RACe

The impact of climate change on the uptake of arsenic into rice

01.04.2016 bis 30.03.2019

Rice is the staple food worldwide. Unfortunately, global rice yield is already falling behind population growth.
One reason for the decreased yields is the presence of toxic arsenic (As) in many South(-East) Asian paddy soils,
which is known to decrease rice growth and productivity. The current change in Earth’s climate is causing land loss
due to desertification and inundation, leading to lower (rice) crop yields and thus threatening global food security.
According to the highest emission scenario for greenhouse gases presented in the 5th assessment report of the IPCC,
global annual temperatures could rise by more than 5°C by the year 2100. How increased temperatures and CO2
concentrations affect As uptake into rice, and ultimately the quality and production of rice, is unknown and the
main research question of this proposal. Rice will be grown in fully controlled growth chambers with elevated temperature
and partial pressure of CO2, simulating the climate of the year 2100. Changes in rice growth and grain
yield, along with grain organic and inorganic As quantities, will be determined. Furthermore, the shift in soil biogeochemical
processes (and responding atmosphere) resulting from climate change will be investigated, providing the
basic knowledge underlying observed changes in rice yield and quality. The amount and speciation of As in the
soil, plant, and atmosphere will therefore be quantified. To understand the changes in microbial community impacting
soil biogeochemical processes, the abundance and richness will be assessed with modern pyrosequencing techniques,
and functional microbial guilds of interest (iron and arsenic metabolizing bacteria) will be assessed by
qPCR, pyrosequencing, and clone libraries. Overall, the knowledge obtained within the MSC-GF action on the impact
of climate change on As uptake by rice will allow a better risk assessment for productivity of rice in the future
and may give ideas for how to prevent a loss in rice yield and quality in a strongly climate impacted future.