Protoplast culture fusion

The use of protoplasts in studies of stress physiology and biochemistry expands the advantages of cell culture systems discussed in the preceding sections. Additional applications are related to the fusion of protoplasts. Intraspecifie and interspecific protoplast fusion greatly enhance genetic variability of the fused protoplasts (Kumar Cocking, 1987). The resulting somatic hybrids provide cells which can be used for selection of specific traits (e.g. environmental stress tolerance) provided by one or both donor cells and for basic studies on cytoplasmic and nuclear inheritance of desired characteristics. 

Nishihara, and M. Kito. Phospholipids of membranes of cultured cells and the products of protoplast fusion. Phytochemistry 1979 18 423-426. 

Protoplast fusion has also been successfiilly used to produce novel mold isoprenoids, such as citreoanthrasteroids and citreohybridones (Nakada 2000). Long chain aldehydes, valuable as a bio-flavor, have also been secured along similar procedures fiom tMli cultures of the green seaweed Ulva pertusa, regenerated fiom protoplasts (Fujimura 1990). 

The cultivated potato and many of its relatives are amenable to eell and tissue culture procedures, ineluding protoplast isolation and fusion. Somatic cell fusions have frequently been used to eombine the genomes of Solarium speeies that are sexually ineompatible because of pollen-stylar interactions or mismatched EBN numbers. Somatic fusion circumvents sexual reproduetion and results in novel eombinations of not only nuclear genomes, but also cytoplasmic genomes (Trabelsi et al., 2005 Bidani et al., 2007 Lovene et al., 2007). However, recalcitrant genotypes... 

Obviously the next question involves the transfer of resistance. If crosses are made between the Baccharis species will resistance be imparted to the offspring What sort of Mendelian ratios might be found Would this better be accomplished by protoplast fusion and tissue culture Can this resistance be transferred to other genera Is there a practical application (herbicide incorporation into seed) for this discovery Do the genes that enable B. megapotamica to handle the trichothecenes exist in B. halimifolia and, if they do, what turns them on or off There is some exciting work yet to be done in this area of research. And we have now entered the next topic. 

Genetic techniques for obtaining chloroplast-encoded herbicide resistance in crop plants are reviewed. These are based on the use of cell culture methods and Include mutant selection in cultured cells, chloroplast transfer via protoplast fusion, and genetic recombination between chloroplast genomes. The first two methods are described in detail using trlazine resistance as an example. 

Cell culture-based methods suitable for obtaining chloroplast-encoded herbicide resistance in crops will be reviewed. These will Include mutant selection in cultured cells, transfer of chloroplasts via protoplast fusion, and selection of recombinant chloroplast genomes. Examples will be limited to resistance to triazine herbicides. Chloroplast transformation involving introduction of novel DNA into chloroplasts, will not be covered. Preliminary data indicate that chloroplast transformation may be feasible (4) but have not been confirmed. The genetics, physiology... 

Sumitomo Chemical. Jpn. Kokai Tokkyo Koho. JP 55096096, 21-07-1980. JP 79-4275 16-01-1979. Enhancement of protoplast fusion in plant cell cultures (Rauvolfia serpentina). Chem. Abstr. 93, 218142q. 

Behera BC, Sonone A, Makhija U (2009b) Protoplast isolation from cultured lichen Usnea ghattensis, their fusion with protoplasts of Aspergillus nidulans, fusant regeneration and production of usnic acid. Folia Microbiol 54 415-418 Behera BC, Mahadik N, Morey M (2012) Antioxidative and cardiovascular-protective activities of metabolite usnic acid and psoromic acid produced by lichen species Usnea complanata under submerged fermentation. Pharm Biol 50 968-979 Bezivin C, Tomasi S, Rouaud I et al (2004) Cytotoxic activity of compounds from the lichen Cladonia convoluta. Planta Med 70 874-877... 

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