Download The B-box zinc finger family transcription factor, AtDBF1, is a positive

The B-box zinc finger family transcription factor, AtDBF1, is a positive
regulator of abiotic stress tolerance through the ABA biosynthesis-mediated
signaling pathway in Arabidopsis
Ji-Hee Min and Cheol Soo Kim*
Departments of Plant Biotechnology, Chonnam National University, Gwangju 500-757,
South Korea
Functional analysis of a putative novel transcription factor Arabidopsis B-box zinc finger
family transcription factor protein designated AtDBF1, which contains predicted DNAbinding domain, was performed. The precise roles of the B-box zinc finger family
transcription factors in plant stress are poorly understood. Analyses of an AtDBF1 promoter-glucuronidase (GUS) construct revealed substantial gene expression in whole seedling and
expression of AtDBF1was strongly induced by abscisic acid (ABA), salt and osmotic stress
treatments. atdbf1 mutant line was more sensitive to ABA and salt stress in the cotyledon
greening processes. In contrast, AtDBF1-overexpressing plants were more insensitive to ABA
and salt stress than the wild type. Interestingly, in the presence of ABA or salt stress, the
transcript level of ABA biosynthesis and stress-related genes in AtDBF1-overexpressing
plants was slightly higher than that in the wild type, whereas the expression of ABA
biosynthesis genes in atdbf1 was significantly reduced. Thus, AtDBF1 is involved in ABA
and salt stress response through the ABA biosynthesis-mediated signaling pathway. Taken
together, these findings provide compelling evidence that AtDBF1 is an important regulator
for plant tolerance to abiotic stress.
*
Email: [email protected]