Horticulturae (Apr 2025)

Development of a High-Efficiency, Tissue Culture-Independent Genetic Transformation System for <i>Loropetalum chinense</i>

  • Tingting Li,
  • Yi Yang,
  • Yang Liu,
  • Wei Tang,
  • Yang Liu,
  • Damao Zhang,
  • Chengcheng Xu,
  • Xingyao Xiong,
  • Xiaoying Yu,
  • Yanlin Li

DOI
https://doi.org/10.3390/horticulturae11040404
Journal volume & issue
Vol. 11, no. 4
p. 404

Abstract

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Loropetalum chinense is a significant small tree and ornamental shrub known for its colorful foliage and is widely used in landscaping in tropical and subtropical regions. This study aimed to establish an efficient, tissue culture-independent genetic transformation system for L. chinense. Cuttings from two varieties, ‘Xiangnong Xiangyun’ and ‘Hei Zhenzhu’, were infected with different strains of Agrobacterium rhizogenes. The results showed that the K599 strain significantly induced hairy roots in both varieties, with ‘Xiangnong Xiangyun’ demonstrating a higher survival rate (60%), rooting rate (51.66%), and hairy root induction efficiency (45%) compared to ‘Hei Zhenzhu’. Based on these findings, ‘Xiangnong Xiangyun’ and the K599 strain were selected for further optimization through an orthogonal L9 (33) experiment, which focused on optimizing the infection solution composition, bacterial concentration, and infection duration, Finally, the genetic transformation system established at the beginning of the experiment was validated on ‘Xiangnong Xiangyun’ plants using the pre-screening LcDREB-43 gene of our group. Among these factors, infection duration was identified as the most influential for improving transformation efficiency. The optimal conditions were determined as an infection solution containing MES solution, a bacterial concentration of OD600 = 0.8, and a 15 min infection duration. Under these optimized conditions, the survival rate, rooting rate, induction efficiency, and transformation efficiency reached 86.67%, 70%, 61.67%, and 43.33%, respectively. Furthermore, the transgenic plants with LcDREB-43 overexpression and pCAMBIA1305-GFP were obtained through the established transformation system, the authenticity of the system was proved, and the production application was carried out through phenotypic observation, molecular identification, and auxiliary verification of physiological indicators.

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