Study demonstrated efficient method for developing improved potato, citrus, wild strawberry, and poplar
Image Credit: created with Open AI, Dall-E
University of Maryland researchers demonstrated their CRISPR-Combo tool could improve the efficiency of gene editing in four perennial plants; potato, citrus, wild strawberry, and poplar. The work overcomes a long-standing bottleneck in efforts to speed development of perennial crop varieties. The research is described in preprint of a paper to be published in the journal Nature Communications.
“This research demonstrated a powerful application of CRISPR-Combo in perennial plants to achieve efficient genome editing in plant cells and promote the development of edited cells to whole plants at faster rates,” said Yiping Qi, a professor of plant science at UMD and a corresponding author of the paper.
Perennial plants, those that live for more than two years, have proven difficult to modify through genome editing, in part because of their lengthy life cycle and the fact that they don’t grow easily into whole plants in the laboratory from gene-edited tissues.
Because of these hurdles, it can take years or even decades to successfully produce a single gene-edited line of a perennial crop like a fruit tree or timber tree, compared to just a few months for annual crops like tomatoes or rice.
To overcome these hurdles, Yiping Qi and his colleagues built on earlier work with CRISPR-Combo, a tool they developed and demonstrated in rice and poplar trees, that enables them to edit and activate multiple genes at a time.
In this new research, the team sought to make gene edits more easily in four perennials while also boosting their ability to regenerate entire plants from gene-edited tissues. First, they used CRISPR activation (CRISPRa), a tool they developed that turns genes on without changing the DNA, to systematically screen for a list of very special genes called morphogenic genes that serve as master regulators or switches that turn large networks of other genes on or off. These regulators dictate how cells divide, specialize, and organize into different tissues, so finding them is like finding the “growth” switch that can make it easier for plants to accept gene edits and grow from cultures in the lab.
At the same time, Qi and his colleagues used the CRISPR-Combo approach to make multiple gene edits modifying some DNA while turning up gene expression elsewhere on the genome. Qi and his team demonstrated their method in four separate experiments using potatoes, citrus, strawberries and poplars. This work demonstrates that combining CRISPRa to identify morphogenic genes and CRISPR-Combo to activate such genes while editing other desired genes, is a powerful and effective method to quickly and efficiently develop new varieties of perennial crops. With this method, scientists will be able to create crops with disease resistance or increased yields.
This research was a collaboration of four UMD research laboratories and outside collaborators. In addition to Yiping Qi, authors from the Department of Plant Science & Landscape Architecture include:
Professors James Culver and Gary Coleman, Assistant Research Professor Gen Li, Post-Doctoral Associates Yanhao Cheng, Ayman Eid, Hong Fang, and Rushil Mandlik.
From the UMD department of Cell Biology and Molecular Genetics: Professor Emerita Zhongchi Liu, and Post Doctoral Associate Lei Guo.
Additional authors include Manikandan Ramasamy and Kranthi Mandadi from Texas A&M AgriLife Research and Extension Center, and Randall Niedz from Agricultural Research Service, U.S. Horticultural Research Laboratory, Ft. Pierce, FL.
