摘要：SummaryCrosstalk among ABA, auxin, and ROS plays critical roles in modulating seed germination, root growth, and suberization. However, the underlying molecular mechanisms remain largely elusive. Here, MYB70, a R2R3-MYB transcription factor was shown to be a key component of these processes inArabidopsis thaliana.myb70seeds displayed decreased sensitivity, while MYB70-overexpressingOX70seeds showed increased sensitivity in germination in response to exogenous ABA through MYB70 physical interaction with ABI5 protein, leading to enhanced stabilization of ABI5. Furthermore, MYB70 modulates root system development (RSA) which is associated with increased conjugated IAA content and H2O2/O2⋅−ratio but reduced root suberin deposition, consequently affecting nutrient uptake. In support of these data, MYB70 positively regulates the expression of auxin conjugation-relatedGH3, while negatively peroxidase-encoding and suberin biosynthesis-related genes. Our findings collectively revealed a previously uncharacterized component that modulates ABA and auxin signaling pathways, H2O2/O2⋅−balance, and suberization, consequently regulating RSA and seed germination.Graphical abstractDisplay OmittedHighlights•MYB70 regulates seed germination by enhancing ABA signaling via interaction with ABI5•MYB70 activates the IAA conjugation process by upregulatingGH3genes expression•MYB70 mediates root growth via repression ofPERgenes•MYB70 negatively regulates suberin biosynthesis in rootsBiological sciences; Cell biology; Plant biology; Plant histology; Plant Genetics
