Corrigendum to “Chemotaxonomic investigation of Apocynaceae for retronecine-type pyrrolizidine alkaloids using HPLC-MS/MS” [Phytochemistry 185 (2021) 112662]

Barny, Lea A.; Tasca, Julia A.; Sánchez, Hugo; Smith, Chelsea R.; Koptur, Suzanne; Livshultz, Tatyana; Minbiole, Kevin P. C.

doi:10.1016/j.phytochem.2022.113309

Cited by 1 publication

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While all 10 sequenced PA-producing Apocynaceae species have an intact HSS encoding a VXXXD motif (Appendix S1, Table S2), many species with the same motif do not have evidence of PAs (Barny et al, 2021, 2022). Of 17 Apocyneae (VXXXD) genera tested (Barny, et al 2021), PAs have been found in only two, Anodendron and Amphineurion (Sasaki and Hirata, 1970; Colegate et al, 2016).…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, while we can predict HSS genotype (VXXXD) from PA phenotype with some accuracy in Apocynaceae (and across angiosperms), there is much more ambiguity in predicting phenotype from genotype. Setting aside error in phenotypic classification, see extensive discussion in (Barny et al, 2021, 2022), there are many levels at which this disconnect may occur.…”

Section: Discussionmentioning

confidence: 99%

“…Because distribution of PAs in Apocynaceae is underdetermined (Burzynski et al, 2015; Barny et al, 2021, 2022), Livshultz et al (2018) studied a gene in their biosynthetic pathway to test the defense de-escalation hypothesis. Biosynthesis of PAs begins with homospermidine synthase (HSS).…”

Section: Figmentioning

confidence: 99%

“…They showed a single DHS/HSS duplication in the most recent common ancestor (MRCA) of all PA-producing taxa in Apocynaceae, early in the diversification of the APSA clade, and an ancestral HSS with a VXXXD motif. HSS enzymes in genera known for PAs retain the VXXXD motif with one exception [ Alafia (Nerieae), IXXXD, although the sequenced species tested negative for PAs, and PA-positive Alafia species were not sequenced], while genera not known for PAs either retained the VXXXD motif or evolved IXXXD or IXXXN motifs (Barny et al, 2021, 2022) (Figs. 1, 3).…”

Section: Figmentioning

confidence: 99%

“…Here, we revisit the evolution of HSS -like genes in Apocynaceae with expanded sequencing, functional experiments, phenotypic data (Barny et al, 2021, 2022), and tests for selection to ask if we can substantiate a single ancestral recruitment of HSS to PA biosynthesis followed by multiple independent losses of the PA phenotype (Fig. 1) or if the data better support multiple independent recruitments and multiple independent origins of the PA phenotype (Fig.…”

Section: Figmentioning

confidence: 99%

See 4 more Smart Citations

In defense of Apocynaceae: inference on evolution of pyrrolizidine alkaloids from evolution of an enzyme in their biosynthetic pathway, homospermidine synthase

Smith

Kaltenegger

Teisher

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

If plant defenses experience positive selection when they first evolve, evidence of selection on a gene can place the origin of novel defenses on a phylogeny. Prior research on pyrrolizidine alkaloids (PAs), rare specialized metabolites of Apocynaceae, reconstructed evolution of homospermidine synthase (HSS), an enzyme of PA biosynthesis, to infer a single origin of PAs by showing a single duplication in the MRCA of all known PA-producing species that gave rise to an enzyme with the predicted motif (VXXXD) of a functionally optimized HSS. We follow up by testing the effect of amino acid motif on HSS function, revisiting motif evolution in HSS-like genes, and testing for selection to infer evolution of HSS function. Some evidence supports a single origin of PAs: an IXXXD HSS, similar in function to VXXXD HSS, evolved in the MRCA of all PA-producing species; loss of optimized HSS function occurred multiple times via pseudogenization and perhaps via evolution of an IXXXN motif. Other evidence indicates multiple origins: the VXXXD motif, present in all PA-producing species, evolved two or three times independently; branch-site models suggest that the ancestral IXXXD branch was not under positive selection while some VXXXD branches were; there is no evidence of relaxed selection on putatively impaired HSS-like genes (IXXXN motif); substitutions at sites experiencing positive selection occurred on multiple branches in the HSS-like gene tree, suggesting that HSS function may have been optimized in multiple independent lineages. We discuss how complexity of genotype-phenotype maps confounds inference of phenotypic from genic evolution.

show abstract