Sugar beet transformation protocol achieves high direct shoot regeneration

Researchers have developed an Agrobacterium tumefaciens-mediated transformation protocol for sugar beet (Beta vulgaris L.) that bypasses the callus stage and uses direct shoot regeneration from leaf explants. In the reported experiments, the system achieved a maximum regeneration efficiency of 91.67% and produced an average of 10.33 shoots per explant, while regenerated plants exhibited low somaclonal variation. The method is intended to address the difficulties that sugar beet has presented for in vitro regeneration and genetic engineering.

By regenerating shoots directly from leaf tissue, the workflow reduces the number of culture stages required before whole plants are recovered. The study combines this regeneration route with systematically optimized bacterial infection conditions and antibiotic selection, then confirms the resulting plants through molecular assays. Under the most effective conditions tested, 91.67% of explants regenerated shoots, with an average of 10.33 shoots per explant.

No callus phase was required, and the regenerated plants showed low somaclonal variation, indicating that the direct-organogenesis workflow retained a comparatively stable plant population in these experiments. The bacterial infection stage was optimized in a systematic series of trials. These values describe the conditions identified as optimal within the study’s experimental system; they do not establish that the same settings will be equally effective in every sugar beet variety or laboratory context.

Selection conditions also influenced recovery of transformed shoots. The researchers found that a low kanamycin concentration of 60 mg/L was critical to the optimized protocol, reducing phytotoxicity without compromising selection effectiveness among the conditions examined. The reported workflow began with leaf explants, used direct shoot regeneration after Agrobacterium infection, and applied kanamycin selection to recover plants carrying the introduced genetic material.

Transformation was assessed with three complementary molecular approaches. Polymerase chain reaction was used to identify transgene integration, reverse-transcription quantitative PCR was used to assess transgene expression, and histochemical GUS staining was used to detect reporter activity in transformed tissue. These analyses provided evidence of the presence and expression of introduced DNA rather than relying only on plant survival during antibiotic selection.

Among the transgenic plants produced in the study, 70% acclimatized successfully after transfer from tissue culture. The authors described this survival rate as higher than rates previously reported for Beta vulgaris. The combination of direct shoot regeneration, 91.67% maximum regeneration efficiency, low observed somaclonal variation, molecular confirmation of transgene integration and expression, and successful acclimatization forms the principal result of the research.

The protocol is a laboratory research tool rather than a demonstrated crop-improvement outcome. It may support functional genomics studies by providing a route for introducing and detecting genes in sugar beet, and the authors identify potential applications in efforts to enhance the crop’s genetic value. Within the scope of the reported study, the work offers a streamlined direct-regeneration system with a high shoot yield under the tested culture conditions.

Its immediate value lies in the measured laboratory performance: direct formation of shoots without a callus phase, optimized Agrobacterium infection parameters, effective selection at 60 mg/L kanamycin, molecular verification of transgenic plants and a 70% acclimatization rate. The authors present the procedure as a potential foundation for functional genomics and further genetic studies in sugar beet, while the extent of its usefulness beyond the tested system remains to be determined by subsequent research.

Subject of Research: Laboratory development of an Agrobacterium-mediated sugar beet transformation protocol using direct shoot regeneration

Article Title: Establishment of an efficient and genetically stable Agrobacterium-mediated transformation protocol for Beta vulgaris L. (sugar beet) based on direct shoot regeneration

Article References: Husain, Z., Aqsa, A., Guo, H., Wang, Y., Leng, X., & Liao, H. (2026). Establishment of an efficient and genetically stable Agrobacterium-mediated transformation protocol for Beta vulgaris L. (sugar beet) based on direct shoot regeneration. BMC Plant Biology. https://doi.org/10.1186/s12870-026-10221-5

Image Credits: AI Generated

DOI: 10.1186/s12870-026-10221-5

Keywords: sugar beet, Beta vulgaris, Agrobacterium, plant transformation, direct organogenesis, shoot regeneration, tissue culture, kanamycin selection, transgenic plants, functional genomics, Establishment, efficient