Physiological and transcriptomic analyses reveal the roles of secondary metabolism in the adaptive responses of Stylosanthes to manganese toxicity

Abstract

Background As a heavy metal, manganese (Mn) can be toxic to plants. Stylo (Stylosanthes) is an important tropical legume that exhibits tolerance to high levels of Mn. However, little is known about the adaptive responses of stylo to Mn toxicity. Thus, this study integrated both physiological and transcriptomic analyses of stylo subjected to Mn toxicity. Results Results showed that excess Mn treatments increased malondialdehyde (MDA) levels in leaves of stylo, resulting in the reduction of leaf chlorophyll concentrations and plant dry weight. In contrast, the activities of enzymes, such as peroxidase (POD), phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO), were significantly increased in stylo leaves upon treatment with increasing Mn levels, particularly Mn levels greater than 400 μM. Transcriptome analysis revealed 2471 up-regulated and 1623 down-regulated genes in stylo leaves subjected to Mn toxicity. Among them, a set of excess Mn up-regulated genes, such as genes encoding PAL, cinnamyl-alcohol dehydrogenases (CADs), chalcone isomerase (CHI), chalcone synthase (CHS) and flavonol synthase (FLS), were enriched in secondary metabolic processes based on gene ontology (GO) analysis. Numerous genes associated with transcription factors (TFs), such as genes belonging to the C2H2 zinc finger transcription factor, WRKY and MYB families, were also regulated by Mn in stylo leaves. Furthermore, the C2H2 and MYB transcription factors were predicted to be involved in the transcriptional regulation of genes that participate in secondary metabolism in stylo during Mn exposure. Interestingly, the activation of secondary metabolism-related genes probably resulted in increased levels of secondary metabolites, including total phenols, flavonoids, tannins and anthocyanidins. Conclusions Taken together, this study reveals the roles of secondary metabolism in the adaptive responses of stylo to Mn toxicity, which is probably regulated by specific transcription factors.

GLIS1, a potential candidate gene affect fat deposition in sheep tail

“…LOC101117953 is a retro-copy of PPP1CC (protein phosphatase PP1-gamma catalytic subunit gamma), which is not expressed in adult tissues as it lacks promoter region, and is thus less likely to be the causative gene for the tail phenotypes [ 8 ]. Previous studies also revealed that PDGFD is a likely causal gene for fat deposition in sheep tail, which promotes proliferation and inhibits differentiation of preadipocyte [ 11 , 31 – 33 ]. Two SNPs in PDGFD significantly affect the tail length and width [ 34 ].…”

“…Previous studies provided evidence of promising candidate genes influencing tail types based on single nucleotide polymorphism (SNP) markers [ 3 , 6 – 8 ]. However, the fat-tailed trait may be a contribution of multiple genes and have a complicated co-regulation mechanism [ 9 – 11 ]. DairyMeade and East Friesian are the two dairy breeds recently introduced to China with large frame, fast growth rate, lean carcass and typical thin tails.…”

Physiological responses and transcriptomic changes reveal the mechanisms underlying adaptation of Stylosanthes guianensis to phosphorus deficiency

“…Experiments were performed in a greenhouse at temperatures of 25 °C to 32 °C under natural sunlight with a photoperiod of about 13 h at the TCGRI, CATAS, Hainan, China (19°30′N, 109°30′E). Seeds were germinated for 3 d, and stylo seedlings were then transferred to a modified Hoagland nutrient solution containing 250 μM KH 2 PO 4 for 14 d as previously described [71]. After that, seedlings were separately transplanted into nutrient solution supplied with 0, 100 and 250 μM KH 2 PO 4 , which were regarded as low (Pi deprivation), moderate and high P supply treatments, respectively.…”

“…Genes with q-value <0.05 and |log 2 (fold change)| ≥1 were assigned as differentially expressed. GO and KEGG enrichment analyses of DEGs were performed as previously described [71,76]. The interaction networks were analyzed by Cytoscape (version 3.8.0).…”

Transcriptome analysis of soybean leaves response to manganese toxicity

“…Using transcriptome analysis, a total of 2670 cadmium toxicity response genes were obtained in soybean roots [25]. A recent transcriptomic analysis in stylo leaves identified a total of 4094 responsive genes involved in Mn toxicity response [26]. However, transcriptome analysis on soybean response to Mn toxicity is rare.…”