The mechanisms suppressing nitrate assimilation in plants under nitrogen-repleted condition are poorly known, but researchers may have made a breakthrough. They have recently studied the transcription of nitrate assimilating genes in a unicellular red alga and found that deletion of the negative domain of transcription factor CmMYB1 or a previously unknown protein CmNDB1 is responsible for alleviation of the transcription of nitrate assimilating genes in nitrogen-repleted condition.