An optimized procedure for plant recovery from somatic embryos significantly facilitates the genetic improvement of Vitis

Abstract

Plant regeneration from grapevine (Vitis spp.) via somatic embryogenesis typically is poor. Recovery of plants from Vitis rotundifolia Michx. (muscadine grape) is particularly problematic due to extremely low efficiency, including extended culture durations required for embryo–plant conversion. Poor plant recovery is an obstacle to the selection of improved genetically modified lines. Somatic embryos (SEs) of V. rotundifolia cultivar Delicious (Del-HS) and Vitis vinifera L cultivar Thompson Seedless (TS) were used to identify culture media and conditions that promoted embryo differentiation and plant conversion; this resulted in a two-step culture system. In comparative culture experiments, C2D medium containing 6% sucrose was the most effective, among four distinct formulae tested, for inducing precocious SE germination and cell differentiation. This medium, further supplemented with 4 µM 6-benzylaminopurine (C2D4B), was subsequently determined to enhance post-germinative growth of SE. MS medium supplemented with 0.5 µM 1-naphthaleneacetic acid (MSN) was then utilized to stimulate root and shoot growth of germinated SE. An average of 35% and 80% ‘Del-HS’ and ‘TS’ SE, respectively, developed into plants. All plants developed robust root and shoot systems and exhibited excellent survival following transfer to soil. Over 150 plants of ‘Del-HS’ were regenerated and established within 2.5 months, which is a dramatic reduction from the 6- to 12-month time period previously required. Similarly, 88 ‘TS’ plant lines were obtained within the same time period. Subsequently, seven out of eight Vitis cultivars exhibited significantly increased plant conversion percentages, demonstrating broad application of the two-step culture system to produce the large numbers of independent plant lines needed for selection of desired traits.

CRISPR/Cas9 Targeted Editing of Genes Associated With Fungal Susceptibility in Vitis vinifera L. cv. Thompson Seedless Using Geminivirus-Derived Replicons

“…Somatic embryogenesis is the most consistent approach for adventitious regeneration, and gene transfer in grapevines has been a continuous focus of development ( Tapia et al, 2009 ; Zhou Q. et al, 2014 ; Saporta et al, 2016 ). Recent research has sought to extend the protocols to varieties ( Carra et al, 2016 ; San Pedro et al, 2017 ), hybrids, and rootstocks ( Oláh et al, 2009 ), including some Vitis species, which were until very recently described as recalcitrant ( Li et al, 2014 ). Transgenic individuals were generated using somatic embryo masses ( Ren et al, 2016 ; Nakajima et al, 2017 ; Wang et al, 2017 ).…”

Producing Transgenic Thompson Seedless Grape (Vitis vinifera) Plants using Agrobacterium tumefaciens

“…NN basal medium supplemented with 2.0 mg L -1 2, 4-D and 0.5 mg L -1 TDZ was the most effective for the induction of callus (92%) and shoot formation (+++). Several studies on Vitis rupestris (Olah et al, 2003), Vitis rotundifolia (Dhekney et al, 2011;Li et al, 2014) and Vitis vinifera (Vidal et al, 2009) has been similarly succeeded to obtain regeneration using leaves as explants. In agreement with our results, Mullaw et al (2010) reported that abundant embryogenic callus in wine grape was obtained from leaf and floral explants supplemented with 9.0 μM 2, 4-D +17.0 μM IASP in combination with either 1.0 μM BA or 1.0 μM TDZ in darkness.…”

Pengaruh Sitokinin, Jenis Eksplan, dan Genotipe terhadap Embriogenesis Somatik Kakao

“…Perbedaan respons embriogenesis somatik di antara genotipe banyak ditemukan pada berbagai jenis tanaman budi daya, di antaranya Vitis vinivera L. (Malabadi, Vijaykumar, Nataraja, & Mulgund, 2010), Vitis spp. (Li et al, 2014), Gossypium spp. (Ghaemi, Majid, Fallahian, & Bezdi, 2011), Ipomea batatas L. (Sefasi et al, 2012) dan Manihot esculenta Crantz (Ngugi et al, 2015;Mongomake, Doungous, Khatabi, & Fondong, 2015).…”