Development and application of gene editing in citrus: how and what to do

Conventional breeding techniques have been effectively utilized for the enhancement of citrus varieties. Nonetheless, traits such as an extended juvenile phase, cross- or self-incompatibility, high genetic heterozygosity, and polyembryony have posed significant challenges and limitations to these methods. The clustered regularly interspaced short palindromic repeats (CRISPR) genome editing has progressively emerged as a vital tool for citrus breeding and research. This article reviews the array of CRISPR/Cas genome editing systems, emphasizes recent advancements in citrus genome editing using CRISPR/Cas, and explores the application of this technology to bolster resistance to citrus canker. The review also covers the development of CRISPR/Cas-mediated transformation and regeneration systems for citrus, alongside approaches for generating transgene-free citrus germplasm. Moreover, the regulatory landscape and societal acceptance of CRISPR/Cas genome editing are examined. Lastly, potential applications of genome editing in citrus breeding are proposed, with attention to prospective challenges.