Fluorescent biosensors illuminating plant hormone research

Abstract

Phytohormones act as key regulators of plant growth that coordinate developmental and physiological processes across cells, tissues and organs. As such, their levels and distribution are highly dynamic owing to changes in their biosynthesis, transport, modification and degradation that occur over space and time. Fluorescent biosensors represent ideal tools to track these dynamics with high spatiotemporal resolution in a minimally invasive manner. Substantial progress has been made in generating a diverse set of hormone sensors with recent FRET biosensors for visualising hormone concentrations complementing information provided by transcriptional, translational and degron-based reporters. In this review, we provide an update on fluorescent biosensor designs, examine the key properties that constitute an ideal hormone biosensor, discuss the use of these sensors in conjunction with in vivo hormone perturbations and highlight the latest discoveries made using these tools.

Source-To-Sink Transport of Sugar and Its Role in Male Reproductive Development

“…While the overview of the regulatory network is limited, it provides new sights into how environmental signals influence sugar translocation via a series of transcription factors and proteins. In the future, new tools, including single-cell sequencing and hormone reporters, will provide new opportunities to elucidate the linkage of environmental clues, sugar transport and signaling, and male reproductive development [ 112 , 113 ]. The development of gene editing technology and crop breeding technology, such as CRISPR/Cas9 and Haploid-Inducer Mediated Genome Editing, will improve the understanding of the mechanisms and accelerate improvements in crop traits [ 114 , 115 ].…”

Bioimaging tools move plant physiology studies forward

“…Fluorescent protein-based genetically encoded biosensors are increasingly being used to visualize and analyse ion fluxes, signaling components, and metabolites for real-time studies of cellular processes with high spatial and temporal resolution ( Gjetting et al., 2013 ; Hilleary et al., 2018 ; Walia et al., 2018 ; Walia et al., 2021; Waadt et al, 2021 ). Biosensors detecting hormone distribution and signaling have benefited physiology studies of plant development ( Balcerowicz et al., 2021 ; Isoda et al., 2021 ; Figure 1F ). Carolyn Rasmussen and her team modified a sensitive and dynamically responsive auxin signaling reporter based on the DII domain of Arabidopsis INDOLE-3-ACETIC ACID 28 for use in maize ( Mir et al., 2017 ).…”

Engineering a highly sensitive biosensor for abscisic acid in mammalian cells

“…This biosensor translates the interaction between the ABA‐induced conformationally rearranged the Pyrabactin Resistance 1 (PYR1)/PYR1‐Like (PYL)/Regulatory Components of ABA Receptors (RCAR) ABA receptors, and the co‐receptor protein phosphatases 2C (PP2C) (e.g., Abscisic acid Insensitive 1; ABI1) into fluorescence intensity [1,2]. In addition, other ABA‐responsive reporter systems utilizing downstream ABA signalling components, such as the promoter region of ABA‐responsive genes and the ABA‐dependent kinase activity of snf1‐related protein kinase 2 (SnRK2) family members, allowed deciphering ABA signal transduction as well as ABA homeostasis in plants [3–5].…”

“…and the ABA-dependent kinase activity of snf1-related protein kinase 2 (SnRK2) family members, allowed deciphering ABA signal transduction as well as ABA homeostasis in plants [3][4][5].…”