Pleiotropic effects in transgenic tobacco plants expressing the oryzacystatin I gene

A study was undertaken to evaluate possible phenotypic alterations in transgenic tobacco (Nicotiana tabacum L, cv, Xanthi) plants expressing the oryzacystatin I gene. Morphophysiologic parameters, such as growth rate, biomass, and leaf, flower, and fruit characteristics were analyzed. Transgenic plants overexpressing the cysteine proteinase inhibitor showed increased growth rate and dry weight, earlier flowering, and increased numbers of flowers and seeds, These pleiotropic effects were correlated with expression level of oryzacystatin I in transgenic lines. The results suggest that oryzacystatin I disrupts the normal activity of cysteine proteinases, which are involved in important physiological processes.