Abstract
To date, few phenotypes have been described for Arabidopsis 14-3-3 mutants or the phenotypes showing the role of 14-3-3 in plant responding to abiotic stress. Although one member of the 14-3-3 protein family (14-3-3 omicron) was shown to be involved in the proper operation of Fe acquisition mechanisms at physiological and gene expression levels in Arabidopsis thaliana, it remains to be explored whether other members play a role in regulating iron acquisition. To more directly and effectively observe whether members of 14-3-3 non-epsilon group have a function in Fe-deficiency adaptation, three higher order quadruple KOs, kappa/lambda/phi/chi (klpc), kappa/lambda/upsilon/nu(klun), and upsilon/nu/phi/chi (unpc) were generated and studied for physiological analysis in this study. The analysis of iron-utilization efficiency, root phenotyping, and transcriptional level of Fe-responsive genes suggested that the mutant with kl background showed different phenotypes from Wt when plants suffered Fe starved, while these phenotypes were absent in the unpc mutant. Moreover, the absence of the four 14-3-3 isoforms in the klun mutant has a clear impact on the 14-3-3 interactome upon Fe deficiency. Dynamics of 14-3-3-client interactions analysis showed that 27 and 17 proteins differentially interacted with 14-3-3 in Wt and klun roots caused by Fe deficiency, respectively. Many of these Fe responsive proteins have a role in glycolysis, oxidative phosphorylation and TCA cycle, the FoF1-synthase and in the cysteine/methionine synthesis. A clear explanation for the observed phenotypes awaits a more detailed analysis of the functional aspects of 14-3-3 binding to the target proteins identified in this study.
Highlights
To date, few phenotypes have been described for Arabidopsis [-3] mutants or the phenotypes showing the role of [-3] in plant responding to abiotic stress
Members of the [-3] protein family, known as important regulators in osmotic stress and salt stress responses in plants, were found as a key regulators required for the proper operation of Fe acquisition mechanisms at physiological and gene expression levels in Arabidopsis thaliana[9]
Singh et al have demonstrated that a key factor, NON-RESPONSE TO Fe-DEFICIENCY 2 (NRF2)/EARLY FLOWERING 8 (ELF8), controls Fe- deficiency response via GRF11 by the activation of histone H3 lysine 4 trimethylation (H3K4me3) in plant roots[10]
Summary
Few phenotypes have been described for Arabidopsis [-3] mutants or the phenotypes showing the role of [-3] in plant responding to abiotic stress. The epsilon members are found in all organisms and are thought to be involved in basal eukaryotic [-3] functions, while the non-epsilon group may be responsible for organismspecific regulatory aspects[15] Both phosphate (P) and nitrate (N) deprivation cause isoform-specific and organ specific [-3] transcript alterations. Van Kleeff et al conducted a series of growth experiments with higher order Arabidopsis [-3] mutants and showed gene specificity and functional redundancy among non-epsilon group members in primary root elongation under control and abiotic stress conditions[20]. Previous studies have demonstrated that root growth, hormone sensitivity and the activation of a neutral cytosolic invertase, showed both specificity and redundancy amongst [-3] non-epsilon group members, kappa, lambda, phi, chi, upsilon and nu[20]. Compared to [-3] isoforms belonging to the epsilon group, non-epsilon [-3] isoforms were more active in the interaction and activation of H+-ATPase[24]
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.
