<i>Agrobacterium rhizogenes</i> ‐Mediated Hairy Root Transformation for Genome Editing in Recalcitrant Legume <i>Lathyrus sativus</i>

Lathyrus sativus, commonly known as the grass pea, is a nutritious legume that is resilient to climate change, allowing it to grow in drought, waterlogged, and saline soils. However, developing effective functional genomic tools for this crop has been challenging, primarily due to the absence of reliable and stable transformation protocols. Agrobacterium rhizogenes-mediated hairy root transformation provides a practical and rapid method for validating gene functions using the CRISPR/Cas system. This method has not been applied to grass pea despite its potential. In this article, we present the first protocol for A. rhizogenes-mediated hairy root transformation and CRISPR/Cas genome editing aimed at the functional characterization of candidate genes in L. sativus. © 2025 Wiley Periodicals LLC. Basic Protocol 1: Designing CRISPR/Cas9 construct for targeted gene editing in L. sativus Support Protocol 1: Escherichia coli competent cell preparation and transformation Support Protocol 2: A. rhizogenes competent cell preparation and transformation Basic Protocol 2: A. rhizogenes-mediated hairy root transformation in L. sativus Basic Protocol 3: Screening of transgenic hairy root lines Support protocol 3: DNA isolation from L. sativus hairy roots.