Plants as cold specialists from the ice age

Date:
December 21, 2021
Source:
Heidelberg University
Summary:
Plants of the spoonweed group time-and-again quickly adapted to a
changing climate during the Ice Ages of the last two million years.

Evolutionary biologists and botanists used genomic analyses to study
what factors favor adaptation to extreme climatic conditions. The
evolutionary history of the Brassicaceae family provides insights
into how plants may be able to cope with climate change in the
future.



FULL STORY ==========================================================================
As cold relics in an increasingly warming world, plants of the spoonweed
group time and again quickly adapted to a changing climate during
the Ice Ages of the last two million years. An international team of evolutionary biologists and botanists led by Prof. Dr Marcus Koch of
Heidelberg University used genomic analyses to study what factors favour adaptation to extreme climatic conditions. The evolutionary history of
the Brassicaceae family provides insights into how plants may be able
to cope with climate change in the future.


========================================================================== "With the challenges of increasing global warming, developing a basic understanding of how plants adapted to severe environmental change
is increasingly urgent," stresses Prof. Koch, whose "Biodiversity and
Plant Systematics" working group conducts research at the Centre for
Organismal Studies (COS). In many cases, their evolutionary past also
strongly determines the future adaptability of plants as well as their
ability to develop into new forms and types, he continues. The spoonweed
genus, or Latin Cochlearia, from the Brassicaceae family separated from
its Mediterranean relatives more than ten million years ago. While
their direct descendants specialised in response to drought stress,
the spoonweeds conquered the cold and arctic habitats at the beginning
of the Ice Age 2.5 million years ago.

In controlled lab experiments, the researchers studied cultivated species
from both groups to determine how they repeatedly adapted during the
relatively rapidly alternating cold and warm periods over the last
two million years. A "cold training" indicates that the physiological adaptations to drought and salt stress during their early evolution
later helped the plants develop a high tolerance to cold. Although the researchers expected that both groups would show a pronounced response
to this "cold training," there appeared to be no significant difference
in response to cold stress between the cold specialists of the Arctic
and Alpine regions and the dry specialists or species adapted to salt
water from the Mediterranean.

Furthermore, the newly emerged plants adapted to cold developed separate
gene pools that frequently came into contact with one another in the
cold regions.

Because spoonweeds have hardly any genetic barriers to contact between
species, populations with multiple sets of chromosomes developed that, subsequently, were continually reduced in their size. "Time after time,
these species were then able to occupy cold ecological niches," explains
Marcus Koch.

While the gene pool of the cold specialists from the Arctic expanded,
the European spoonweed population has shrunk since the last Ice Age. Cold habitats in Europe are disappearing in the face of significant global
warming, thus seriously endangering all spoonweed species. Only the Danish spoonweed, with its abundant sets of chromosomes, remains unscathed and
in some cases is even spreading. "It is the only species of spoonweed
that changed its life cycle and flourishes in salt and sand locations. In
some of its ecological features, it resembles its faraway Mediterranean cousins," adds Prof. Koch. For the researchers, the physiological
adaptability of the spoonweeds makes them a promising model system to simultaneously study adaptations to drought, cold, and salt stress.

The research was conducted mainly within the framework of the priority programme "Evolutionary Plant Solutions to Ecological Challenges" (SPP
1529) of the German Research Foundation. The data are available in a
public access database. The results of the research were published in
the journal eLife.

========================================================================== Story Source: Materials provided by Heidelberg_University. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. Eva M Wolf, Emmanuel Gaquerel, Mathias Scharmann, Levi Yant,
Marcus A
Koch. Evolutionary footprints of a cold relic in a rapidly warming
world.

eLife, 2021; 10 DOI: 10.7554/eLife.71572 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/12/211221102747.htm

--- up 2 weeks, 3 days, 7 hours, 13 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)