Optimization of agrobacterium‐mediated transformation of sugar beet: Glyphosate and insect pests resistance associated genes

Abstract

Transformation of sugar beet with genes conferring tolerance against biotic stresses might accelerate improvement of new hybrid varieties with respect to root yield. In the present study, the optimization of transformation procedure and the integration of four agronomically important genes were assessed in two sugar beet inbred lines. First, the transformation system was optimized with the Agrobacterium tumefacienes LBA4404 and GV3101 strains harboring a recombinant plasmid vector. The vector was constructed based on pBI121 plasmid containing the cryIA105, cryIIIAa, CP4-epsps and gox genes. The effects of four factors including the strains and growth density of Agrobacterium, inoculation time, and plant lines on the frequency of regeneration were assessed. The adventitious bud excised leaflets were used as explants for tissue culture. A factorial experiment based on completely randomized design was adopted as statistical model. Analysis of variance showed that simple effect of Agrobacterium strain, growth density and inoculation time on regeneration of transgenic plantlets, as well as growth rate × inoculation time interaction had significant effects on regeneration of transgenic plantlets. Means comparison analyses indicated that OD 600 = 0.6 and inoculation time of 15 min were the best conditions for transformation. Totally, more than 330 putative transgenic plantlets were regenerated during transformation. The presence of transgenes in the putative transgenic plants was confirmed by polymerase chain reaction (PCR) analysis. Subsequently, transcription of transgenes was confirmed by Reverse Transcription-PCR analysis. Overall, our results revealed that the modified protocol for transformation could be used successfully to introduce new gene cassettes into sugar beet lines.

Establishment of an Effective in vitro Regeneration System for Sugar Beet (Beta vulgaris L.)

“…It could be an affordable and sustainable way to manage pests and diseases (Nyaboga et al 2015). Moreover, by using genetic engineering to develop new varieties of sugar beet (Beta vulgaris L.) which are more suited to harsh environmental conditions and diseases (Moazami-Goodarzi et al 2020). Therefore, it is important to establish an effective regeneration system, particularly for a crop like sugar beet (Beta vulgaris L.) which is highly recalcitrant.…”

Comparison of survival and pathogenicity of Beauveria bassiana A1-1 spores produced in solid and liquid state fermentation on whitefly nymph, Trialeurodes vaporariorum

“…However, this can be avoided by preculturing the explants before inoculation or by extending the duration of co-culture. Novel hybrid varieties with increased yield can be developed by engineering the tolerance or resistance genes of beet related to a wide range of biotic stresses (Moazami-Goodarzi et al 2020). Production of stress tolerant sugar beet varieties through modern breeding approaches can be considered to be a sustainable and cost-effective method for pest and disease management (Nyaboga et al 2015).…”

Assessment of Gus Expression Induced by Anti-Sense OsPPO Gene Promoter and Antioxidant Enzymatic Assays in Response to Drought and Heavy Metal Stress in Transgenic Arabidopsis thaliana

“…Agronomically, four significant genes, namely cryIA105, cryIIIAa, CP4-epsps, and gox, were engineered in sugar beets to withstand biotic stresses, and improved regeneration of sugar beet plantlets was observed. Agrobacterium tumefaciens LBA4404 and GV3101 strains formed using recombinant plasmids were found to be efficient and suggested inserting new genes in sugar beets [38]. The use of the PPO expression system for the development of stress-tolerant plant species, particularly in crops that may experience harsh simultaneous environmental challenges such as drought, salt, and diseases, appears to be a promising tool for the future.…”