Agrobacterium rhizogenes-mediated genetic transformation in Cichorium spp.: hairy root production, inulin and total phenolic compounds analysis

ABSTRACT

Chicory (Cichorium spp.) is a valuable vegetable crop worldwide for its edible leaves and for the production of coffee substitutes from roots. Agrobacterium rhizogenes-mediated genetic transformation of two species of chicory (C. intybus and C. endivia) was investigated using Agrobacterium strain K599 harbouring p35SGFPGUS+ plasmid and two types of explants: leave and leaf stalks. This Agrobacterium strain proved to be competent in the transformation with transformation rate about (23.1%) in leaf explants of C. intybus. However, the transformation rate with C. endivia was much lower (3.6%). Moreover, the hairy roots appeared from different infection sites of the leaf explants. Several hairy roots of the two species were acquired, out of them 11 clones (C. intybus) and two clones (C. endivia) were selected due to their fast-growing character. Growth of hairy roots was determined on the basis of total root biomass accumulation. It was found that the liquid MS-basal medium seems to be the most suitable for biomass production. PCR analysis revealed foreign DNA integration in the selected transgenic hairy root clones. Notable, the transgenic hairy roots exhibited substantially higher growth rates and accumulated higher amount of inulin than non transgenic roots (WT). Also, the total phenolic compounds were determined.

KEYWORDS:

• Chicory
• hairy roots culture
• inulin
• phenolic compound
• Agrobacterium rhizogenes

Acknowledgements

We sincerely thank National Research Centre (NRC) -Egypt, for financial support. We gratefully acknowledge Dr. Georgina Estrada-Navarrete, Departamento de Biologia Molecular de plantas, Instituto de Biotecnologia, Universidad Nacional Autónoma de México for kindly providing the bacterial strain and p35SGFPGUS+ plasmid.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Research Centre (NRC)