Strigolactones (SLs) are carotenoid-derived molecules with dual functions as rhizosphere signals and plant hormones. However, knowledge on the physiological processes regulated by SLs, including plant growth and adaptation to abiotic stresses, is still limited. In this study, a comprehensive picture of SL biological roles was obtained by applying an integrative transcriptomics and metabolomics approach to the roots of pea mutants ramosus5 (rms5) and rms1, impaired in the SL biosynthetic genes CAROTENOID CLEAVAGE DIOXYGENASE 7 (CCD7) and CCD8, respectively, with those of their corresponding wild-type (WT) genotype. Gene Ontology (GO) enrichment analysis revealed significant downregulation of genes involved in abiotic and oxidative stress responses, hormonal and cell cycle regulation, DNA maintenance and cell division, as well as structural and metabolic processes in rms mutants. In contrast, genes related to response to phosphate starvation were notably upregulated. Hormonal quantification using LC-MS/MS indicated that the absence of SLs in rms mutants is associated with significantly higher levels of jasmonic acid, and significantly lower levels of abscisic acid. To explore whether CCD7, previously associated in vitro with broad carotenoid substrate specificity, also functions is involved in processes beyond SL biosynthesis, we searched for genes and biological processes that are specifically up- or downregulated in the rms5 mutant relative compared to both rms1 and WT, but and that are not significantly enriched in the rms1 when comparing to WT. SL-independent downregulated processes resulting from CCD7 impairment included plant cell wall organization, cell wall modification, and nucleosome assembly, while the upregulated processes were primarily associated with light-dependent energy production. Overall, our study provides insights on the broad biological role of SLs and suggests that CCD7 activity may influence photosynthetic, chromatin, and cell wall-related processes beyond its canonical function in SL biosynthesis. As a non-mutually exclusive hypothesis, carotenoids cleaved by CCD7, or apocarotenoids originating from their non-enzymatic cleavage, might act as signalling molecules regulating these processes.
TRANSCRIPTOME ANALYSIS OF PEA RAMOSUS MUTANTS REVEALS STRIGOLACTONE- DEPENDENT AND INDEPENDENT PROCESSES ASSOCIATED WITH STRESS ADAPTATION AND PLANT DEVELOPMENT
HAIDER I.;ARCIERI F.;GIUDICE G.;GUERRIERO M.;DELVENTO C.;RICCIARDI L.;PAVAN S.
2025-01-01
Abstract
Strigolactones (SLs) are carotenoid-derived molecules with dual functions as rhizosphere signals and plant hormones. However, knowledge on the physiological processes regulated by SLs, including plant growth and adaptation to abiotic stresses, is still limited. In this study, a comprehensive picture of SL biological roles was obtained by applying an integrative transcriptomics and metabolomics approach to the roots of pea mutants ramosus5 (rms5) and rms1, impaired in the SL biosynthetic genes CAROTENOID CLEAVAGE DIOXYGENASE 7 (CCD7) and CCD8, respectively, with those of their corresponding wild-type (WT) genotype. Gene Ontology (GO) enrichment analysis revealed significant downregulation of genes involved in abiotic and oxidative stress responses, hormonal and cell cycle regulation, DNA maintenance and cell division, as well as structural and metabolic processes in rms mutants. In contrast, genes related to response to phosphate starvation were notably upregulated. Hormonal quantification using LC-MS/MS indicated that the absence of SLs in rms mutants is associated with significantly higher levels of jasmonic acid, and significantly lower levels of abscisic acid. To explore whether CCD7, previously associated in vitro with broad carotenoid substrate specificity, also functions is involved in processes beyond SL biosynthesis, we searched for genes and biological processes that are specifically up- or downregulated in the rms5 mutant relative compared to both rms1 and WT, but and that are not significantly enriched in the rms1 when comparing to WT. SL-independent downregulated processes resulting from CCD7 impairment included plant cell wall organization, cell wall modification, and nucleosome assembly, while the upregulated processes were primarily associated with light-dependent energy production. Overall, our study provides insights on the broad biological role of SLs and suggests that CCD7 activity may influence photosynthetic, chromatin, and cell wall-related processes beyond its canonical function in SL biosynthesis. As a non-mutually exclusive hypothesis, carotenoids cleaved by CCD7, or apocarotenoids originating from their non-enzymatic cleavage, might act as signalling molecules regulating these processes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
