The role of the root apoplast in aluminium-induced inhibition of root elongation and in aluminium resistance of plants: a review

Abstract

The binding of Al in the cell wall particularly to the pectic matrix and to the apoplastic face of the plasma membrane in the most Al-sensitive root zone of the root apex thus impairing apoplastic and symplastic cell functions is a major factor leading to Al-induced inhibition of root elongation. Although symplastic lesions of Al toxicity cannot be excluded, the protection of the root apoplast appears to be a prerequisite for Al resistance in both Al-tolerant and Al-accumulating plant species. In many plant species the release of organic acid anions complexing Al, thus protecting the root apoplast from Al binding, is a most important Al resistance mechanism. However, there is increasing physiological, biochemical and, most recently also, molecular evidence showing that the modification of the binding properties of the root apoplast contributes to Al resistance. A further in-depth characterization of the Al-induced apoplastic reaction in the most Al-sensitive zone of the root apex is urgently required, particularly to understand the Al resistance of the most Al-resistant plant species.

Spatial distribution of physiological quality of Arábica coffee seeds to cultivate Catuai

“…Studies involving root length are important in the assessment of seedlings' vigor, and it is an important variable in the study of culture development in various types of soil. The inhibition of root growth is an indication of stress, as observed with high aluminum concentrations , caused by toxicity, its accumulation at the apex of the root (Horst et al, 2010). The fresh mass of aerial part (MFPA) presents the highest spatial continuity (a = 105 m) and its spatial distribution with the highest values is found, mostly, in the regions with the highest aerial part length (CPA), which shows the reliability of the geostatistical method.…”

Aluminum accumulation in two Pfaffia glomerata genotypes and its growth effects

“…Aluminum (Al) is the most abundant metal in the Earth's crust and plants grown in soil environments in which roots that are potentially exposed to high Al concentrations may have their growth hampered (HORST et al, 2010). Since a large part of the world's total land area consists of acid soil, much attention has been paid to Al toxicity and plant resistance mechanisms (KOCHIAN et al, 2004).…”

“…Since a large part of the world's total land area consists of acid soil, much attention has been paid to Al toxicity and plant resistance mechanisms (KOCHIAN et al, 2004). Aluminum toxicity inhibits both cell division and root tip elongation (FORTUNATO & NICOLOSO, 2004;HORST et al, 2010), decreasing the root volume, number of lateral roots and increasing the permeability of plasma membrane (YU et al, 2011), thus hindering plants' water supply and nutrient uptake mechanisms (VITORELLO et al, 2005), however its effects may be plant species dependent. I Fundação Estadual de Pesquisa Agropecuária, Centro de Pesquisa Iwar Beckman, Hulha Negra, RS, Brasil.…”

“…I Fundação Estadual de Pesquisa Agropecuária, Centro de Pesquisa Iwar Beckman, Hulha Negra, RS, Brasil. II , or Al 3+ , is the principal rhizotoxic form in acid soils (HORST et al, 2010). Common responses of Al 3+ toxicity in shoots are related to nutritional and water deficiencies, which results in cellular and ultrastructural changes (PEREIRA et al, 2006).…”

“…Common responses of Al 3+ toxicity in shoots are related to nutritional and water deficiencies, which results in cellular and ultrastructural changes (PEREIRA et al, 2006). Moreover, lower stomatal conductance, decreased photosynthetic activity, chlorosis and necrosis of leaves, total decrease in leaf number and size, and decrease in shoot biomass have been reported (HORST et al, 2010). However, among genotypes or cultivars within the same species there is genetic variability for tolerance to Al 3+ toxicity (TABALDI et al, 2009;SINGH et al, 2011), which has allowed the selection of tolerant and productive genotypes, for the utilization of acid soils in biomass production.…”