Chinese Bulletin of Botany ›› 2020, Vol. 55 ›› Issue (1): 9-20.DOI: 10.11983/CBB19133

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Transformation of Insect Derived Antifreeze Gene into Sweet Potato (Ipomoea batatas) and Enhanced Its Freeze-tolerance

Xianjun Lai1,Yizheng Zhang2,Yinghong Gu2,Lang Yan1,*()   

  1. 1Sichuan Key Laboratory of Potatoes, College of Agriculture Science, Xichang College, Liangshan 615013, China
    2Sichuan Key Laboratory of Molecular Biology & Biotechnology, College of Life Science, Sichuan University, Chengdu 610064, China
  • Received:2019-07-05 Accepted:2019-09-24 Online:2020-01-01 Published:2019-12-20
  • Contact: Lang Yan

Abstract: To explore whether the gene encoding antifreeze protein from insect can enhance the freezing tolerance of sweet potato through gene transformation, and to prepare freeze-tolerance materials for breeding purposes, we constructed a plant gene expression vector harboring an antifreeze gene TmAFP from yellow mealworms (Tenebrio molitor) and obtained transgenic freeze-tolerance sweet potato lines using Agrobacterium-mediated transformation method. A high-frequency regeneration system of sweet potato was established using the variety Huachano as the recipient material, and the embryogenic suspension cells were cultured in the somatic embryo maturation medium. The sensitivity test of embryogenic cells to herbicides indicated that the combination of MS+0.2 mg·L -12,4-D+0.8 mg·L -1GAP+100 mg·L -1Carb is the most effective medium for screening the transgenic positive plants. Seven embryogenic calli were obtained and 42 resistant seedlings were regenerated, among which 23 harbored pSUIBEV3-AFP and 19 had pCAMBIA-AFP. All resistant seedlings were examined by PCR, Southern hybridization and RT-PCR, and the results showed that the TmAFP gene was integrated into the plant genome and expressed. The transgenic and non-transgenic plants were treated at -1°C for 15 hours, and then transferred to room temperature. The results demonstrated that the freeze-tolerance of the transgenic plants was greatly improved.

Key words: sweet potato, antifreeze protein, transgenic, plant regeneration of sweet potato, molecular breeding