Cadmium Hyperaccumulation and Reproductive Traits in Natural Thlaspi caerulescens Populations

Abstract

During the last decade, the metal hyperaccumulating plants have attracted considerable attention because of their potential use in decontamination of heavy metal contaminated soils. However, in most species, little is known regarding the function, the ecological and the evolutionary significances of hyperaccumulation. In our study, we investigated the parameters influencing the Cd concentration in plants as well as the biological implications of Cd hyperaccumulation in nine natural populations of Thlaspi caerulescens. First, we showed that Cd concentration in the plant was positively correlated with plant Zn, Fe, and Cu concentrations. This suggested that the physiological and/or molecular mechanisms for uptake, transport and/or accumulation of these four heavy metals interact with each other. Second, we specified a measure of Cd hyperaccumulation capacity by populations and showed that T. caerulescens plants originating from populations with high Cd hyperaccumulation capacity had better growth, by developing more and bigger leaves, taller stems, and produced more fruits and heavier seeds. These results suggest a tolerance/disposal role of Cd hyperaccumulation in this species.

Cadmium Accumulation by Plants of Brassicaceae Family and Its Connection with Their Primary and Secondary Metabolism

“…Cadmium is usually compartmented in vacuoles. However, interaction and deposition in cell walls have been described (Basic et al 2006). These findings are in agreement with next published data (Ni and Wei 2003).…”

Cadmium tolerance and hyperaccumulation by Thlaspi caerulescens populations grown in hydroponics are related to plant uptake characteristics in the field

“…So, although they did not originate from a metalliferous environment, they behaved similarly to Ganges and Prayon in solution, indicating that tolerance is not only related to initial soil characteristics and confirming that it is a constitutive trait (Schat et al 2000). Our results are also compatible with the findings of Basic et al (2006a), who showed that in similar populations (originating from the same area but not the same populations used in this work) Cd concentrations in shoots measured in the field were correlated with total soil concentrations and Zn, Fe and Cu concentrations in shoots. However, when the variance resulting from the soil concentration was removed, the resulting 'hyperaccumulation capacity' calculated on residuals was positively correlated with plant fitness parameters (number and size of leaves) and reproductive traits (number and weight of seeds), indicating better growth and potential reproduction, and suggesting that Cd hyperaccumulation could be a mechanism for increased Cd tolerance.…”

Phytoremediation of Soil Trace Elements

“…Even though T. caerulescens can hyperaccumulate Cd to more than 1000 mg kg À1 dry shoot biomass when grown on contaminated soils [76,[78][79][80][81][82][83][84], it has a rosette growth pattern and even at harvest after vernalization is seldom over 30 cm tall. It is not an optimal plant for Cd phytoextraction, and A. halleri is even smaller.…”