Aug 2026· Plant Innovation Journal· Vol 1, pp. 118-125· 0 citations· 29 references
TL;DR
This review proposes that these constraints are functionally coupled through the intracellular abundance, nuclear access, and chromatin residence time of active Cas-gRNA complexes, which could lead to convergent biochemical solutions spanning herbaceous and woody species.
Abstract
CRISPR-Cas platforms have transformed plant functional genomics, yet nucleases such as Cas9 and Cas12a remain constrained by two seemingly distinct limitations: imperfect target discrimination and inefficient intracellular delivery. Here, this review proposes that these constraints are functionally coupled through the intracellular abundance, nuclear access, and chromatin residence time of active Cas-gRNA complexes. Off-target activity arises from guide-target mismatch tolerance during R-loop formation, whereas rigid plant cell walls constrain the delivery of RNP and DNA cargo. These processes can become coupled when delivery limitations alter the concentration or duration of active Cas-gRNA exposure. When inefficient delivery is addressed through sustained or elevated nuclease expression, it can increase cumulative active Cas-gRNA exposure and may consequently increase off-target risk. Evidence from maize, rice, wheat, and carrot systems is synthesized and convergent biochemical solutions, including transgene-free RNP delivery, are outlined spanning herbaceous and woody species.
Abstract Selective and tunable regulation of clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a activity enables on-demand control, yet current strategies remain hindered by nonspecific regulation and limited tunability. Inspired by proximity effect, we present a Cas-regulation-targeting chimera (CasTAC) strategy that employs CRISPR RNA (crRNA) as a proximity mediator to carry phosphorothioate regulators to interfere with catalytic or recognition domains of Cas12a and consequently suppress its activity. This crRNA-induced proximity approach can effectively eliminate nonspecific interaction between phosphorothioate regulators and proteins within complex multi-enzyme systems, thereby enabling selective control over CRISPR/Cas12a activity. Furthermore, CRISPR/Cas12a activity can be finely tuned to different inhibitory levels by varying the number of phosphorothioate regulators. The CasTAC strategy also improves nuclease resistance and single-nucleotide discrimination, offering potential advances in the sensitivity of molecular diagnostics and the accuracy of gene editing. Notably, the CasTAC balances the kinetics of nucleic acid amplification and CRISPR cleavage, facilitating efficient product accumulation and resolving compatibility issues in one-pot assays. As a proof of concept, we develop a one-pot, one-step recombinase polymerase amplification–CasTAC assay that achieves over 1000-fold higher detection sensitivity than the conventional one-pot recombinase polymerase amplification−CRISPR/Cas12a assay. The CasTAC strategy provides a versatile framework for fine–tuning Cas activity and advances CRISPR technology toward refined and context-adaptable functionality.
Genomic manipulation has advanced from stochastic nuclease‐mediated disruption toward programmable, deterministic precision. Early clustered regularly interspaced short palindromic repeats (CRISPR) strategies enabled targeted mutagenesis through double‐strand breaks; however, their therapeutic application is limited by genotoxicity, chromosomal instability, and dependence on endogenous repair pathways that are difficult to predict. In this review, we examined the transition from gene editing to genome writing, an approach that decouples genomic modification from host repair pathways to better balance efficiency, precision, and payload delivery. We also discussed the principles of precision technologies, including base and prime editors, and described emerging large‐scale writers, such as CRISPR‐associated transposases and recombinase‐based bridge RNAs, which enable the integration of multi‐kilobase synthetic modules. Beyond enzymatic mechanisms, we further considered the combined use of generative artificial intelligence, structural biology, and novel delivery architectures as potential strategies to overcome current biological limitations. Taken together, these developments point toward Generative Biology, in which computational design and high‐throughput screening transform the genome from a static substrate into a more dynamic model for complex, synthetic functional design.
Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins constitute adaptive immune systems in prokaryotes and have transformed life sciences, precision medicine, and synthetic biology as programmable genome-editing tools. Despite their broad utility, naturally occurring DNA-targeting Cas effectors remain constrained by several intrinsic limitations, including large protein size that complicates delivery, stringent protospacer adjacent motif (PAM) requirements that restrict targetable genomic space, and mismatch tolerance that can lead to off-target activity and potential genotoxicity. These challenges have made Cas protein engineering and the discovery of novel CRISPR and CRISPR-like systems from metagenomic resources central to the development of next-generation genome-editing platforms. This Review places recent advances within an integrated synthetic biology engineering continuum that links natural effector discovery, structure-guided hypothesis generation, high-throughput functional screening, machine learning-enabled model construction, and iterative redesign. This Review summarizes progress in the screening, optimization, and functional engineering of DNA-targeting CRISPR and CRISPR-like effectors, with emphasis on structure-guided rational design, directed evolution coupled with high-throughput screening, bioinformatics- and evolution-guided mining of novel systems from large-scale sequence databases, and artificial intelligence-assisted development. By integrating these strategies, we highlight how CRISPR effector engineering is moving toward design-build-test-learn (DBTL)-inspired workflows that expand the functional landscape of genome-editing technologies and advance genome editing toward improved efficiency, safety, and programmability.
Lingwei She, Zeyu Liang, Qin Zou et al.· ACS Synthetic Biology· 1 citation
This chapter outlines a comprehensive methodology for the design, assembly, and functional assessment of CRISPR/dCas9 systems optimized for tomato to investigate pathogen-associated responses.
Ananya Mukherjee, Shrabani Basak, Raghuvir Singh et al.· Methods in molecular biology· 0 citations
A major focus of this review is the inclusion of recent hybrid systems (VLPs, SORT-LNPs) and the recognition that chemical modification of guide RNAs is a critical parameter for therapeutic success and that hybrid systems and stimuli-responsive nanoparticles are poised to dominate the next 5 years of clinical development.
M. Rezaee, F. Izadi, Saeed Nobaharian et al.· Beni-Suef University Journal...· 0 citations
This article synthesizes contemporary advancements in CRISPR-mediated mammalian genome modification, detailing core mechanisms – such as guide RNA and the Cas9 endonuclease – alongside next-generation modalities, including base and prime editing.
Olga Aldoshina, Dmitriy Lazarev, E. Smirnova· Veterinariya, Zootekhniya i...· 0 citations
