Advances in application of genome editing in tomato and recent development of genome editing technology

Abstract

Genome editing, a revolutionary technology in molecular biology and represented by the CRISPR/Cas9 system, has become widely used in plants for characterizing gene function and crop improvement. Tomato, serving as an excellent model plant for fruit biology research and making a substantial nutritional contribution to the human diet, is one of the most important applied plants for genome editing. Using CRISPR/Cas9-mediated targeted mutagenesis, the re-evaluation of tomato genes essential for fruit ripening highlights that several aspects of fruit ripening should be reconsidered. Genome editing has also been applied in tomato breeding for improving fruit yield and quality, increasing stress resistance, accelerating the domestication of wild tomato, and recently customizing tomato cultivars for urban agriculture. In addition, genome editing is continuously innovating, and several new genome editing systems such as the recent prime editing, a breakthrough in precise genome editing, have recently been applied in plants. In this review, these advances in application of genome editing in tomato and recent development of genome editing technology are summarized, and their leaving important enlightenment to plant research and precision plant breeding is also discussed.

Keywords: CRISPR; Cas9; Gene function; Precision plant breeding; Solanum lycopersicum.

Fig. 1

Working models of conventional CRISPR/Cas9 (a) and recent prime editing (b). TracrRNA, transactivation RNA; crRNA, CRISPR-RNA; sgRNA, small-guide RNA; PAM, protospacer adjacent motif; NHEJ, non-homologous end joining; HDR, homology-directed repair; pegRNA, prime editing guide RNA; RT, reverse transcription; PBS, primer-binding site; nCas9 (H840A), catalytically impaired Cas9 (H840A) nickase (nCas9); M-MLV-RT, Moloney murine leukemia virus reverse transcriptase

Fig. 2

A chart illustrating the applications of genome editing in tomato improvement