Non-tissue culture genetic modifications for plant improvement

Gene delivery systems are essential for investigating gene regulation mechanisms and enhancing the genetic improvement of functional traits in plants. However, fewer than 0.1% of higher plant species on Earth can be genetically modified. Even for these species, the genetic modification process relies on complex tissue culture methods, which are time-consuming, costly, and often require specialized technical skills. Additionally, the efficiency of genetic modification is extremely low in some species. Notably, over the past five years, significant progress has been made in establishing non-tissue culture genetic modification systems. This advancement effectively resolved a series of previously mentioned challenges and innovated in biotechnology for the improvement of many valuable plant species. This review summarizes the research advancements in non-tissue culture genetic modification technologies and presents examples of successful species modified using various methods, including fast-treated Agrobacterium co-culture (Fast-TrACC), cut-dip-budding (CDB), particle bombardment, and nano-mediated delivery systems. Additionally, we propose a working guideline to classify, analyze, evaluate, and select non-tissue culture genetic modification systems for plant species of interest. Our review also discusses the potential for enhancing plant regeneration capacity, improving genetic modification efficiency, and the future application prospects for plant improvement.