Abstract
Plant CIPKs were specific Ser/Thr protein kinases, which
were activated through interaction with calcineurin B-like protein (CBL)
containing four EF hands for Ca(2+) binding. The CBL/CIPK complexes play an
important role in signal transduction in biotic and abiotic stresses, as well
as developmental processes. Here a Ser/Thr protein kinase gene (defined as
GhCIPK6), which was isolated from RNA-Seq profile during cotton somatic
embryogenesis in our previous research was characterized. The GhCIPK6 gene
contains an ORF of 1296bp that putatively encodes a polypeptide of 431 amino
acids with a predicted molecular mass of 48.46kDa and isoelectric point of
9.12. Sequence alignment analysis confirmed that GhCIPK6 has no intron, and it
was homologous to AtCIPK6. Expression analysis of the GhCIPK6 suggested that
they might function in diverse tissues, including styles and anthers but not
fibers. In addition, expression of the GhCIPK6 gene was induced by salt,
drought and ABA treatments. Overexpression of GhCIPK6 significantly enhances
the tolerance to salt, drought and ABA stresses in transgenic Arabidopsis,
indicating that GhCIPK6 acts as a positive regulator in response to salt and
drought stress, and is supposed to be a potential candidate gene to improve
stress tolerance by genetic manipulation in cotton and other crops.