About this Research Topic
This Research Topic addresses the functional interactions between the signaling pathways controlled by two plant hormones: Abscisic Acid (ABA) and Gibberellins (GAs).
Phytohormones play a crucial role throughout plant life cycle, as they control plant development and response to environmental changes. Abscisic acid (ABA) is a 15-C weak acid that was discovered more than 50 years ago as a growth-inhibiting phytohormone. Gibberellins (GAs) are a wide group of tetracyclic diterpenoid compounds that were characterized as phytohormones almost 70 years ago, although they were firstly isolated from a fungus. Both ABA and GAs are involved in multiple plant developmental processes; ABA generally as a growth inhibitor, and GAs as a growth promoter. Indeed, ABA negatively regulates seed germination as well as the transitions from embryonic to vegetative stage and vegetative stage to reproductive stage. ABA also promotes seed desiccation tolerance and dormancy. On the other hand, GAs promote seed germination, hypocotyl and stem elongation, and control flowering time.
ABA plays also a key role in the response to abiotic stress, such as drought, flooding, salinity and cold. Interestingly, there is increasing evidence for a role of GAs in plant response to adverse environmental conditions. This point further strengthens a model in which these two hormones control plant growth under both normal and stressful developmental conditions. Although DELLA proteins are molecular hubs controlling the balance between ABA and GAs, the molecular mechanism underlying the antagonistic cross-talk between ABA and GA signaling pathways is still to be unveiled.
This Research Topic welcomes manuscripts dealing with the following sub-topics:
- ABA and GAs metabolism under normal and adverse environmental conditions
- Light control of ABA and GAs metabolism and signaling
- Cross-talk of ABA and GAs with other phytohormones
- Interplay of ABA ad GAs in response to abiotic stress
- ABA and GAs cross-talk: DELLA proteins and beyond
- New tools to study ABA and GAs biosynthesis in vivo
- ABA and GAs and agricultural improvement
We welcome the submission of the following article types: Original Research, Methods, Technology Report, Review, Mini Review, and Perspectives.
Keywords: Seed dormancy, DELLA proteins, phytohormones, phytochromes, abiotic stress, seedling development, signaling, metabolism