Production of transgenic Paulownia tomentosa (Thunb.) steud. using chitosan nanoparticles to express antimicrobial genes resistant to bacterial infection

Promoting genotype-independent plant transformation by manipulating developmental regulatory genes and/or using nanoparticles

KEY MESSAGE

This review summarizes the molecular basis and emerging applications of developmental regulatory genes and nanoparticles in plant transformation and discusses strategies to overcome the obstacles of genotype dependency in plant transformation. Plant transformation is an important tool for plant research and biotechnology-based crop breeding. However, Plant transformation and regeneration are highly dependent on species and genotype. Plant regeneration is a process of generating a complete individual plant from a single somatic cell, which involves somatic embryogenesis, root and shoot organogeneses. Over the past 40 years, significant advances have been made in understanding molecular mechanisms of embryogenesis and organogenesis, revealing many developmental regulatory genes critical for plant regeneration. Recent studies showed that manipulating some developmental regulatory genes promotes the genotype-independent transformation of several plant species. Besides, nanoparticles penetrate plant cell wall without external forces and protect cargoes from degradation, making them promising materials for exogenous biomolecule delivery. In addition, manipulation of developmental regulatory genes or application of nanoparticles could also bypass the tissue culture process, paving the way for efficient plant transformation. Applications of developmental regulatory genes and nanoparticles are emerging in the genetic transformation of different plant species. In this article, we review the molecular basis and applications of developmental regulatory genes and nanoparticles in plant transformation and discuss how to further promote genotype-independent plant transformation.

Production of transgenic Allium cepa by nanoparticles to resist Aspergillus niger infection

BACKGROUND

Transgenic plants are becoming a more powerful tool in modern biotechnology. Genetic engineering was used in biotech-derived products to create genetically modified (GM) plants resistant to diseases. The onion (Allium cepa, L.) is a common, important perennial vegetable crop grown in Egypt for food and economic value. Onions are susceptible to a variety of fungal infections and diseases. Aspergillus niger is a common onion phytopathogen that causes diseases such as black mould (or black rot), which is a major issue, particularly when exporting onions. A. niger grows between the bulb's outer (dead, flaky) skin and the first fleshy scales, which become water-soaked. Thionin genes produce thionin proteins, which have antimicrobial properties against a variety of phytopathogens, including A. niger. Chitosan nanoparticles act as a carrier for the thionin gene, which allows A. cepa to resist infection by A. niger.

METHODS AND RESULTS

Thionin gene (Thio-60) was transformed into A. cepa to be resistance to fungal infection. The gene was loaded on chitosan nanoparticles to be transformed into plants. Transgenic A. cepa had a 27% weight inhibition compared to non-transgenic one, which had a 69% inhibition. The expressed thionin protein has a 52% inhibitory effect on A. niger spore germination. All these findings supported thionin protein's antifungal activity as an antimicrobial peptide. Furthermore, the data presented here demonstrated the efficacy of chitosan nanoparticles in gene transformation.

CONCLUSION

The present study describes the benefits of producing transgenic onion resistance to black rot diseases via expression of thionin proteins.