As a zinc finger protein gene, SRZ1 (stress repressive zinc finger protein 1) was cloned from rice.
- SRZ1 encodes a protein with three C2C2-type zinc finger motifs that are structurally similar to human ZNF265 zinc fingermotifs.
- SRZ1 and its relatives in plants may play negative roles in abiotic stress signaling and the down-regulation of them might be crucial for plant tolerance against stresses. SRZ1 might function as a upstream repressor of some abiotic stress-related genes and the repression of these genes might lead to the sensitivity of transgenic plants under abiotic stress.
GO assignment(s): GO:0008270
The transgenic tobacco plants:
- line 3
- line 9
- The seeds of transgenic and wild-type plants were germinated and grown on 1/2 MS medium for 14 d and then transferred onto 1/2 MS medium (without sucrose) supplied with 200 mM NaCl for 5 d.
- For cold stress, the 14 d old transgenic or wild-type seedlings were transferred to soil and grew for 2 weeks. After the seedlings were subjected to cold treatment (4 8C) for 24 h, most of transgenic plants were wilted while wild-type plants grew normally. *Thus, expression of SRZ1 in tobacco increases plant sensitivity to cold and salt stresses.
- SRZ1 was expressed with high level in leaves and markedly repressed by salt, cold, drought and abcisic acid stresses but not by salicylic acid and blast inoculation in rice seedlings. Ectopic expression of SRZ1 in tobacco plants repressed expression of abiotic stress-related genes including osmotin, NtERB10B, NtERB10C, and increased plant sensitivity to cold and salt stresses.
- The tissue expression pattern showed that SRZ1 gene was expressed with high level in leaves but low in roots. As to metal ion stresses, SRZ1 expression was specifically repressed by FeCl2 treatment but not by ZnCl2 and CdCl2 treatments under experimental conditions. SRZ1 decreased tolerance to cold and salt stress in tobacco.
Histochemical analysis showed SRZ1-GUS fusion protein was located throughout the cell in roots and leaves of stable transgenic tobacco plants, indicating that SRZ1 was localized in cytoplasm in tobacco cells.
Plant SRZ family might play negative roles in response to abiotic stress and the down-regulation of SRZ genes might be crucial for plant tolerance to stresses. Further studies such as characterizing plant SRZ knock-out mutants will be essential to conclude the precise function of plant SRZ family.
Labs working on this gene
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China
- Huang J, Wang M M, Jiang Y, et al. Stress repressive expression of rice SRZ1 and characterization of plant SRZ gene family[J]. Plant science, 2008, 174(2): 227-235.