Biopolymers and cell. 1990. Volume 6. № 5. 86 - 90

E. L. Babiychuk, M. A. Bannikova, V. P. Momot, N. N. Cherep, I. K. Komarnitsky, S. G.Kushnir.Yu. Yu. Gleba

NUCLEAR-CYTOPLASMIC INCOMPATIBILITY IN CYBRIDS POSSESSING AN ATROPA BELLADONNA NUCLEAR GENOME AND A NICOTIANA TABACUM PLASTOME

Summary

    Mesophyll protoplasts of the nitrate reductase deficient mutant of tobacco, Nicotiana ia-bacum NiaSO were fused with mesophyll protoplasts of wild type Atropa belladonna. Selection resulted in regeneration of a variegated shoot with morphology similar to that of Atropa. A fully chlorophyll-deficient Atropa-like plants were regenerated from an indi¬vidual leaf sector and called Atropa belladonna Abw. Cytogenetic (chromosome number and morphology) and biochemical (analysis of the multiple molecular forms of amyla-ses and esterases, restriction endonuclease analysis of the chloroplast DNA) studies have proved the cybrid nature of these plants; they possess the genome of Atropa and the. plastome of Nicotiana. Genetic complementation experiments were carried out to study the nature of the chlorophyll deficiency of this cybrid. Firstly, mesophyll pro¬toplasts of the plastome chlorophyll-deficient mutant of tobacco A-15 were fused with those of the cybrid under investigation. As a result, green or variegated tobacco plants with chloroplast DNA of Nicotiana were regenerated. Secondly, plastids of Atropa were transferred to A. belladonna Abw by fusion of Abw protoplasts with gamma-irradiated (500 Gy) protoplasts of the cybrid possessing a Nicotiana genome and an Atropa plasto¬me (Kushnir et al., 1987). Fully green plants of Atropa with homologous plastids were regenerated. Numerous independent chlorophyll-free cybrids combining an Atropa geno¬me and Nicotiana were obtained in additional experiment especially developed to select the transfer of tobacco plastids to A. belladonna nucleus. In addition it is shown that the same Atropa genome is compatible with plastome of phylogenetically closely rela¬ted species Scopolia carniolica. Therefore, it is concluded that plastid DNA of Nicotiana tabacum is unable to support normal plastid differentiation into chloroplasts at the nuclear background of A. belladonna.