New ABA-Hypersensitive Arabidopsis Mutants Are Affected in Loci Mediating Responses to Water Deficit and Dickeya dadantii Infection

On water deficit, abscisic acid (ABA) induces stomata closure to reduce water loss by transpiration. To identify Arabidopsis thaliana mutants which transpire less on drought, infrared thermal imaging of leaf temperature has been used to screen for suppressors of an ABA-deficient mutant (aba3-1) cold-leaf phenotype. Three novel mutants, called hot ABA-deficiency suppressor (has), have been identified with hot-leaf phenotypes in the absence of the aba3 mutation. The defective genes imparted no apparent modification to ABA production on water deficit, were inherited recessively and enhanced ABA responses indicating that the proteins encoded are negative regulators of ABA signalling. All three mutants showed ABA-hypersensitive stomata closure and inhibition of root elongation with little modification of growth and development in non-stressed conditions. The has2 mutant also exhibited increased germination inhibition by ABA, while ABA-inducible gene expression was not modified on dehydration, indicating the mutated gene affects early ABA-signalling responses that do not modify transcript levels. In contrast, weak ABA-hypersensitivity relative to mutant developmental phenotypes suggests that HAS3 regulates drought responses by both ABA-dependent and independent pathways. has1 mutant phenotypes were only apparent on stress or ABA treatments, and included reduced water loss on rapid dehydration. The HAS1 locus thus has the required characteristics for a targeted approach to improving resistance to water deficit. In contrast to has2, has1 exhibited only minor changes in susceptibility to Dickeya dadantii despite similar ABA-hypersensitivity, indicating that crosstalk between ABA responses to this pathogen and drought stress can occur through more than one point in the signalling pathway

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Crowd-sourcing observations of volcanic eruptions during the 2021 Fagradalsfjall and Cumbre Vieja events

The Fagradalsfjall1 and Cumbre Vieja eruptions were spectacular and, in the case of Cumbre Vieja, highly destructive. Over their course, the eruptions waxed and waned, fed lava flows, caused numerous felt earthquakes and explosions, localized from crack-fed fissure eruptions into discrete vents and cones, formed fountains up to hundreds of meters high and, for Cumbre Vieja, sent buoyant plumes of pyroclasts and gas to high altitudes. Importantly, both eruptions were visited by people from all over the world and broadcasted widely. While those visitors included many volcanologists, the majority were tourists and volcano enthusiasts, and included photographers, videographers, artists, content creators, and drone pilots. Just 5 years ago, the use of drones on volcanoes was the preserve of a few researchers only8. Today, drones are a mainstay of the photographer’s or videographer’s arsenal, whether amateur or professional. Thanks to the rapid increase in quality and availability of high-resolution digital photography equipment, and the increasing quality of smartphone cameras, it is possible for the enthusiastic amateur to capture natural phenomena in unprecedented detail. Here, we compare and contrast the Fagradalsfjall and Cumbre Vieja eruptions through the lens of the content creators who have visited these sites, with the aim of assessing the utility of non-specialist content for scientific purposes