THE EFFECT OF MALEIC HYDRAZIDE ON SYNTHESIS OF LIGNIN
The effect of maleic hydrazide and several other chemicals on the synthesis of lignin was investigated in oat coleoptile, pea hypocotyl, and tobacco. When measured by ultraviolet light absorption, maleic hydrazide depressed While 1,4-naphthoquinone increased the lignin content in the conducting tissues of oat coleoptile. The lignin content of oat coleoptiles treated with maleic hydrazide in presence of 1,4-naphthoquinone and tyrosine was reduced. Additions of ferulic acid generally overcame the effects of maleic hydrazide; p-benzoquinone was ineffective. Gibberellic acid and 2,4-dichlorophenoxyacetic acid generally promoted the synthesis of lignin. Joint use of these chemicals and maleic hydrazide produced intermediate levels of lignin. The hygroscopicity and filling value of flue-cured tobacco was related to the lignin content of the leaf.