Influence of copper on root growth and morphology of Pinus pinea L. and Pinus pinaster Ait. seedlings

Abstract

We assessed the effects of Cu on root growth and morphology of stone pine (Pinus pinea L.) and maritime pine (Pinus pinaster Ait.) seedlings grown in culture solutions supplied with 0.012 (control), 0.1, 1 or 5 micro M CuSO(4). The presence of 5 micro M Cu in the nutrient solution completely inhibited root growth of both species within 3 days. In both species, taproot elongation was reduced in the presence of 1 micro M Cu, although partial growth recovery occurred after 7 days of treatment. The presence of 0.1 micro M Cu in the culture solution slightly enhanced root elongation in P. pinaster, but did not significantly influence root elongation in P. pinea. In both species, root weight per unit length increased in response to Cu exposure, and in P. pinaster, root diameter was significantly increased. The Cu treatments also affected lateral root number and length. In the presence of 1 micro M Cu, both species formed only short lateral primordia. The 1 micro M Cu treatment increased the lateral root index (number of roots per cm of root length) of P. pinaster, but decreased that of P. pinea, compared with control values. Neither the 0.1 nor 1 micro M Cu treatment had a significant effect on the mitotic index of either species. We conclude that cell elongation is more sensitive to Cu than cell division. Cell membrane damage, as indicated by Trypan blue staining, occurred after 10 days of exposure to 1 micro M Cu.

Crescimento e qualidade de mudas de<i> Pinus taeda </i>L. submetidas à poda química de raízes.

“…Todavia, com o incremento na dose de sulfato de cobre, houve redução linear no diâmetro do colo (P<0,05), na altura da parte aérea (P<0,05) e na massa seca de raízes secundárias (P<0,001), e efeito quadrático sobre a massa seca de parte aérea (P<0,05) e a massa seca total do sistema radicular (P<0,05) (Tabela 1). Resultados semelhantes foram observados por Arduini et al (1995), testando sulfato de cobre em mudas de Pinus pinaster Ait. e Pinus pinea L. Os autores observaram que a aplicação de 1 mM de sulfato de cobre inibiu a elongação radicular com 3 dias de tratamento e promoveu a formação de raízes secundárias curtas, enquanto a dose de 5 mM de sulfato de cobre inibiu completamente o crescimento das raízes.…”

In vitro effects of copper nanoparticles on plant pathogens, beneficial microbes and crop plants

“…In addition, physiological and metabolic differences could contribute to such susceptibility, in the same way that all those factors could be responsible for specific lack of sensitivity of oomycetes against common antifungals (Pérez-de-Luque et al, 2011). Indeed, heavy metal toxicity (which includes copper) can be due to alteration or blocking of enzymes, inhibition of macromolecule synthesis, or disruption of cellular and organellar membranes (Arduini et al, 1995;Denkhaus & Salnikow, 2002).…”

“…Probably, the excess of copper ions released from the nanoparticles altered the root physiological elongation processes adversely leading to inhibited root growth and thereby affecting shoot development and dry weight. Indeed, inhibition of root growth by the presence of copper has been attributed to interferences with cell elongation (Arduini et al, 1995) and cell division (Jiang et al, 2001) by inducement of chromosomal aberrations, abnormal mitosis, damage to cell wall and plasma membrane integrity. It is discernible from the data presented that an inhibitory effect of CuNPs on the shoot was recorded at higher concentrations only when the roots were severely affected, so probably the effect on the shoot could be due to a low root development and not to a direct copper effect.…”

Response of Vicia faba L. to metal toxicity on mine tailing substrate: Geochemical and morphological changes in leaf and root

“…This phenomenon seems to be associated to increased activity of peroxidase (Liu et al, 2004a, b). This enzyme is able to catalyze lignin synthesis (Arduini et al, 1995) and is induced in higher plants exposed to toxic metals (Prasad, 1996). Roots of V. faba L. also showed high amounts of electron-dense particles of metals on the surface and within the cell walls.…”