Kazuhiko Miyanaga

Analysis of pigment accumulation heterogeneity in plant cell population by image-processing system.

Plant-cultured cells are often highly heterogeneous in secondary metabolite productivity. The industrial application for large-scale metabolite production requires establishment of a stable high-producing cell line. In this study, image analysis of the individual cell is investigated as a method for evaluation of a heterogeneous cell population, and compared with the conventional method of estimation, which is based on average-cell productivity. Among strawberry cells producing anthocyanins, cells with a wide-range of pigment concentration were observed and maximum anthocyanin content was 10 times higher than the average value. In addition, a change of the frequency distribution was revealed in batch cultivation.

Quantitative determination of cultured strawberry-cell heterogeneity by image analysis: effects of medium modification on anthocyanin accumulation

Cultured plant cells are often highly heterogeneous in terms of secondary metabolite production. We have developed a quantitative determination method that uses an image processing system to estimate such individual cell characteristics as content of the secondary metabolite, anthocyanin. In this study, strawberry cells producing anthocyanins were grown in modified Linsmaier-Skoog medium. Anthocyanin accumulation profiles of individual cells depended on medium compositions and were quantitatively determined using the new method. The modified medium supplemented with riboflavin and high sugar concentration showed a markedly higher anthocyanin accumulation profile and pigmented cell ratio than the other modified media. The maximum content was about 11mg (g-fresh cell weight)(-1), which was three times higher than that in the control medium. Moreover, the anthocyanin accumulation profiles in the individual cells cultured in all modified media could be approximated to the parts of the normal distribution curves with the constant variance.