Cell strains and plant material
Suspension cultures of Vitis rupestris (Seibicke et al., 2002),
and a transgenic cell line of V. vinifera ‘Chardonnay’,
expressing the fluorescent actin marker GFP-AtFABD2 (Akaberi et
al., 2018), were cultivated in liquid medium containing 4.3
g.L-1 Murashige and Skoog salts
(Duchefa, Haarlem, The Netherlands), 30 gL-1 sucrose,
200 mg.L-1KH2PO4, 100
mg.L-1 inositol, 1
mg.L-1 thiamine, and 0.2
mg.L-1 2,4-dichlorophenoxy-acetic
acid (2,4-D), pH 5.8. The cells were subcultured weekly, inoculating 6
ml of stationary cells into 30 ml of fresh medium in 100 ml Erlenmeyer
flasks and incubated at 27°C in the dark at 150 rpm on a horizontal
shaker (KS250 basic, IKA Labortechnik, Staufen, Germany). For
cultivation of the transgenic actin marker line, the medium was
supplemented with kanamycin (50
mg.L-1). Since aluminium readily
partitions into inactive complexes at neutral pH, especially in complex
media, the complex MS medium was replaced by a acidified (pH 4.5)
sucrose solution complemented with 3 mM CaCl2 (Ikegawa
et al. , 2000).
The Vitis vinifera ssp. sylvestris genotype ‘Hö29’, and
the V. vinifera ssp. vinifera variety ‘Augster Weiss’ were
cultivated and collected from the grapevine germplasm collection of the
Botanical Garden of the Karlsruhe Institute of Technology.