A tobacco cDNA clone encoding a GATA-1 zinc finger protein homologous to regulators of nitrogen metabolism in fungi

摘要: In higher plants, the expression of nitrate assimilation pathway is highly regulated. Although molecular mechanisms involved in this regulation are currently being elucidated, very little known about trans-acting factors that allow and nitrite reductase genes which code for first enzymes pathway. fungus Neurospora crassa, nit-2, major nitrogen regulatory gene, activates unlinked structural specify nitrogen-catabolic during conditions limitation. The nit-2 gene encodes a protein containing single zinc finger motif defined by C-X2-CX17-C-X2-C sequence. This DNA-binding domain recognizes promoter region N. crassa nitrogen-related fragments derived from tomato nia promoter. observed specificity binding suggests existence NIT2-like homolog plants. PCR cross-hybridization techniques were used to isolate, respectively, partial cDNA Nicotiana plumbaginifolia full-length tabacum. These clones encode (named NTL1 nit-2-like), characterized domain, C-X2-C-X18-C-X2-C amino acids, associated with basic region. acid sequence 60% homologous NIT2 domain. Ntl1 present as unique copy diploid species. characteristics compatible those regulator pathway, namely weak inducibility light.