Ueguchi-Tanada and colleagues discovered the nuclear receptor for this class of molecules that function by degrading DELLA repressor proteins. Their downstream effects include the enhancement of histone H1 kinase activity and expression of mitotic cyclins, consistent with its role in promoting stem elongation. All members of this family are diterpenes derived from an eponymous four-ringed skeleton. They were first identified not in plants but in 
Ueguchi-Tanada and colleagues discovered the nuclear receptor for this class of molecules that function by degrading DELLA repressor proteins. Their downstream effects include the enhancement of histone H1 kinase activity and expression of mitotic cyclins, consistent with its role in promoting stem elongation. All members of this family are diterpenes derived from an eponymous four-ringed skeleton. They were first identified not in plants but in fungi of the genum Fusarium. For 10 points, identify this class of plant hormones which, when over-expressed, cause foolish seedling disease.
Ueguchi-Tanada and colleagues discovered the nuclear receptor for this class of molecules that function by degrading DELLA repressor proteins.
{gibberellins}