Interaction between aluminum toxicity and manganese toxicity in soybean (Glycine max)

Abstract

Aluminum (Al) and manganese (Mn) toxicity are two main constraints to crop production in some acid soils. In the present study, hydroponic experiments were conducted to investigate the phytoxicity caused by the metals Al and Mn in the Al-sensitive soybean (Glycine max) cultivar Jilin62. Results showed that more than 80% of the total cellular Al accumulated in the cell walls of the root tissue. Excessive Mn supply significantly increased the Al level in the root and aggravated Al toxicity, and as the result leading to a stronger inhibition of the root-elongation rate and root-biomass production. No obvious change of Al concentration was detected in root-cell organelles and soluble fractions. Interestingly, Al-induced increase in cell wall pectin content in the root was further enhanced by addition of Mn, which might explain how Mn aggravated Al toxicity. In addition, it was found that high levels of Al significantly alleviated Mn toxicity symptoms like brown spots on the old leaves, crinkle on the young leaves and shoot growth inhibition. This Al reduced Mn toxicity was related to the decrease of Mn content in shoots under combined Al and Mn stress. Lanthanum (La 3+ ), which has similar chemical properties as Al, can also reduce Mn toxicity and Mn accumulation in the plant. Thus, it is speculated that Al exerts an antagonistic effect on Mn uptake, and thus leads to alleviated Mn toxicity.

Identification of aluminum-responsive microRNAs in Medicago truncatula by genome-wide high-throughput sequencing

“…and Mn toxicity. For instance, Yang et al (2009) found that excess Mn can increase the accumulation of Al 3? in soybean roots, and that high Al 3?…”

Interaction of aluminium and drought stress on root growth and crop yield on acid soils

“…Root elongation is also inhibited under water stress, but there are two main differences between Al and drought stress: (i) under drought stress shoot growth is much more affected than root growth (reviewed by , whereas short and medium-term Al excess may strongly reduce root growth without affecting shoot growth (Kochian et al 2004;Yang et al 2009); (ii) Al toxicity reduces cell elongation along the entire elongation zone (Kollmeier et al 2000), whereas under water deficit or osmotic stress cell elongation is inhibited only in the basal and central elongation zones (definition of zones according to Ishikawa and Evans 1993), but maintained toward the root apex (Sharp et al 1988) in the distal and apical elongation zones (Shimazaki et al 2005) (Fig. 1).…”

The effect of chromium and aluminum on growth, root morphology, photosynthetic parameters and transpiration of the two barley cultivars

“…However, in natural soilplant systems, plants often have to face multiple metal stresses, and the interactive effects of two or more elements may be far from additive . Interaction of toxic metals can affect growth, biomass and photosynthesis of plants, such as Al and Cd in barley (Guo et al 2004) and soybean (Shamsi et al 2008), Cd and As in Solanum nigrum (Sun et al 2008), Al and Mn in soybean (Yang et al 2009), and Cd and Cr in Dalbergia sissoo (Shah et al 2008). However, the knowledge about concurrent behavior of Al and Cr is still scarce.…”