Complementation between protoplasts treated with either of two metabolic inhibitors results in somatic-hybrid plants

Abstract

When Nicotiana protoplasts are treated with either iodoacetate (IA) or rhodamine 6-G (R6G) and then cultured in vitro they will succumb. It was reported previously that protoplasts treated with either of these metabolic inhibitors and fused with cell-division arrested (x or γ-irradiated) protoplasts, they are metabolically complemented and cybrid plants will ultimately be obtained. In this study we asked whether metabolic complementation can ensue between IA- and R6G-treated protoplasts, thus resulting in the respective somatic-hybrid plants. Two experiments were performed with two pairs of fusion partners. In both experiments the fusion partners had nuclear markers and organelle compositions which provided easy identification of parental plants, cybrids and somatic hybrids. Both experiments indicated clearly that IA-treated and R6G-treated protoplasts did complement each other after fusion and that the expected somatic-hybrid plants were obtained. This methodology thus promises a general procedure to obtain somatic-hybrid plants; it does not require the use of specially constructed fusion partners with specific complementing mutations in either their nuclear genomes or in their plasmones.