Abstract Detail



Ecophysiology

Tuominen, L.K. [1], Reicholf, Rebecca [2], Morcio, Megan [2], Quinones, Arika [2], Litwinowicz, Zachary [2], Peloso, Lucy [2], Moore, Michael [3], Palacio, Sara [4], Drenovsky, Rebecca [2].

Total glucosinolate concentrations in vegetative tissues of gypsum endemic Brassicaceae vary across edaphic conditions and genera.

Gypsum aridlands comprise over 100 million hectares of land globally, yet plant survival on gypsum soils (>60% CaSO4 · 2H2O) has received relatively little scientific attention.  The bulk of work on gypsum endemic plants has focused on Spanish gypsum communities, which include species observed only on gypusm soils (i.e., gypsophiles) and species known to grow both on and off gypsum soils (i.e, gypsovags).  Recent work on New Mexico gypsum endemics has documented parallels in leaf nutrient content to patterns previously observed in Spainish gypsum communities; widespread gypsophiles exhibit high accumulations of leaf Ca and S, while more narrowly distributed gypsophiles and gypsovags tend to exclude excess leaf Ca and S.  Brassicaceous gypsophiles exhibit Ca and S concentrations consistent with this pattern, but unlike other widespread gypsophile lineages, they also contain high leaf N and do not appear to produce endogenous gypsum crystals.  This leaf chemistry is broadly consistent with the accumulation of high concentrations of glucosinolates, specialized metabolites containing both S and N.  To test the hypothesis that gypsum endemic Brassicaceae have adapted to gypsum soils by utilizing glucosinolates as a metabolic S sink, we have collected vegetative tissues from Nerisyrenia and Lepidium congener pairs growing on and off gypsum at sites in New Mexico and Spain for total glucosinolate quantification. Initial results indicate distinct patterns of glucosinolate accumulation between the two genera collected in New Mexico.  In particular, the gypsophile Nerisyrenia linearifolia exhibited greater total glucosinolate concentrations than the gypsovags N. camporum and L. alyssoides, consistent with the glucosinolate adaptation hypothesis.  Unexpectedly, L. alyssoides individuals collected from gypsum soils exhibited significantly lower total glucosinolate concentrations than conspecifics collected off gypsum.  In addition to total glucosinolate quantification for the Spanish gypsophile L. subulatum, we are now carrying out elemental analysis of these vegetative tissues and associated soils to investigate the relative size of glucosinolate pools in the target species and to evaluate the potential role of macronutrient limitation in mediating the present observations.


1 - John Carroll University, Biology Department, 1 John Carroll Blvd, University Heights, Ohio, 44118, United States
2 - John Carroll University, Biology Department, 1 John Carroll Blvd, University Heights, OH, 44118, United States
3 - Oberlin College, Department Of Biology, 119 Woodland St., Science Center K111, Oberlin, OH, 44074, United States
4 - Instituto Pirenaico de Ecología, Departamento de Conservación de la  Biodiversidad y Restauración , Campus de Aula Dei, Avda. Montañana, 1005, Zaragoza, Zaragoza, 50059, España

Keywords:
gypsum
glucosinolates
specialized metabolism
Brassicaceae
Edaphic evolution
sulfur.

Presentation Type: Oral Paper
Number: 0004
Abstract ID:528
Candidate for Awards:None


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