Abstract
Buckwheat is known to accumulate methanol-insoluble proanthocyanidin (PAS-Cya) in leaves, seeds and flowers. However, physiological roles of PAS-Cya are not clarified. To investigate them, we compared PAS-Cya accumulation in natural type and mutant buckwheat, which accumulates little amount of PAS-Cya. We used Tartary buckwheat leaves as materials. PAS-Cya was stained using dimethylaminocinnamaldehyde(DMACA). In mutant leaves, it had some disease-like spots, which contained anthocyanins. Mutants accumulated PAS-Cya only in the spots. On the other hand, natural type leaves had no spots, and it accumulated PAS-Cya in the whole parts of leaves. We also investigate PAS-Cya accumulation in longitudinal section of leaves. In mutant, PAS-Cya was accumulated only in the palisade and spongy layer of spots. On the other hand, natural type contained PAS-Cya in whole parts of epidermis, palisade and spongy layer. These results indicate that PAS-Cya accumulation has important relation to spots generation and inhibition of its magnification.
