Aequorin-based luminescence imaging reveals differential calcium signalling responses to salt and reactive oxygen species in rice roots

Abstract

HighlightBased on the aequorin system, we describe the establishment of a calcium reporter line in rice and test the responses of the reporter towards salt and oxidative stress.

Enlightenment on the aequorin-based platform for screening Arabidopsis stress sensory channels related to calcium signaling

“…To date, only 2 aequorin transgenic rice articles have been reported. 27,32 To investigate the Ca 2C and protein phosphorylation changes induced by microbe/ pathogen-associated molecular patterns (MAMPs/PAMPs), Kurusu et al (2011) established a transgenic rice cell line stably expressing apoaequorin and characterized the interrelationship between MAMP-induced changes in Ca 2C , production of reactive oxygen species (ROS) and protein phosphorylation. 27 Despite the progress achieved by rice culture cells, stable transgenic rice expressing apoaequorin is needed to investigate the changes of Ca 2C in response to various environmental stimuli in rice.…”

“…A recently published article introduced recombinant aequorin into rice and examined the change in Ca 2C in response to salt and ROS stresses. 32 In that paper, the apoaequorin gene was constitutively expressed under control of 35S promoter. The results revealed that the aequorin-based luminescence signal was only observed in roots, but RT-PCR showed that apoaequorin was expressed in all tissues.…”

“…Considering the fact that a Ca 2C spike is the first response to salt stress, 18 and salt-induced ROS accumulation is regulated by Ca 2C , 41 together with the gene expression analysis, a Ca 2C and H 2 O 2 mediated molecular signaling model for the initial response to NaCl in rice roots was proposed. 32…”

Rapid hyperosmotic-induced Ca2+responses inArabidopsis thalianaexhibit sensory potentiation and establish involvement of plastidial KEA transporters

“…Pioneering studies have demonstrated that Arabidopsis seedlings expressing the bioluminescent Ca 2+ reporter protein aequorin exhibit a rapid rise in intracellular Ca 2+ ( [Ca 2+ ]i ) within seconds upon stimulation by NaCl solution (5,6). This rapid osmoticinduced Ca 2+ response has been observed in plant species ranging from rice (7) to the basalbranching moss taxon Physcomitrella patens (8), indicating that this response may be conserved across the Plantae kingdom. Solutions of either NaCl or iso-osmotic mannitol/sorbitol induce nearly identical rapid Ca 2+ responses, indicating that the nature of this rapid stimulus is largely osmotic rather than ionic (5,9,10).…”

A Method for Screening Sensors of Calcium Signaling in Rice

“…However, due to the lack of similar system, no calcium sensors have been reported in rice. Recently, Zhang et al introduced recombinant aequorin into rice (Oryza sativa) and examined the change of Ca 2+ concentration in response to salt and H 2 O 2 stresses [7]. Because typical forward genetic screening is always useful to find genes involved in Ca 2+ signaling, this newly established system can be used to identify novel Ca 2+ -coupled stress sensors or pathways in rice after the establishment of an EMSmutagenized population.…”