Plants (May 2023)

Efficient Plant Regeneration System from Leaf Explant Cultures of <i>Daphne genkwa</i> via Somatic Embryogenesis

  • Seong Sub Ku,
  • Hyun-A Woo,
  • Min Jun Shin,
  • Eun Yee Jie,
  • HyeRan Kim,
  • Hyun-Soon Kim,
  • Hye Sun Cho,
  • Won-Joong Jeong,
  • Moon-Soon Lee,
  • Sung Ran Min,
  • Suk Weon Kim

DOI
https://doi.org/10.3390/plants12112175
Journal volume & issue
Vol. 12, no. 11
p. 2175

Abstract

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This study aimed to establish an efficient plant regeneration system from leaf-derived embryogenic structure cultures of Daphne genkwa. To induce embryogenic structures, fully expanded leaf explants of D. genkwa were cultured on Murashige and Skoog (MS) medium supplemented with 0, 0.1, 0.5, 1, 2, and 5 mg·L−1 2,4-dichlorophenoxyacetic acid (2,4-D), respectively. After 8 weeks of incubation, the highest frequency of embryogenic structure formation reached 100% when the leaf explants were cultivated on MS medium supplemented with 0.1 to 1 mg·L−1 2,4-D. At higher concentrations of 2,4-D (over 2 mg·L−1 2,4-D), the frequency of embryogenic structure formation significantly declined. Similar to 2,4-D, indole butyric acid (IBA) and α-naphthaleneacetic acid (NAA) treatments were also able to form embryogenic structures. However, the frequency of embryogenic structure formation was lower than that of 2,4-D. In particular, the yellow embryonic structure (YES) and white embryonic structure (WES) were simultaneously developed from the leaf explants of D. genkwa on culture medium containing 2,4-D, IBA, and NAA, respectively. Embryogenic calluses (ECs) were formed from the YES after subsequent rounds of subculture on MS medium supplemented with 1 mg·L−1 2,4-D. To regenerate whole plants, the embryogenic callus (EC) and the two embryogenic structures (YES and WES) were transferred onto MS medium supplemented with 0.1 mg·L−1 6-benzyl aminopurine (BA). The YES had the highest plant regeneration potential via somatic embryo and shoot development compared to the EC and WES. To our knowledge, this is the first successful report of a plant regeneration system via the somatic embryogenesis of D. genkwa. Thus, the embryogenic structures and plant regeneration system of D. genkwa could be applied to mass proliferation and genetic modification for pharmaceutical metabolite production in D. genkwa.

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