Effect of aluminum stress on mineral nutrition in rice cultivars differing in aluminum sensitivity

Abstract

The effects of aluminum (Al) stress on ion concentration and distribution were investigated in four rice cultivars (Aiwu and IKP, Al sensitive; IRAT112 and IR6023, Al resistant). Macro and micronutrient levels in plant tissues were markedly affected by Al and the magnitude of this effect depended on the cultivar group (Al resistance versus Al sensitivity) and on the concentration of Al in the nutrient solution. Al decreased Ca, P, K, Mg and Mn concentrations in shoot and K, Mg and Mn in root. It increased Ca and P in root and caused an increase in shoot and root Al contents. All these effects were observed in both cultivar groups, but were more apparent in Al sensitive ones. In conclusion, the results support the idea that, compared to the Al sensitive cultivars Aiwu and IKP, Al resistance in IRAT112 and IR6023 could be explained by a limited absorption and translocation of Al from root to shoot and could also be explained by a more efficient transport of Ca, P and Mn from root to shoot. These findings showed clearly that more than one mechanism may contribute to Al resistance in rice plants. Key words: mechanism resistance, nutrients allocation, oryza sativaEfeito do alumínio na nutrição mineral de cultivares de arroz diferindo na sensibilidade ao alumínio RESUMO Estudou-se o efeito do estresse causado pelo alumínio (Al) na concentração e distribuição de íons de quatro cultivares de arroz (Aiwu e IKP, sensíveis ao Al; IRAT112 e IR6023, resistentes ao Al) e se concluiu que sua presença afetou os níveis de macro e micronutrientes nos tecidos das plantas enquanto a amplitude desse efeito depende dos grupos das cultivares (Al resistente versus Al sensível) e da concentração de Al na solução nutritiva. A presença do Al diminuiu a concentração de Ca, P, K, Mg e Mn nas folhas, mas a aumentou em K, Mg e Mn nas raízes. O Al causou aumento da concentração de Ca e P nas raízes e aumentou a sua quantidade nas folhas e raízes; esses efeitos foram observados nos dois grupos das cultivares, embora de forma mais marcada nas cultivares sensíveis ao Al. Os resultados reforçam a idéia de que, comparativamente às cultivares sensíveis Aiwu e IKP, a resistência ao Al nas cultivares resistentes IRAT112 e IR6023, pode ser explicada por uma absorção limitada e translocação do Al das raízes para as folhas e, possivelmente, por um transporte mais eficiente de Ca, P e Mn das raízes para as folhas. Os resultados mostram que mais de um mecanismo pode contribuir para a resistência ao Al, em plantas de arroz.Palavras-chave: mecanismo de resistência, alocação de nutrientes, oryza sativa

Aluminum in mineral nutrition of upland rice plants

“…This effect can also be verified by observing the accumulation of P in the root, which decreased with the application of Al 3+ ( Figure 2D), confirming the effect described. These results corroborate Macêdo & Jan (2008), who observed an increase in P content in the roots of four rice cultivars as the Al 3+ doses increased in nutrient solution.…”

“…Therefore, greater attention should be given to these micronutrients when upland rice plants are cultivated in soil with high Al 3+ concentration, as Fageria (2001) cites that these are the micronutrients accumulated in greater quantity by this culture. The observed Mn content in shoot and root ( Figure 10A and C) corroborate Macêdo & Jan (2008), who also observed decrease of Mn with the increase of doses of Al 3+ when dealing with rice cultivars.…”

“…Macêdo & Jan (2008) There was also a decrease in the content and accumulation of Mg in shoot and root ( Figure 5A, B, C and D). Al 3+ interferes negatively in the bases of the soil solution, especially Ca and Mg, decreasing their concentration and consequently their uptake by plants (Sousa et al, 2007).…”

“…However, they can have their growth prevented or diminished when cultivated in soils with Al 3+ (Mendonça et al, 2003;Mendonça et al 2005;Freitas et al, 2006;Guimarães et al, 2006;Macêdo & Jan, 2008), which may limit root growth (Kochian et al, 2004).…”

Responses of mineral nutrient contents and transport in red clover under aluminum stress

“…Al toxicity is associated with severe changes in the root system, which consequently interferes with nutrients uptake, transport, and utilization (Rahman et al, 2018). Al toxicity usually leads to a reduction in the uptake of many nutrients in most plants, such as P, Ca, Mg, K, Zn, and Mn (Macêdo & Jan, 2008; Ribeiro et al, 2013) and inhibits the development of these plants. Nevertheless, the ability to increase the concentrations of macronutrients and micronutrients in the roots and stems is considered to be directly related to Al resistance when Al is present in the soil (Bojórquez et al, 2017; Foy, 1988).…”