Maleic hydrazide is extensively used as a systemic plant growth regulator and as a herbicide. Maleic hydrazide acts as an inhibitor of the synthesis of nucleic acids and proteins[1][2].
Fluorescein hydrazide is a colorimetric probe formed by the reaction of dihydrazine adipate with fluorescein isothiocyanate. Fluorescein hydrazide can be used to label aldehyde and ketone groups[1][2].