Abstract
ABSTRACT Formate is produced, in plants, by various biochemical pathways and it is degraded by Formate Dehydrogenase FDH, in presence of NAD+, into CO2 and NADH. FDH has been proposed as one of the enzymes regulating molybdenum (Mo) and iron (Fe) homeostasis. Here we explored the impact of FDH perturbation on Mo and Fe plant nutritional status and FDH relevance on the plant responses against abiotic stresses, by using in silico and experimental approaches. The characterization of different Arabidopsis thaliana and Nicotiana tabacum FDH transgenic lines suggests that FDH promoter activity is dependent on both Mo and Fe nutritional supply and that FDH overexpression alters Mo concentrations in seeds and Fe concentration in seeds, leaves and stems. Also, FDH overexpression delays the dark-induced senescence whereas the lack of FDH accelerates its progression. FDH is therefore a multifaceted enzyme with impact on Mo and Fe homeostasis and regulation of dark-induced senescence.
Highlights
Iron (Fe) and Molybdenum (Mo) are essential micronutrients for plants; the net of interactions and reciprocal homeostatic controls between Fe and Mo plant nutritional status involve Mo-dependent enzymes, Fe and Mo transport and their intracellular trafficking (Baxter et al 2008b; Baxter 2009; Bittner 2014; Murgia and Vigani 2015; Vigani et al 2017)
The aim of this work is to validate the hypothesis that formate dehydrogenase (FDH) takes part in the modulation of Mo and Fe homeostasis (Vigani et al 2017); such a hypothesis is supported by various evidences among which the opposite behavior displayed by FDH protein levels in C. sativus root mitochondria in plants grown under Mo or Fe deficiency (Vigani et al 2017)
We explored the role of FDH by using Arabidopsis thaliana and Nicotiana tabacum as model plants; in particular, we analysed A. thaliana and N. tabacum FDH transgenic plants at various Mo and Fe nutritional conditions and after exposure to abiotic stresses
Summary
Iron (Fe) and Molybdenum (Mo) are essential micronutrients for plants; the net of interactions and reciprocal homeostatic controls between Fe and Mo plant nutritional status involve Mo-dependent enzymes, Fe and Mo transport and their intracellular trafficking (Baxter et al 2008b; Baxter 2009; Bittner 2014; Murgia and Vigani 2015; Vigani et al 2017). The NAD+-dependent enzyme formate dehydrogenase (FDH) was proposed as one of the key proteins regulating Fe and Mo homeostasis (Vigani et al 2017). FDH is present in bacteria, fungi and plants and catalyses the reversible reaction: NAD+ + HCOOH ↔ NADH + H+ + CO2. The reduction of CO2 to formate catalysed by FDH takes place in some bacteria and it is considered an attractive approach for carbon fixation (Maia et al 2016; Cotton et al 2018). The reduction of CO2 is not favored in normal conditions in plants, as the standard transformed Gibbs energy of the reaction (ΔrG′°, used for biochemical reactions, see Alberty et al 2011) is around +15 kJ mol−1 (Cotton et al 2018) at pH 7.0 and at ionic strength of 0.25 (the physiological total ion concentration) (Alberty et al 2011)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
