Interaction of silicon and cadmium in Brassica juncea and Brassica napus

Abstract

The objective of this study was to determine the effect of silicon (Si) and cadmium (Cd) on root and shoot growth and Cd uptake in two hydroponically cultivated Brassica species (B. juncea (L.) Czern. cv. Vitasso and B. napus L. cv. Atlantic). Both species are potentially usable for phytoextraction. Inhibitory effects of Cd on root elongation were diminished by the impact of Si. Primary roots elongation in the presence of Cd + Si compared with Cd was stronger and the number of lateral roots was lower in B. juncea than in B. napus. Cd content per plant was higher in B. napus roots and shoots compared with B. juncea. Suberin lamellae were formed closer to the root apex in Cd + Si than in Cd treated plants and this effect was stronger in B. napus than in B. juncea. Accelerated maturation of endodermis was associated with reduced Cd uptake. Cd decreased the content of chlorophylls and carotenoids in both species, but Si addition positively influenced the content of photosynthetic pigments which was higher in B. napus than in B. juncea. Si enhanced more substantially translocation of Cd into the shoot of B. napus than of B. juncea. Based on our results B. napus seems to be more suitable for Cd phytoextraction than B. juncea because these plants produce more biomass and accumulate higher amount of Cd. The protective effect of Si on Cd treated Brassica plants could be attributed to more extensive development of suberin lamellae in endodermis.

Mechanisms of silicon-mediated alleviation of heavy metal toxicity in plants: A review

“…Silicon prompted the development of the apoplasmic barrier in the roots of A. marina under Cd stress . Vatehová et al (2012) also reported the Si-mediated more extensive development of suberin lamellae in endodermis closer to the root tips of rapeseed and Indian mustard under Cd stress. Similarly, Greger et al (2011) reported that in the presence of Si þCd treatments, apoplasmic barriers in endodermis were formed closer to the wheat root apex as compared to Cd-stressed wheat roots.…”

Effects of Silicon on Alleviating Arsenic Toxicity in Maize Plants

“…In the presence of Si, Brassica plants showed more accelerated endoderm development, compared with plants grown only in the presence of Cd. This may have led to lower Cd uptake and reduced toxicity due to a suberin lamella formed in the endodermis of plants supplied with Si (Vatehová et al, 2012).…”

Cadmium effects on mineral nutrition of the Cd-hyperaccumulator Pfaffia glomerata

“…The presence of Cd in the growth media may also cause nutritional disturbances directly competing with nutrient uptake and/or altering essential element distributions and other metabolic processes (Göthberg et al 2004;Gussarson et al 1996;Paiva et al 2004;Sarwar et al 2010). Plant responses to Cd contamination are variable and species-specific (Paiva et al 2004;Vatehová et al 2012), and the present study investigated the effects of different Cd doses in nutrient solution on the macro-and micronutrient content of P. glomerata.…”