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BolOST1, an ortholog of Open Stomata 1 with alternative splicing products in Brassica oleracea, positively modulates drought responses in plants.
by Wang M., Yuan F., Hao H., Zhang Y., Zhao H., Guo A., et al. (2013)
- a State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Science, Northwest A&F University, Yangling, Shaanxi, China
- b Hybrid Rapeseed Research Center of Shaanxi Province, Yangling, Shaanxi, China
in Biochem. Biophys. Res. Commun. 442, 214–220. doi: 10.1016/j.bbrc.2013.11.032 –
The BolOST1 gene is strongly induced by drought and high-salt stress.
BolOST1 compensates for OST1 in plant drought stress responses.
BolOST1 possesses kinase activity.
BolOST1 interacts with BolABI1 and BolABI5 and phosphorylates ABI5-N.
Open Stomata 1 (OST1), an ABA-activated sucrose non-fermenting 1 (SNF1)-related protein kinase, is critical for plant drought responses.
We investigated the functions of two splicing isoforms of the OST1 ortholog in Brassica oleracea (BolOST1). BolOST1 expression was found to be dramatically induced by drought and high-salt stress, and the ectopic expression of BolOST1 restored the drought-sensitive phenotype of ost1.
Subcellular localization revealed that BolOST1 is localized in both the nucleus and cytoplasm. BolOST1 was also demonstrated to phosphorylate the N-terminal fragment of ABI5 (ABA Insensitive 5, ABI5-N). A firefly luciferase complementation assay revealed that BolOST1 interacts with both BolABI5 and an ABI1 ortholog in B. oleracea (BolABI1).
Overall, these results suggest that BolOST1 is a functional SnRK2-type protein kinase and that the early ABA signaling network may be conserved between Arabidopsis and cabbage.