Related Experiment Video
Updated: Jun 4, 2026

Hairy Root Transformation and Regeneration in Arabidopsis thaliana and Brassica napus
Published on: December 22, 2023
Effect of the number of rol genes integrations on phenotypic variation in hairy root-derived Hypericum perforatum L.
Hedviga Komarovská1, Ján Kosuth, Annalisa Giovannini
1P. J. Safárik University, Faculty of Science, Institute of Biology and Ecology, Mánesova 23, 041 54 Kosice, Slovakia.
Abstract:
The extent of phenotypic variation of St. John's wort (Hypericum perforatum L.) plants transformed with wild agropine ATCC 15834 Agrobacterium rhizogenes plasmid was evaluated with respect to the number of rol genes integrations. The transfer of T(L)-DNA to plant explants during each transformation event was incomplete with different rolA, rolB, and rolC copy numbers. Along with typical features representing the hairy root syndrome, an altered size, number and density of dark and translucent glands, changes in ability to synthesize secondary metabolites, and reduced fertility were observed. The highest copy number of transferred rol genes resulted in weak expression of transgenic character and comparable quantitative parameters with the controls. Only 1 out of 11 transgenic clones was able to produce seed progeny and not more than 4 out of its 35 offsprings were positive for rolC gene integration. Sterility of the clones was due to retarded development of both gametophytes.
Related Concept Videos
Trihybrid Crosses
Some of Mendel’s crosses examined three pairs of contrasting characteristics. Such a cross is called a trihybrid cross. A trihybrid cross is a combination of three individual monohybrid crosses. For example, plant height (tall vs. short), seed shape (round vs. wrinkled), and seed color (yellow vs. green).
The F1 generation plants of a trihybrid cross are heterozygous for all three traits and produce eight gametes. Upon self-fertilization, these gametes have an equal chance to...
Epistasis
Transgenic Plants
The first-ever transgenic plant was a tobacco plant developed in 1983 that showed resistance against the tobacco mosaic virus. Since then, many transgenic plants have been developed and commercialized for improving the agricultural, ornamental, and horticultural value of a crop plant. Transgenic...
Dihybrid Crosses
Position-effect Variegation
Chi-square Analysis
The chi-square test was developed by Pearson in 1990.
The first step of performing a Chi-square analysis is to establish a null hypothesis, which assumes that there is no real...
