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URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11847
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Item Revisiting the soybean GmNAC superfamily(Frontiers in Plant Science, 2018-12) Melo, Bruno P.; Fraga, Otto T.; Silva, José Cleydson F.; Ferreira, Dalton O.; Brustolini, Otávio J. B.; Carpinetti, Paola A.; Machado, Joao Paulo B.; Reis, Pedro A. B.; Fontes, Elizabeth P. B.The NAC (NAM, ATAF, and CUC) genes encode transcription factors involved with the control of plant morph-physiology and stress responses. The release of the last soybean (Glycine max) genome assembly (Wm82.a2.v1) raised the possibility that new NAC genes would be present in the soybean genome. Here, we interrogated the last version of the soybean genome against a conserved NAC domain structure. Our analysis identified 32 putative novel NAC genes, updating the superfamily to 180 gene members. We also organized the genes in 15 phylogenetic subfamilies, which showed a perfect correlation among sequence conservation, expression profile, and function of orthologous Arabidopsis thaliana genes and NAC soybean genes. To validate our in silico analyses, we monitored the stress-mediated gene expression profiles of eight new NAC-genes by qRT-PCR and monitored the GmNAC senescence-associated genes by RNA-seq. Among ER stress, osmotic stress and salicylic acid treatment, all the novel tested GmNAC genes responded to at least one type of stress, displaying a complex expression profile under different kinetics and extension of the response. Furthermore, we showed that 40% of the GmNACs were differentially regulated by natural leaf senescence, including eight (8) newly identified GmNACs. The developmental and stress-responsive expression profiles of the novel NAC genes fitted perfectly with their phylogenetic subfamily. Finally, we examined two uncharacterized senescence-associated proteins, GmNAC065 and GmNAC085, and a novel, previously unidentified, NAC protein, GmNAC177, and showed that they are nuclear localized, and except for GmNAC065, they display transactivation activity in yeast. Consistent with a role in leaf senescence, transient expression of GmNAC065 and GmNAC085 induces the appearance of hallmarks of leaf senescence, including chlorophyll loss, leaf yellowing, lipid peroxidation and accumulation of H 2 O 2 . GmNAC177 was clustered to an uncharacterized subfamily but in close proximity to the TIP subfamily. Accordingly, it was rapidly induced by ER stress and by salicylic acid under late kinetic response and promoted cell death in planta. Collectively, our data further substantiated the notion that the GmNAC genes display functional and expression profiles consistent with their phylogenetic relatedness and established a complete framework of the soybean NAC superfamily as a foundation for future analyses.Item Comprehensive analysis of the endoplasmic reticulum stress response in the soybean genome: conserved and plant-specific features(BMC Genomics, 2015-10-14) Silva, Priscila Alves; Silva, José Cleydson F.; Caetano, Hanna DN; Machado, Joao Paulo B.; Mendes, Giselle C.; Reis, Pedro AB; Brustolini, Otavio JB; Dal-Bianco, Maximiller; Fontes, Elizabeth PBDespite the relevance of the eukaryotic endoplasmic reticulum (ER)-stress response as an integrator of multiple stress signals into an adaptive response, knowledge about these ER-mediated cytoprotective pathways in soybean (Glycine max) is lacking. Here, we searched for genes involved in the highly conserved unfolded protein response (UPR) and ER stress-induced plant-specific cell death signaling pathways in the soybean genome. Previously characterized Arabidopsis UPR genes were used as prototypes for the identification of the soybean orthologs and the in silico assembly of the UPR in soybean, using eggNOG v4.0 software. Functional studies were also conducted by analyzing the transcriptional activity of soybean UPR transducers. As a result of this search, we have provided a complete profile of soybean UPR genes with significant predicted protein similarities to A. thaliana UPR-associated proteins. Both arms of the plant UPR were further examined functionally, and evidence is presented that the soybean counterparts are true orthologs of previously characterized UPR transducers in Arabidopsis. The bZIP17/bZI28 orthologs (GmbZIP37 and GmbZIP38) and ZIP60 ortholog (GmbZIP68) from soybean have similar structural organizations as their Arabidopsis counterparts, were induced by ER stress and activated an ERSE- and UPRE-containing BiP promoter. Furthermore, the transcript of the putative substrate of GmIREs, GmbZIP68, harbors a canonical site for IRE1 endonuclease activity and was efficiently spliced under ER stress conditions. In a reverse approach, we also examined the Arabidopsis genome for components of a previously characterized ER stress-induced cell death signaling response in soybean. With the exception of GmERD15, which apparently does not possess an Arabidopsis ortholog, the Arabidopsis genome harbors conserved GmNRP, GmNAC81, GmNAC30 and GmVPE sequences that share significant structural and sequence similarities with their soybean counterparts. These results suggest that the NRP/GmNAC81 + GmNAC30/VPE regulatory circuit may transduce cell death signals in plant species other than soybean. Our in silico analyses, along with current and previous functional data, permitted generation of a comprehensive overview of the ER stress response in soybean as a framework for functional prediction of ER stress signaling components and their possible connections with multiple stress responses.