Duplication and functional divergence of a calcium sensor in the Brassicaceae

Abstract

The presence of varied numbers of CALCINEURIN B-LIKE10 (CBL10) calcium sensor genes in species across the Brassicaceae and the demonstrated role of CBL10 in salt tolerance in Arabidopsis thaliana and Eutrema salsugineum provided a unique opportunity to determine if CBL10 function is modified in different species and linked to salt tolerance. Salinity effects on species growth and cross-species complementation were used to determine the extent of conservation and divergence of CBL10 function in four species representing major lineages within the core Brassicaceae (A. thaliana, E. salsugineum, Schrenkiella parvula, and Sisymbrium irio) as well as the first diverging lineage (Aethionema arabicum). Evolutionary and functional analyses indicate that CBL10 duplicated within expanded lineage II of the Brassicaceae and that, while portions of CBL10 function are conserved across the family, there are species-specific variations in CBL10 function. Paralogous CBL10 genes within a species diverged in expression and function probably contributing to the maintenance of the duplicated gene pairs. Orthologous CBL10 genes diverged in function in a species-specific manner, suggesting that functions arose post-speciation. Multiple CBL10 genes and their functional divergence may have expanded calcium-mediated signaling responses and contributed to the ability of certain members of the Brassicaceae to maintain growth in salt-affected soils.

The Genome Sequence of Alpine Megacarpaea delavayi Identifies Species-Specific Whole-Genome Duplication

“…The significantly expanded gene families contained 312 genes, which are mainly involved in “response to light,” “response to salt stress,” “response to water deprivation,” and “calcium-mediated signaling” ( Supplementary Table S6 ). This also agrees with the previous predication that some species from the expanded lineage II of Brassicaceae are salt-tolerant ( Monihan et al, 2020 ).…”

Ca2+talyzing Initial Responses to Environmental Stresses

“…The transient influx of Ca 2+ generates unique [Ca 2+ ] cyt signatures that initiate cellular responses to diverse developmental cues and environmental challenges [2,8,9].Changes in [Ca 2+ ] cyt are initial cellular responses to specific biotic and abiotic stimuli, and the cytosolic Ca 2+ signature is decoded by Ca 2+ -binding/[Ca 2+ ] cyt sensor proteins to induce adaptive responses to a given environmental condition [10,11]. Previously, many studies on plant Ca 2+ signaling extensively focused on the biochemical and physiological functions of Ca 2+binding proteins that are consistent with the evolutionary expansion of Ca 2+ -decoding genes in plant lineages [12,13]. However, the cellular dynamics of Ca 2+ influx in response to a specific environmental cue are beginning to unfold.…”