Endoplasmic reticulum-localized CCX2 is required for osmotolerance by regulating ER and cytosolic Ca2+ dynamics in Arabidopsis

Ca2+ signals in plant cells are important for adaptive responsesto environmental stresses. Here, we report that the ArabidopsisCATION/Ca2+ EXCHANGER2 (CCX2), encoding a putative novelcation/Ca2+ exchanger that localizes to the endoplasmic reticulum,is strongly induced by salt and osmotic stresses. Compared withthe wild type, CCX2 loss- and gain-of-function mutants were lessand more tolerant to different osmotic stress, respectively, anddisplayed the most noteworthy phenotypes during salt stress.Remarkably, Cameleon Ca2+ sensors revealed that CCX2 activityimpacts cytosolic and Endoplasmic Reticulum (ER) Ca2+ concentrations.To our knowledge, ccx2 is the first plant mutant with ameasured alteration in ER Ca2+ concentrations. In this study, weidentified CCX2 as a pivotal player in the regulation of ER Ca2+dynamics that heavily impinge on plant growth upon salt stress.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Arabidopsis CCX2 plays a pivotal role in salt stress tolerance by regulating endoplasmic reticulum and cytosolic Ca2+ dynamics

info:eu-repo/semantics/inPres

Modeling the photoperiodic entrainment of the plant circadian clock

The circadian clock is an endogenous 24 hour rhythm that helps organisms anticipate and adapt to daily and seasonal variations in environment, such as the day/night cycle or changing temperatures. The plant clock is a complex network of transcription factors that regulate each other, forming interlocked feedback loops. Most of its components are light-regulated in some way, making the system highly sensitive to changes in light conditions. Here, we explore the mechanisms by which the plant clock adapts to changing day length. We first present some experimental data illustrating the variety of behaviors found in seedlings exposed to external day/night cycles different from 24 h. We then use a mathematical model to characterize the response of the clock to a wide range of external cycle lengths and photoperiods. We show the existence of several domains of periodic entrainment with different ratios between the external cycle length and the period of the clock, and the presence of quasiperiodic and chaotic behaviors outside of the entrainment range. We simulate knockout mutants with impaired clock function and theoretical variants with diminished light sensitivity to highlight the role of a complex network and multiple light inputs in keeping the clock entrained over a wide range of conditions.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Magnesium maintains the length of the circadian period in Arabidopsis

info:eu-repo/semantics/publishe

Delaying surgery for patients with a previous SARS-CoV-2 infection

Not availabl