Contrasting consequences of plant domestication for the chemical defenses of leaves and seeds in lima bean plants
Por:
Shlichta, J. Gwen, Cuny, Maximilien A. C., Hernandez-Cumplido, Johnattan, Traine, Juan, Benrey, Betty
Publicada:
1 sep 2018
Categoría:
Ecology, evolution, behavior and systematics
Resumen:
Plant domestication is assumed to result in reduced levels of defensive
compounds in crops, because this makes the plants more suitable for
consumption by humans and livestock. We argue that this should mainly be
reflected in the concentrations of defense compounds in the plant parts
that are used for consumption and not necessarily for other parts of
crop plants. We tested this hypothesis for domesticated lima bean
(Phaseolus lunatus), by comparing its chemical defenses against a leaf
herbivore, the beet armyworm (Spodoptera exigua), and a seed predator,
the beetle Zabrotes subfasciatus. For seeds and leaves we determined the
concentrations of cyanogenic glycosides (CNGs) in cultivated varieties
and wild populations and evaluated the preference and performance of the
herbivores when exposed to leaves and seeds from wild and cultivated
plants. Concentrations of CNGs were significantly different between wild
and cultivated plants. In the leaves the concentration of CNGs in the
cultivated varieties were more than double that of the wild leaves. In
contrast, seeds from cultivated plants had up to 20 times lower CNG
concentration compared to seeds from the wild populations. Insect
preference and performance do not parallel the chemical data. Larvae of
S. exigua preferred wild leaves but had higher survival on cultivated
leaves. The beetles, however, strongly preferred seeds from cultivated
plants and females developed more quickly on these seeds. We conclude
that domestication of P. lunatus has altered the concentration of CNGs
in both the seeds and the leaves in opposite directions. This results in
differential effects on the herbivores that attack these two plant
structures. The contrasting effect of domestication on different plant
tissues can be explained by the fact that bean plants have been
specifically selected for human consumption of the seeds.
Tissue-specific effects of plant domestication on plant defenses can be
expected for other crops as well. (C) 2018 Gesellschaft fur Okologie.
Published by Elsevier GmbH. All rights reserved.
Filiaciones:
Shlichta, J. Gwen:
Univ Neuchatel, Inst Biol, Rue Emile Argand 11, CH-2000 Neuchatel, Switzerland
Edmonds Community Coll, Dept Biol, Lynnwood, WA USA
Cuny, Maximilien A. C.:
Univ Neuchatel, Inst Biol, Rue Emile Argand 11, CH-2000 Neuchatel, Switzerland
Hernandez-Cumplido, Johnattan:
Univ Neuchatel, Inst Biol, Rue Emile Argand 11, CH-2000 Neuchatel, Switzerland
Univ Nacl Autonoma Mexico, Fac Ciencias, Dept Ecol & Recursos Nat, Ave Univ 3000, Mexico City 04510, DF, Mexico
Traine, Juan:
Univ Neuchatel, Inst Biol, Rue Emile Argand 11, CH-2000 Neuchatel, Switzerland
Benrey, Betty:
Univ Neuchatel, Inst Biol, Rue Emile Argand 11, CH-2000 Neuchatel, Switzerland
|