The Interaction of Jasmonic Acid, Sucrose and Light Is Reflected in Photosynthetic Pigment Metabolism in Potatoes Grown in Vitro

We previously demonstrated that sucrose and jasmonic acid (JA) interact duringin photosynthetic in the regulation of development and pigment metab­ olism of the potato (Solanum tuberosum L cv. Sante) grown in vitro. In this study, the research was extended to the effect of light irradiance and quality on sucrose and JA mediated changes. Potato plantlets grown from stem node cul­ ture were grown on a medium supplemented with 30 mM or 90 mM sucrose and 0.1, 1, or 10 pM JA at 55-70 pmol m-2 s_l (Osram Cool White lights) or at 80-100 pmol n r 2 s” 1 (Osram Fluora lights). Higher amounts of chlorophyll were detected in plants grown at lower irradiance while there was no signifi­ cant difference in carotenoid levels. Sucrose and JA both enhanced root growth and inhibited photosynthetic pigment accumulation. Most effective was 1 pM JA at higher sucrose concentrations. In these growth conditions the plantlets were hyperhydric and had the most developed root system. The pres­ ent study demonstrates that the growth of plants in vitro and the photosynthet­ ic pigment metabolism are highly dependent on the interaction of a number of environmental factors such as sucrose and plant growth regulators in the medi­ um, and light irradiance and quality. This result supports our previous findings that the reduction of photosynthetic pigment accumulation in cv. Sante potato plantlets induced by JA could be mainly the consequence of enhanced import of sucrose from the medium.