AUTHOR=Moon Ki-Beom , Park Su-Jin , Park Ji-Sun , Lee Hyo-Jun , Shin Seung Young , Lee Soo Min , Choi Gyung Ja , Kim Sang-Gyu , Cho Hye Sun , Jeon Jae-Heung , Kim Yong-Sam , Park Youn-Il , Kim Hyun-Soon 

TITLE=Editing of StSR4 by Cas9-RNPs confers resistance to Phytophthora infestans in potato

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.997888

DOI=10.3389/fpls.2022.997888

ISSN=1664-462X

ABSTRACT=<p>Potato (<italic>Solanum tuberosum</italic> L.) cultivation is threatened by various environmental stresses, especially disease. Genome editing technologies are effective tools for generating pathogen-resistant potatoes. Here, we established an efficient RNP-mediated CRISPR/Cas9 genome editing protocol in potato to develop <italic>Phytophthora infestans</italic> resistant mutants by targeting the susceptibility gene, <italic>Signal Responsive 4</italic> (<italic>SR4</italic>), in protoplasts. Mutations in <italic>StSR4</italic> were efficiently introduced into the regenerated potato plants, with a maximum efficiency of 34%. High co-expression of <italic>StEDS1</italic> and <italic>StPAD4</italic> in <italic>stsr4</italic> mutants induced the accumulation of salicylic acid (SA), and enhanced the expression of the pathogen resistance marker <italic>StPR1</italic>. In addition, increased SA content in the <italic>stsr4</italic> mutant enhanced its resistance to <italic>P. infestans</italic> more than that in wild type. However, the growth of <italic>stsr4_3-19</italic> and <italic>stsr4_3-698</italic> mutants with significantly high SA was strongly inhibited, and a dwarf phenotype was induced. Therefore, it is important to adequate SA accumulation in order to overcome <italic>StSR4</italic> editing-triggered growth inhibition and take full advantages of the improved pathogen resistance of <italic>stsr4</italic> mutants. This RNP-mediated CRISPR/Cas9-based potato genome editing protocol will accelerate the development of pathogen-resistant <italic>Solanaceae</italic> crops <italic>via</italic> molecular breeding.</p>