Aluminum tolerance measured by root growth and mucilage protection in Urochloa brizantha and Urochloa decumbens

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 AlCl3 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.

[1]  M. Iquebal,et al.  Selection of pigeonpea genotypes for tolerance to aluminium toxicity , 2011 .

[2]  J. Kumar,et al.  A comparative study of screening methods for tolerance to aluminum toxicity in pigeonpea (Cajanus cajan (L.) Millspaugh) , 2011 .

[3]  Yunxia Wang,et al.  The role of the root apoplast in aluminium-induced inhibition of root elongation and in aluminium resistance of plants: a review. , 2010, Annals of botany.

[4]  R. Chen,et al.  The role of root border cells in aluminum resistance of pea (Pisum sativum) grown in mist culture , 2009 .

[5]  Chao-Feng Huang,et al.  A rice mutant sensitive to Al toxicity is defective in the specification of root outer cell layers. , 2009, Plant & cell physiology.

[6]  I. Rao,et al.  Intracellular distribution and binding state of aluminum in root apices of two common bean (Phaseolus vulgaris) genotypes in relation to Al toxicity. , 2009, Physiologia plantarum.

[7]  V. Vitorello,et al.  Recent advances in aluminum toxicity and resistance in higher plants , 2005 .

[8]  Roberto Oscar Pereyra Rossiello,et al.  DIFFERENTIAL ROOT RESPONSES TO ALUMINUM STRESS AMONG BRAZILIAN RICE GENOTYPES , 2002 .

[9]  H. Matsumoto,et al.  Protein and peroxidase changes in various root-cell fractions of two upland rice cultivars differing in Al tolerance , 2001 .

[10]  H. Matsumoto,et al.  Changes in cell-wall properties of wheat (Triticum aestivum) roots during aluminum-induced growth inhibition. , 2001, Physiologia plantarum.

[11]  T. Carter,et al.  Differential aluminum tolerance in soybean: An evaluation of the role of organic acids. , 2001, Physiologia plantarum.

[12]  J. Mayer,et al.  The high level of aluminum resistance in signalgrass is not associated with known mechanisms of external aluminum detoxification in root apices. , 2001, Plant physiology.

[13]  T. Carter,et al.  Aluminum accumulation at nuclei of cells in the root tip. Fluorescence detection using lumogallion and confocal laser scanning microscopy. , 2000, Plant physiology.

[14]  Xiaowen Zhao,et al.  The role of root border cells in plant defense. , 2000, Trends in plant science.

[15]  C. Poschenrieder,et al.  Change in apoplastic aluminum during the initial growth response to aluminum by roots of a tolerant maize variety , 1999, Plant physiology.

[16]  Mayandi Sivaguru,et al.  The Distal Part of the Transition Zone Is the Most Aluminum-Sensitive Apical Root Zone of Maize , 1998 .

[17]  G. Taylor,et al.  Accumulation of Al in Root Mucilage of an Al-Resistant and an Al-Sensitive Cultivar of Wheat , 1996, Plant physiology.

[18]  G. Keller-Grein,et al.  Regional experience with Brachiaria: Tropical America-humid lowlands , 1996 .

[19]  D. Parker,et al.  GEOCHEM‐PC—A Chemical Speciation Program for IBM and Compatible Personal Computers , 1995 .

[20]  Z. Rengel.  Role of calcium in aluminium toxicity , 1992 .

[21]  R. Gonzales,et al.  Aluminum Partitioning in Intact Roots of Aluminum-Tolerant and Aluminum-Sensitive Wheat (Triticum aestivum L.) Cultivars. , 1992, Plant physiology.

[22]  Z. Rengel.  Role of calcium in aluminum toxicity , 1992 .

[23]  D. Parker,et al.  Non‐phytotoxicity of the aluminum sulfate ion, AlSO+4 , 1987 .

[24]  H. Marschner,et al.  Mucilage Protects Root Meristems from Aluminium Injury , 1982 .

[25]  C. Konzak,et al.  Visual Detection of Aluminum Tolerance Levels in Wheat by Hematoxylin Staining of Seedling Roots1 , 1978 .