Variation in content of dihydromaleimide and its glucoside in pea seedlings as affected by growth and red light

Dihydromaleimide (DHMD) and its O-β-glucoside (G-DHMD) are synthesized after germination of pea (Pisum sativum L., cv. Progress No. 9) seed and increase in content accompanying the growth of the shoot. The free aglycone is mostly localized in the apical region, while the glucoside is distributed in the lower par of the shoot. Neither the cotyledons nor the root contain these compounds. The synthesis of DHMD is promoted by phytochrome action but that of the glucoside is not, although the glucoside accumulate more in red light than in darkness. However, the increase of DHMD is not great enough to explain the red light-induced growth inhibition.