Abstract
Different environmental and developmental cues involve low oxygen conditions, particularly those associated to abiotic stress conditions. It is widely accepted that plant responses to low oxygen conditions are mainly regulated by ethylene (ET). However, interaction with other hormonal signaling pathways as gibberellins (GAs), auxin (IAA), or nitric oxide (NO) has been well-documented. In this network of interactions, abscisic acid (ABA) has always been present and regarded to as a negative regulator of the development of morphological adaptations to soil flooding: hyponastic growth, adventitious root emergence, or formation of secondary aerenchyma in different plant species. However, recent evidence points toward a positive role of this plant hormone on the modulation of plant responses to hypoxia and, more importantly, on the ability to recover during the post-hypoxic period. In this work, the involvement of ABA as an emerging regulator of plant responses to low oxygen conditions alone or in interaction with other hormones is reviewed and discussed.
Highlights
The alteration of rainfall regimes caused by climate change will generate extremely arid world regions and others with increased pluviometry that will waterlog populated areas and arable lands
In aerated organs of waterlogged plants, hypoxic conditions induce a reduction of gas exchange parameters and a progressive inhibition of photosynthesis rate (Figure 1A) together with an inhibition of the mitochondrial electron transport chain leading to a reduction in ATP production and a subsequent elevation of reactive oxygen species (ROS) production
To ensure a convenient response to environmental oxygen levels, protein oxygen sensors exist in plants and animals known as hypoxia-responsive transcription factors which stability is directly linked to O2 levels: in the presence of oxygen, these transcription factors are ubiquitinated and rapidly degraded by 26S proteasome
Summary
The alteration of rainfall regimes caused by climate change will generate extremely arid world regions and others with increased pluviometry that will waterlog populated areas and arable lands. Waterlogging is a stress condition that restricts access of plant tissues to CO2 and O2 incurring in hypoxic or anoxic conditions, depending on the degree of oxygen depletion. In aerated organs of waterlogged plants, hypoxic conditions induce a reduction of gas exchange parameters and a progressive inhibition of photosynthesis rate (Figure 1A) together with an inhibition of the mitochondrial electron transport chain leading to a reduction in ATP production and a subsequent elevation of reactive oxygen species (ROS) production. Several plant species from the genera Oryza, Rumex, and Nasturtium have developed flooding survival strategies, which are not normally present in cultivated species, but could be introgressed in crops to maintain yield. Some survival flooding strategies of wild Oryza species such as the formation of aerenchyma are already present in several cultivated rice varieties. As floodwaters recede, plants undergo a reoxygenation period to reach the normal cellular oxygen conditions with a great impact
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
