Changes in the ultrastructure of soybean cultivars in response to manganese supply in solution culture

Abstract

The deleterious effects of Mn stress on many species have been studied, mainly concerning biochemical, physiological and growth parameters of plants. However, there are few studies relating the anatomical and ultrastructural changes in response to manganese (Mn) nutritional disorders, This study examined the leaf ultrastructure of Mn-inefficient (IAC-15, Santa Rosa) and Mn-efficient (IAC-Foscarin 31) soybean (Glycine max L.) genotypes in response to three rates of Mn (0.5, 2 and 200 μmol L -1 ) in the nutrient solution. Symptoms of Mn deficiency developed 12 days after transplanting in IAC-15 and Santa Rosa, followed by IAC-Foscarin 31 on the 15 th day. Only IAC-15 and Santa Rosa leaves showed symptoms of Mn toxicity. The Mn concentration in leaves ranged from 8.6 (deficiency) to 886.3 mg kg -1 d.w. (toxicity). There were no changes either in stomata length or stomata number per unit of leaf surface. Cytoplasm disorganization was observed in IAC-15 under Mn-excess. In this case, the cytoplasm was amorphous, densely stained and extensively disorganized, with increased vacuolation. Mn effects were not found in mitochondria and nucleus in any of the genotypes tested. Under all Mn concentrations, many lipid globules were observed in the IAC-15 chloroplasts. There was an increase in the number of plastids as well as in the size of starch grains within IAC-Foscarin 31 chloroplasts as Mn concentration in the nutrient solution increased. Genotypes had marked differences in the ultrastructure organization, mainly in leaf chloroplasts grown under conditions of both Mn deficiency and toxicity (the most sensitive genotype was IAC-15).

Protective effect of Mn(III)–desferrioxamine B upon oxidative stress caused by ozone and acid rain in the Brazilian soybean cultivar Glycine max “Sambaiba”

“…1). The contents of Mn detected in the present study (60 to 190 mg kg −1 DW) are comparable to those reported by Hannam and Ohki (1988) and Lavras-Junior et al (2010); these Mn contents were established to represent the optimal growth conditions of different soybean cultivars. The dose-response curve of MnDFB showed the highest SOD activity and Mn contents in the leaves of plants treated with 8 μM MnDFB ( Fig.…”

“…The roots and leaves were dried in an oven (70°C), ground, weighed, and digested with a nitric-perchloric acid solution (4:1) at 210°C (Lavras-Junior et al 2010). The solutions were filtered through Millex GV 0.22-μm pore PVDF membranes.…”

Physiological highlights of manganese toxicity symptoms in soybean plants: Mn toxicity responses

“…Excessive concentrations of Mn in plant tissues may alter various processes, such as enzymatic activity, uptake, redistribution, and the use of other nutrients (Ca, Fe, Mg, N and P), in addition to the productive responses of agricultural crops (Lavres Junior et al, 2010). The literature has reported that toxicity by metals e e.g., Mn e induces oxidative stress .…”

EFECTO DEL ENCALAMIENTO EN EL USO EFICIENTE DE MACRONUTRIENTES PARA CACAO (Theobroma cacao L.) EN LA AMAZONIA COLOMBIANA

“…El encalado es una práctica agrícola importante en suelos ácidos para neutralizar la acidez (Castro & Munevar, 2013); en ese sentido, la adición de cal sube el pH, mejora la absorción y redistribución de N en la planta (Lavres et al, 2010) y libera el fósforo retenido en el suelo (Fisher, Yarwood, & James, 2017;Zhu, Li, & Whelan, 2018). Del mismo modo, Rosas, Puentes y Menjivar (2017) encontraron que el incremento de pH mejora la disponibilidad de P en suelos cacaoteros; por otra parte, Baligar y Fageria (2005) demostraron que el encalado mejora la disponibilidad y absorción de nutrientes en plántulas de cacao, indicando que no solo regula la fitotoxicidad sino también el uso eficiente de nutrientes (uen), ya que los suelos ácidos limitan la eficiencia de los fertilizantes, tal y como lo sugieren López, Urbina, Reynoso y Martínez (2018).…”