Basic region/leucine zipper (bZIP) transcription factors (TF) regulate
ABA-mediated stress response in plants. However, the functions for most bZIP
members in tomato (Lycopersicon esculenta) remain unknown. Jiangsu Normal
University researchers led by Mingku Zhu and Xiaoqing Meng studied the
function of the tomato TF gene, SlbZIP1, under salt and drought stresses.
Silencing of SlbZIP1 in transgenic tomato plants resulted in reduced
tolerance to salt and drought stresses compared to wild type plants. This
was a result of the reduced expression of multiple ABA synthesis- and signal
transduction-related genes in the transgenics. Furthermore, the
transcription levels of multiple genes encoding defense proteins for plant
response to abiotic and biotic stresses were also downregulated in the
These findings suggest that SlbZIP1 is essential in salt and drought stress
tolerance by regulating an ABA-mediated pathway. The gene may hold potential
applications in the development of salt- and drought-tolerant tomatoes.