Differential accumulation of aluminum in root tips of soybean seedlings

Abstract

In the present study, we investigated the sites of aluminum (Al) accumulation and its effects on the growth, morphology and nutritional status in root tips of soybean (Glycine max L.) genotype Conquista. The seedlings were exposed to nutrient Clark solution, pH 4.0, with 0 (control) and 100 µM of Al for 24, 48 and 72 h. Our results showed an Al accumulation in the superficial layers of the root tip, such as the root cap cells, epidermis and cortex cells, and internally in the cell walls of the meristematic cells. The Al accumulation in the outer cells prevented the entry of this metal in the inner tissues. However, scanning electron micrographs showed damage in the external micromorphology of the root tips. This damage resulted in cellular disorganization in the root cap and epidermis cells leading to a reduction in Ca and Mg uptake. Despite that, there was no change in root growth. Taken together, our findings suggest that genotype Conquista has a capacity to avoid Al toxicity, probably by Al immobilization in the cell walls and in the external tissues of the root tip.

Metabolic and physiological adjustments of maize leaves in response to aluminum stress

“…The Al concentrations were quantified in root tips (0.5 cm) and shoots (Silva et al 2020). The samples were analyzed in an inductively coupled plasma optical emission spectroscopy (ICP-OES, Perkin-Elmer Optima 3000XL, Maryland, USA).…”

Responses of Neotropical Savannah Plant Species to Abiotic Stresses: A Structural and Functional Overview

“…According to Čiamporová [152], the inhibition of root growth may be due to Al impregnation of root cell walls that promotes unequal expansion and changes in tissue organization. This process occurs in many Al-sensitive plants, while in Al-tolerant species the high Al deposition on the cell wall normally does not inhibit root elongation, as reported for soybean seedlings [153]. Organic acid exudation from the roots has been cited as an important strategy for Al exclusion [150,154], which avoids Al uptake and the associated structural and physiological symptoms.…”

Tolerance Level of Butterfly Pea (Clitoria ternatea L.) to Stress Acidity Through Tissue Culture Technique

“…The higher concentration of Al stress could affect cell division and enlargement, so growth in branches was inhibited. According to Silva et al (2020), aluminum was a type of metal that has toxicity for plants which could adversely affect its biochemical and morphophysiological processes. High concentrations of aluminum in acidic soils caused disturbances in morphophysiological and biochemical processes so that plants experienced inhibition of the development of plant organs.…”