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1.
J Evol Biol ; 36(1): 280-295, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36196911

RESUMO

Plants often associate with multiple arthropod mutualists. These partners provide important services to their hosts, but multiple interactions can constrain a plant's ability to respond to complex, multivariate selection. Here, we quantified patterns of genetic variance and covariance among rewards for pollination, biotic defence and seed dispersal mutualisms in multiple populations of Turnera ulmifolia to better understand how the genetic architecture of multiple mutualisms might influence their evolution. We phenotyped plants cultivated from 17 Jamaican populations for several mutualism and mating system-related traits. We then fit genetic variance-covariance (G) matrices for the island metapopulation and the five largest individual populations. At the metapopulation level, we observed significant positive genetic correlations among stigma-anther separation, floral nectar production and extrafloral nectar production. These correlations have the potential to significantly constrain or facilitate the evolution of multiple mutualisms in T. ulmifolia and suggest that pollination, seed dispersal and defence mutualisms do not evolve independently. In particular, we found that positive genetic correlations between floral and extrafloral nectar production may help explain their stable coexistence in the face of physiological trade-offs and negative interactions between pollinators and ant bodyguards. Locally, we found only small differences in G among our T. ulmifolia populations, suggesting that geographic variation in G may not shape the evolution of multiple mutualisms.


Assuntos
Néctar de Plantas , Turnera , Animais , Néctar de Plantas/fisiologia , Turnera/fisiologia , Simbiose , Reprodução , Polinização , Plantas , Flores/genética
2.
J Org Chem ; 69(12): 4159-69, 2004 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-15176843

RESUMO

The reaction of dipyrromethanedicarbinols with pyrrole leading to meso-substituted corroles was investigated to determine whether mild acid catalysts [Dy(OTf)(3), Yb(OTf)(3), Sc(OTf)(3), and InCl(3)] known to provide porphyrins from dipyrromethanecarbinol species while suppressing undesired reversibility (resulting in scrambling) are applicable to reactions affording corrole, and to explore the requirements of the oxidation step. We examined a model reaction leading to meso-triphenylcorrole (TPC) to survey the effect of acid catalyst, acid concentration, ratio of pyrrole to dipyrromethanedicarbinol, oxidant, oxidant quantity, and reaction time on the yield of TPC (by UV-vis) in reactions performed at room temperature in CH(2)Cl(2). Key to this survey was a modification of the well-known spectrophotometric method for monitoring reactions leading to porphyrin. The survey revealed that TPC could be prepared via a subset of the mild acid catalysts [Dy(OTf)(3) and Yb(OTf)(3)], and a preparative-scale reaction afforded an isolated yield of TPC of 49%, devoid of porphyrin. Suppression of reversible processes was further demonstrated by the synthesis of three corroles bearing different meso substituents in defined locations in isolated yields ranging from 50% to 80%. The reaction conditions were applicable to a dipyrromethanedicarbinol bearing electron-withdrawing pentafluorophenyl substituents-provided that the reaction time of the condensation step was increased. We identified circumstances under which DDQ can cause severe interference with the detection and isolation of some corroles, we found that the yield and purity of the corrole depend on judicious selection of oxidation conditions, and we assessed the sensitivity toward light of dilute solutions of the corroles prepared in this study.

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