TITLE:
Evaluation of Drought Stress-Inducible Wsi18 Promoter in Brachypodium distachyon
AUTHORS:
Patrick Langille, Wei Wei, Jim Karagiannis, Tim Xing, Lining Tian
KEYWORDS:
Wsi18 Promoter, Drought Inducible, Brachypodium distachyon, ABA, Mannitol
JOURNAL NAME:
Advances in Bioscience and Biotechnology,
Vol.9 No.11,
November
30,
2018
ABSTRACT: The rice Wsi18 promoter confers drought-inducible
gene expression. This property makes it a useful candidate to drive relevant
genes for developing drought resistant traits for different monocot crops. In this study, we showed that the Bradi2G47700 gene, the closest homologue to rice Wsi18, was upregulated in Brachypodium distachyon plants exposed to ABA and mannitol. Wsi18: uidA transgenic B.
distachyon plants were produced and then subjected to ABA or mannitol treatment. The
expression of uidA in three
transgenic lines (line 10, 18 and 37) was significantly upregulated in plants
exposed to ABA (fold increases of 5.61 ± 0.98,
2.88 ± 0.75 and 9.13 ± 1.96, respectively) compared to the same transgenic plant lines without
treatment. The expression of uidA in
two transgenic lines (lines 18 and 37) also showed upregulation
when treated with mannitol (fold increases of 4.43 ± 1.07 and 8.47 ± 2.90,
respectively) compared to the same transgenic plant lines without mannitol
treatment. Moreover, GUS histochemical assay showed increased Wsi18 promoter activity in the leaves and stems of transgenic lines upon treatment with ABA or mannitol. This is the first report of the
drought inducible rice Wsi18 promoter
being active in B. distachyon which is a model plant for molecular biology
research of various monocot plants. Taken together, the results indicate that
the Wsi18 promoter and its homologue may be explored as a useful tool for drought stress-inducible gene expression in different monocot crops.