Genetics news & views from students enrolled in BIOL 2110 at Stockton University.
Thursday, August 2, 2018
Aphids manipulate their food-Scientists studying niche construction
There are many of
different aphid species. They all feed on plant sap, known as phloem sap. The
nutritional value of the phloem sap is determined by the sugar concentration
and the concentration and composition of amino acids. Previously it was not
known how the quality of plant sap changes in different plant parts after aphid
infestation, how this change in quality influences the development of aphids,
and how, in turn, the aphids can change the composition of the plant sap.
Müller and her team
are the first to confirm that aphid infestation actually does change the
composition of the plant sap depending on which aphid species is infesting
which specific part of the plant. For example, infestation of the stem close to
the bud with a certain aphid species changes the composition of sugar and
organic acids in the sap. In contrast, infestation of the old leaves with
another aphid species increases the concentration of amino acids. And a further
phenomenon can also be ascertained: 'We were able to observe that the aphid
species that developed best on the stem close to the bud and the other species
that proliferated best on the old leaves each specifically increased the
quality of the plant sap of the corresponding plant part,' says Ruth Jakobs, a
research assistant at the Faculty of Biology. Hence, aphids construct their own
niche in such a way that they are able to profit from it. 'We can assume that
aphids behave in a similar way to, for example, beavers that settle in the dams
they have constructed themselves,' says Müller.
gained their findings by placing aphids on different parts of common tansy
plants the stem close to the bud, a young leaf, and an old leaf and determining
the growth of the populations of these insects at these locations. In addition,
the biologists collected the plant sap and analyzed its chemical composition.