INRA Centre de Bordeaux Aquitaine
71 avenue E. Bourlaux
CS 20032 33882 Villenave d'Ornon cedex
05 57 12 26 55
PhD study in geochemistry and ecotoxicology, INRA, Bordeaux, France
Mater of Natural Science in Cell Biology, Institute of Botany, Chinese Academy of Sciences, Beijing, China (Dissertation: The effect of low sink demand on the photosynthetic efficiency of Vicia faba; Supervisor: Dr. LI Shaohua)
Bachelor of Science in Biological Science, Shanxi University, Taiyuan, China (Dissertation: The analysis of saikosaponin in 16 wild species of Bupleurum chinense DC.; Supervisor: Prof. HAO Jianping)
Recherches et compétences
Cadmium (Cd) contamination of soils is increasingly of global concern due to its toxicity to humans. Cd can be readily taken up by plants, translocated aboveground and accumulated in edible parts, such as cereal grains which account for the major source of human exposure to Cd. Durum wheat (Triticum turgidum L. subsp. durum) is a cereal widely grown and consumed in Europe, but can accumulate Cd in the grain up to levels close to the European regulatory limit. More deeply understanding the drivers of Cd accumulation in cereal grains is a major issue to counter this threat. Therefore, the main goal of my research is to study the allocation of Cd to durum wheat grains and to assess how Cd allocation processes may vary with agricultural practices (including fertilization, varietal choice) and with the level of Cd exposure. The study includes the following parts:
1) Genotypic variation. It is first necessary to assess to what extent the concentration of grain Cd varies among different cultivars of durum wheat and to identify the main processes responsible for this variability.
2) Grain Cd loading. Cd imported into developing grains can originate in the direct uptake of Cd by roots during grain filling period and/or in the remobilization of Cd originally stored in vegetative organs before anthesis. In the field, late nitrogen (N) fertilization is a common used strategy to maximize the grain protein level. It is reasonable to suspect, by considering the case of zinc who shares with Cd on grain allocation pathways, that both the source and the level of Cd in durum wheat grains would be affected by the plant N nutritional status. This part of work aims at quantifying by stable isotope labeling the extent of the contribution of remobilization to the amount of Cd accumulated in durum wheat grain, and assessing how the contribution is affected by the supply of N post-anthesis. In addition, two cultivars showing high and low Cd accumulation abilities were selected to test whether their contributions of Cd remobilization as well as their dependence towards N status are different.
3) Impact of Cd level. High level of Cd exposure is often used in studying the response of plants to Cd. However, the high Cd level may cause toxic effects and can be rarely encountered in agricultural soils. This part of work aims at investigating the impact of levels of Cd exposure at low dose on the pattern of plant Cd partitioning and on the pathways Cd allocated to the grain. The results may help us to identify the limiting step on the way of Cd loading to the grains.
4) Grain Cd mapping. Using optimized milling processes is one approach to minimize the Cd content in food by removing the Cd rich parts of grain. This part of work aims to study the accumulation and spatial distribution of Cd in grains.
Projets en cours
Ecophysiology of cadmium allocation to durum wheat grains
Yan B, Nguyen C, Candaudap F, Pokrovsky OS, Cornu JY (2017) How does the level of nitrate supply post-anthesis affect the loading of Cd in durum wheat grains? Plant and Soil, in preparation.
Perrier F*, Yan B*, Candaudap F, Pokrovsky OS, Gourdain E, Meleard B, Bussière S, Coriou C, Robert T, Nguyen C, Cornu JY (2016) Variability in grain cadmium concentration among durum wheat cultivars: impact of aboveground biomass partitioning. Plant and Soil. 404: 307-320. doi:10.1007/s11104-016-2847-8 [*co-first author]
Yan B, Duan W, Liu GT, Xu HG, Wang LJ, Li SH (2013) Response of Bean (Vicia faba L.) Plants to Low Sink Demand by Measuring the Gas Exchange Rates and Chlorophyll a Fluorescence Kinetics. PLoS ONE. 8(12): e80770. doi:10.1371/journal.pone.0080770
Xu H, Liu G, Liu G, Yan B, Duan W, Wang L, Li S (2014) Comparison of investigation methods of heat injury in grapevine (Vitis) and assessment to heat tolerance in different cultivars and species. BMC Plant Biology. 14: 156. doi:10.1186/1471-2229-14-156
Liu GT, Ma L, Duan W, Wang BC, Li JH, Xu HG, Yan XQ, Yan B, Li SH, Wang LJ (2014) Differential proteomic analysis of grapevine leaves by iTRAQ reveals responses to heat stress and subsequent recovery. BMC Plant Biology. 14:110. doi:10.1186/1471-2229-14-110