Accumulation and cellular toxicity of aluminum in seedling of Pinus massoniana

Abstract

BackgroundMasson pine (Pinus massoniana) is one of the most important timber species with adaptable, fast growing, versatile advantages in southern China. Despite considerable research efforts, the cellular and molecular mechanisms of A1 toxicity and resistance in P. massoniana are still poorly understood. The effects of Al on uptake and translocation of Al and other minerals, cell division and nucleolus in P. massoniana were investigated.ResultsThe results indicated that Al accumulated mainly in the roots, and small amounts were transported to aboveground organs. In the presence of Al, the contents of Mg and Fe in stems increased and decreased in roots. Accumulation of Mn in the organs was inhibited significantly. Evidence from cellular experiments showed that Al had an inhibitory effect on the root growth at all concentrations (10−5 – 10−2 M) used. Chromosome fragments, chromosome bridges, C-mitosis and chromosome stickiness were induced during mitosis in the root tip cells. Al induced the formation of abnormal microtubule (MT) arrays, consisting of discontinuous wavy MTs or short MT fragments at the cell periphery. MT organization and function of the mitotic spindle and phragmoplast were severely disturbed. The nucleolus did not disaggregate normally and still remained its characteristic structure during metaphase. Nucleolar particles containing argyrophilic proteins were accumulated and leached out from the nucleus to the cytoplasm. Evidence confirmed that these proteins contained nucleophosmin (B23), nucleolin (C23) and fibrillarin. Western immunoblot analysis revealed that the contents of three nucleolar proteins increased significantly.ConclusionBased on the information provided in this article, it is concluded that root tips of plants are the most sensitive organ to environmental stresses and the accumulation of Al ions primarily is in roots of P. massoniana, and small amounts of Al are transported to aboveground. Root apical meristems play a key role in the immediate reaction to stress factors by activating signal cascades to the other plant organs. Al induces a series of the cellular toxic changes concerning with cell division and nucleolus. The data presented above can be also used as valuable and early markers in cellular changes induced by metals for the evaluation of metal contamination.

Cadmium’s Effect on the Organization of Microtubular Cytoskeleton in Root Tips Cells of Salix matsudana Koidz

“…Jiang et al [3] found that MTs of Allium cepa root meristem cells under heavy metal Pb stress changed significantly with increasing Pb concentrations and prolonged treatment times, cortical MT appeared depolymerization, adhesion, compaction, and mitotic spindle arrangement appeared disorder, even leading to chromosome abnormal separation, seriously influencing the cell cycle. Zhang et al [7] studied the effect of aluminium (Al) on masson pine root meristem cell MTs, which was consistent with the research results before [34]. Heavy metals could lead to significant changes in the cytoskeleton, hindering normal cell differentiation and proliferation.…”

“…Chromosome stickiness was considered to be a chromatid-type aberration and was attributed to the effect of environmental pollutants on degredation or depolymerization of chromosomal DNA, on DNA condensation, and on entanglement of intertions between chromosomes [3]. The chromosome aberration might be the effect of Cd on DNA and RNA synthesis [7]. It was well known that MTs play key roles in both nuclear division and mitosis in plants.…”

“…It can easily be absorbed and accumulated in plant roots, and roots are the first organ in which plants contact this element in Cd-polluted soil [2]. The toxicity of Cd is associated with inhibitory interactions between numerous physiological and metabolic processes, such as interference in mitosis [3][4], toxicity to nucleoli structure [5][6][7], and influence on the organization of microtubular cytoskeleton and tubulin assembly/disassembly processes [7]. To prevent an excess of heavy metals in the metabolically active cytoplasm and organelles, the defence mechanisms come into operation, allowing for detoxification of harmful metal levels at the cellular level, including Cd exclusion, binding, and precipitation in the Pol.…”

Feline vaccine‐associated sarcomagenesis: Is there an inflammation‐independent role for aluminium?

“…Therefore, the discrepancy between our results with the CHO A L assay and those of other assays that are best at detecting base level damage, is likely due to aluminium's association with larger, chromosomal‐level alterations. Indeed, it is well‐known that aluminium causes chromosomal aberrations in plants . Similarly aluminium‐associated aberrations have also been observed in grasshopper spermatocytes and in the bone marrow of injected mice .…”

Crescimento Inicial De Espécies Utilizadas Na Arborização Urbana Em Resposta a Adubação E Calagem

“…O Al interfere na divisão celular das células do ápice da raiz principal e nas raízes laterais, aumenta a rigidez da parede celular através da reticulação de pectinas e reduz a replicação de DNA por causar rigidez na dupla hélice (ZHANG et al, 2014). Estudos indicam que o Al pode limitar o crescimento de espécies importantes para a arborização urbana.…”