Conquering Limitations: Exploring the Factors that Drive Successful Agrobacterium-Mediated Genetic Transformation of Recalcitrant Plant Species

Agrobacterium-mediated transformation is a preferred method for genetic engineering and genome editing of plants due to its numerous advantages, although not all species exhibit transformability. Genetic engineering and plant genome editing methods are technically challenging in recalcitrant crop plants. Factors affecting the poor rate of transformation in such species include host genotype, Agrobacterium genotype, type of explant, physiological condition of the explant, vector, selectable marker, inoculation method, chemical additives, antioxidative compounds, transformation-enhancing compounds, medium formulation, optimization of culture conditions, and pre-treatments. This review provides novel insights into the key factors involved in gene transfer facilitated by Agrobacterium and proposes potential solutions to overcome existing barriers to transformation in recalcitrant species, thereby contributing to improvement programs for these species. This review introduces the key factors that impact the effectiveness of a molecular breeding program using Agrobacterium-mediated transformation, specifically focusing on recalcitrant plant species.