Differential Root Responses to Aluminum Stress Among Brazilian Rice Genotypes

Vasconcelos, S. S.; Jacob-Neto, Jorge; Rossiello, Roberto Oscar Pereyra

doi:10.1081/pln-120003388

Cited by 9 publications

(8 citation statements)

References 21 publications

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“…These areas have been disturbed by intense acid deposition for the last decades. Aluminum (Al) toxicity is deemed to be one of the major concerns of low rice productivity in acid upland and lowland acid sulfate soils (International Rice Research Institute (IRRI) 1978; Fageria and Carvalho 1982;Vasconcelos et al 2002), although rice has a higher degree of Al resistance than that of wheat, barley and rye among cereal crops (Foy 1988). The mechanisms for the high Al resistance of rice are not well understood, although genetic variability of some rice cultivars in terms of Al toxicity has been documented (Jan and Pettersson 1989).…”

Section: Introductionmentioning

confidence: 99%

Root phosphate exudation and pH shift in the rhizosphere are not responsible for aluminum resistance in rice

Chen

Shen

2008

Acta Physiol Plant

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A series of hydroponic experiments and an agar culture experiment were carried out to investigate aluminum (Al) accumulation and translocation in two rice (Oryza sativa L.) cultivars (Kasalath and Koshihikari) that differ in Al resistance. Al-resistance mechanisms, including Pi exudation under Al stress and pH shifts in the rhizosphere, were also studied. Al content in rice shoots was 41 mg kg -1 on average and did not differ between the two cultivars, which demonstrated that the rice cultivars were not Al accumulators. The majority of Al (95-97%) accumulated in roots. Al content in roots in the resistant cultivar (Koshihikari) was lower than that in the sensitive cultivar (Kasalath), which indicated that Al-exclusion mechanisms were mainly acting in rice. However, the rate of Pi exudation from the whole root or root tips was very low in both cultivars and was not significantly influenced by Al exposure, and thus seemed not to be the main Alresistance mechanism. On the other hand, experiments with pH-buffered solution and color changes following culture in agar medium containing bromocresol purple revealed that the Al-induced pH increase could not explain the high Al resistance of rice. In addition, the Al content in shoots of Koshihikari was lower after the formation of iron plaque on the root surface, whereas that of Kasalath was not lower. These results suggested that rice roots cell wall components or root surfaces such as iron plaque, rather than pH changes and/or root exudates including organic acids and phosphate, play important roles in Al resistance in rice.

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Section: Introductionmentioning

confidence: 99%

Root phosphate exudation and pH shift in the rhizosphere are not responsible for aluminum resistance in rice

Chen

Shen

2008

Acta Physiol Plant

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“…Alternatively, as shown in Figure 1, TRL of U. decumbens was higher than that of U. brizantha in Al treatment. Also, the slight growth increase for this specie at 160 mM could be evidence of a probable adaptive mechanism to stress, as reported by Vasconcelos et al (2002) The higher TRL in U. decumbens was considered to be due to the greater mean root length and not to root branching (Table 2). It was reported in soybean that the elongation of primary roots was suppressed more slightly by Al 3 ' than that of lateral roots and damage occurred only when the apex was in direct contact with the metal (Silva et al 2000(Silva et al , 2001.…”

Section: Discussionmentioning

confidence: 62%

“…Concerning the length of seminal roots from base to apex, RER of the two Urochloa species was reduced to 50 and 10% of control at 40 and 80 mM Al, respectively (Figure 1). It is reported in Al 3 ' tolerant rice that 40 mM Al 3 ' inhibits 50% RER (Vasconcelos et al 2002). Therefore, the Urochloa species in the present study is considered to be Al 3 ' tolerant.…”

Section: Discussionmentioning

confidence: 98%

“…Despite some uncertainties, the root apex is the region most sensitive to aluminuminduced stress in plants (Sivaguru and Horst 1998;Huang et al 2009). Thus, studies of these mechanisms often address morphology, physiology and biochemistry of the root apex, and root length is one of the most sensitive variables (Vasconcelos et al 2002). Indicator dyes for aluminum in roots are an excellent tool for tolerance studies (Polle et al 1978;Rinco´n and Gonza´les 1992;Ramos et al 2007).…”

Section: Introductionmentioning

confidence: 99%

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Aluminum tolerance measured by root growth and mucilage protection inUrochloa brizanthaandUrochloa decumbens

Ramos¹,

França

Alvim

et al. 2012

Journal of Plant Interactions

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Aluminum toxicity on root systems was analyzed through comparing root growth and evaluating the protective function of mucilage in Urochloa decumbens and Urochloa brizantha. Seedlings were grown in a solution with different concentrations of AlCl 3 and with mucilage removed or present. The root elongation rate, total length, number of roots and presence of aluminum at the root apex were measured. Root development was inhibited by aluminum and the elongation rate was maintained without any difference between the two species. A significant reduction in root length was found in U. brizantha. Aluminum did not influence root branching in either species and accumulated mostly in the rhizosphere of U. brizantha, where the mucilage has less of a protective function. The greatest aluminum tolerance was found in U. decumbens, observed through maintenance of total root system growth from lower to higher aluminum toxicity.

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“…Nos experimentos deste trabalho o comprimento radicular foi considerado o parâmetro mais importante no processo de seleção à tolerância ao alumínio, como também já relatado por Silva (2009). Os níveis de toxidez de alumínio para esta planta encontrados neste trabalho estão de acordo com outras pesquisas (VASCONCELOS et al, 2002a;VASCONCELOS et al, 2002b Lemos et al (2015) e Machado (2015). A aroeira-vermelha é uma planta com relativa importância econômica.…”

Section: Discussionunclassified

Avaliação Do Desenvolvimento De Plântulas De Aroeira (Schinus Terebinthifolius R.) Em Diferentes Concentrações De Alumínio

Mezzavilla¹,

Neto²

2017

Semioses

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Differential Root Responses to Aluminum Stress Among Brazilian Rice Genotypes

Cited by 9 publications

References 21 publications

Root phosphate exudation and pH shift in the rhizosphere are not responsible for aluminum resistance in rice

Root phosphate exudation and pH shift in the rhizosphere are not responsible for aluminum resistance in rice

Aluminum tolerance measured by root growth and mucilage protection inUrochloa brizanthaandUrochloa decumbens

Avaliação Do Desenvolvimento De Plântulas De Aroeira (Schinus Terebinthifolius R.) Em Diferentes Concentrações De Alumínio

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