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.com
Volume 8, Issue 10 (Suppl)
J Earth Sci Clim Change, an open access
ISSN: 2157-7617
Climate Change 2017
October 19-21, 2017
CLIMATE CHANGE
October 19-21, 2017 | Rome, Italy
4
th
World Conference on
Elevated atmospheric CO
2
benefits rhizosphere microenvironment of black locust seedlings in Cd-
and Pb-contaminated soils by altering plant physiology
Xia Jia
Chang’an University, China
E
levated atmospheric CO
2
and contamination of soil with heavy metals co-occur in natural ecosystems and have important
effects on the soil microenvironment by influencing plant physiology. We examined the response of the black locust
rhizosphere microenvironment to elevated atmospheric CO
2
(700 ppm) in combination with Cd- and Pb-contamination.
Elevated CO
2
led to an increase in organic compounds (total soluble sugars, soluble phenolic acids, free acids, and organic
acids), microbial populations, biomass, and activity, and enzyme activity (urease, dehydrogenase, invertase, and β-glucosidase)
and changes in microbial community in rhizosphere soils under Cd, Pb, or Cd + Pb treatments relative to ambient CO
2
.
Elevated CO
2
also corresponded to an increase in chlorophyll a and b in leaves, total sugars, and starch in leaves and stems of
black locust seedlings under Cd and Pb stress relative to either metal alone, which indicated that changes in the rhizosphere
microenvironment was affected by the response of seedlings physiology. The pH was lower under elevated CO
2
+ Pb + Cd
than under metals, which led to changes in Cd and Pb fractionation between soils and plants. Therefore, the removal of Cd
and Pb in rhizosphere soils and the uptake of Cd and Pb by plants increased under elevated CO
2
. The increased removal of Cd
and Pb in soils and the high rate of Cd and Pb uptake under elevated CO
2
indicated that black locust seedlings can be used
for phytoremediation of contaminated soils under global change scenarios. Furthermore, our study also suggests that elevated
CO
2
alters the distribution of heavy metals in soil and plants and stimulates the uptake of plants, thereby probably affecting
food quality and safety. Overall, elevated CO
2
benefits the soil microenvironment in the rhizosphere of black locust seedlings
in Cd- and Pb-contaminated soils.
Biography
Xia Jia has her expertise in evaluation in the effect of global changes combined with heavy metal-polluted soils on ecosystems. Her research has been in the
general field of interrelationships between plants and rhizosphere microenvironment under global changes combined with heavy metals. The long-term objective
of her study is to have a better understanding of the response mechanism of ecosystems to the combination of global change and metal-contaminated soils, and
eventually apply the knowledge gained in her study to assess the environmental risk of global change combined with heavy metal pollution to ecosystems.
jiaxianavy@163.comXia Jia, J Earth Sci Clim Change 2017, 8:10(Suppl)
DOI: 10.4172/2157-7617-C1-036