Genetic Transformation in Sugar Beet (Beta vulgaris L.): Technologies and Applications

Sugar beet (Beta vulgaris L.) is a potential cash crop of immense commercial importance. The crop finds many industrial utilizations owing to its rich carbohydrate storage reserves. Conventional strategies bank on traditional cultivation package of practices and hence expose the otherwise recalcitrant sugar beet crop to various stresses like diseases, pests, and abiotic stress factors. Hence, potential alternative transpiring to the rescue is the development of genetically transformed crop plants (supplemented by an efficient in vitro regeneration protocol) harbouring beneficial genes to counter the above-mentioned problems. Sugar beet could be genetically modified through the indirect methods using Agrobacterium spp. along with the direct transformation methods, viz. particle bombardment, polyethylene-glycol mediated, somatic hybridization, sonication, and electroporation. Such biotechnological explorations aim towards the development of improved herbicide -resistant, salinity-tolerant, frost and moisture stress-resistant, rhizomania-, Cercospora leaf spot- and nematode-resistant lines along with concerted efforts to augment the intrinsic secondary metabolites. Industrially important carbohydrates like fructans and sucrose have also been improvised via transgenic interventions. With the multi-dimensional prospects of genetic engineering in sugar beet being explored since the early 1990s, the different investigative attempts along with the associated underlying reasons and parameters to the derived results have been discusse in the current review that effectively summarizes the different transformation techniques employed along with the potential applications of the transformed plants for crop improvement in sugar beet with major focus on biotic and abiotic stress tolerance.