Harnessing the new emerging imaging technologies to uncover the role of Ca²⁺ signalling in plant nutrient homeostasis

Abstract

Increasing crop yields by using ecofriendly practices is of high priority to tackle problems regarding food security and malnutrition worldwide. A sustainable crop production requires a limited use of fertilizer and the employment of plant varieties with improved ability to acquire nutrients from soil. To reach these goals, the scientific community aims to understand plant nutrients homeostasis by deciphering the nutrient sensing and signalling mechanisms of plants. Several lines of evidence about the involvement of Ca 2+ as the signal of an impaired nutrient availability have been reported. Ca 2+ signalling is a tightly regulated process that requires specific protein toolkits to perceive external stimuli and to induce the specific responses in the plant needed to survive. Here, we summarize both older and recent findings concerning the involvement of Ca 2+ signalling in the homeostasis of nutrients. In this review, we present new emerging technologies, based on the use of genetically encoded Ca 2+ sensors and advanced microscopy, which offer the chance to perform in planta analyses of Ca 2+ dynamics at cellular resolution. The harnessing of these technologies with different genetic backgrounds and subjected to different nutritional stresses will provide important insights to the still little-known mechanisms of nutrient sensing in plants.

Then and now

“…Considerable efforts have been made to develop genetically encoded fluorescent Ca 2+ sensors and to detect them in vivo using microscopy techniques. Vigani and Costa () discuss the particular advantages of different technologies and summarize the large body of evidence on Ca 2+ signalling pathways that underpin nutrient sensing in plants.…”

CamelliA-based simultaneous imaging of Ca2+ dynamics in subcellular compartments

“…As a second messenger, Ca 2+ plays a pivotal role in regulating plant adaptive responses to developmental and environmental signals by forming specific Ca 2+ signatures that occur in spikes, waves, and oscillations with a defined duration, amplitude, frequency, and/or subcellular location ( Dodd et al, 2010 ; Kudla et al, 2018 ; Vigani and Costa, 2019 ; Lamers et al, 2020 ). Ca 2+ signatures are generated by Ca 2+ channels, Ca 2+ pumps, and/or Ca 2+ transporters localized in the plasma membrane (PM) or organellar membranes ( Stael et al, 2012 ; Costa et al, 2018 ; Kudla et al, 2018 ; Pan et al, 2019 ; Hilleary et al, 2020 ; He et al, 2021 ), and are presumably decoded by Ca 2+ sensing proteins, for example calmodulin (CaM), CaM-like proteins, calcium-dependent protein kinases, and calcineurin B-like proteins ( Harmon et al, 2000 ; Cheng et al, 2002 ; Luan et al, 2002 ; Harper et al, 2004 ; McCormack et al, 2005 ; DeFalco et al, 2009 ; Weinl and Kudla, 2009 ; Kudla et al, 2018 ; Tang et al, 2020 ).…”

Geomagnetic Field (GMF)-Dependent Modulation of Iron-Sulfur Interplay in Arabidopsis thaliana

“…Mineral nutrients are essential resources for plant growth and development. Therefore, understanding the mechanisms underlying the ability of plants to efficiently acquire nutrients from the soil and distribute them among the organs represents a scientific priority [ 1 ]. Several environmental factors (abiotic and biotic) affect plant mineral nutrition, and, conversely, maintaining the optimal nutrient status allows the plant to respond efficiently to the surrounding environment.…”