Calmodulin-binding transcription activator (CAMTA) 6 is a key regulator of Na+ homeostasis and salinity stress responses during early germination

In view of the continuous salinization of arable lands world-wide, there is an urgent need to better understand the mechanisms underlying plant responses to salt stress at different stages of their development. We investigated the role of calmodulin (CaM)-binding transcription activator 6 (CAMTA6) under salinity stress during early germination in Arabidopsis. These analyses suggest that ABA signaling is involved in CAMTA6-dependent salt-responsive gene expression, consistent with the ABA hyper-tolerance phenotype and the lack of HKT1 response to ABA and NaCl in the camta6 mutants. Overall design: In order to study the germination behavior of camta6 mutants in the presence of salt (NaCl), seeds of wild-type (Col-0) and an allele of camta6 mutant (camta6-5) with 0 (control) or 200 mM NaCl.