach, we generate gene edited dicotyledonous plants through de novo

meristem induction. Developmental regulators and gene editing reagents are delivered to

somatic cells on whole plants. Meristems are induced that produce shoots with targeted

DNA modifications, and gene edits are transmitted to the next generation. In a second

approach, we use RNA viruses to deliver sgRNAs through infection to transgenic plants

that express Cas9. The sgRNAs are augmented with sequences that promote cell-to-cell

mobility and movement into the meristem. Gene edited shoots are thus generated that

transmit gene edits to the next generation. Because both approaches minimize the need

for tissue culture, they promise to help overcome this bottleneck in plant gene-editing.