Study of Cerrado native species as a resource for the overcoming of aluminum toxicity in agriculture

• Grant number: 12/01351-9
• Support Opportunities: Regular Research Grants
• Duration: June 01, 2012 - May 31, 2014
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Gustavo Habermann
• Grantee: Gustavo Habermann
• Host Institution: Instituto de Biociências (IB). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil
• Associated researchers: Alessandra Ike Coan ; Mary Rosa Rodrigues de Marchi

Abstract

Each year millions of dollars are spent on soil liming for correcting acidity and excessive aluminum (Al3+) contents in agricultural soils of many regions, permitting Brazil to maintain its leadership in agribusiness. Among these regions, the Southeastern region in Brazil was originally occupied by the southern border of the Cerrado vegetation; the agricultural frontiers of Central Brazil were integrally occupied by the Cerrado, and the "present" agricultural frontiers are expanding by the destruction of the Cerrado into the east and north routes. For decades, cerrado species have been neglected and replaced with agriculture; and in the central, north and northwest São Paulo state, and also in the south and southwest Minas Gerais state, the Cerrado vegetation has been replaced with citrus plantations. During those plantings, adaptations of native species to those acid, poor-in-nutrients and rich-in-Al3+ soils were not taken into account. We selected a cerrado species that is considered an Al3+-accumulator (Styrax camporum), and 'Valência' sweet-orange grafted on an Al3+-sensitive (Citrus limonia cv. 'Cravo') and on an Al3+-tolerant (Citrus sunki) rootstock. Under increased Al3+ concentrations (0, 10, 20, 30 e 50 mg L-1) in nutritive solutions, Al3+ will be quantified in different organs, and leaf gas exchange, chlorophyll fluorescence and concentrations of indol-3-acetic acid (IAA) and ethylene (Et) in root tips will be assessed in response to the root environment disturbance caused by Al3+. Our predictions are based on the assumption that Al3+ is an essential nutrient for S. camporum. We hypothesize that the higher the Al3+ concentrations in the nutritive solution the higher the macro- and micro-nutrient and Al3+ contents in plant organs, and the higher the photochemical and gas exchange performances, with significant biomass improvements in S. camporum; but for the citrus species, we predict that Al3+ diminishes such photosynthetic performances, with concomitant biomass reductions. Therefore, we intend to show that Al3+ is allocated into mesophyll cells of the three genotypes. In addition, since Et and IAA are implicated in the Al3+-induced inhibition of root elongation, we also expect that root concentrations of Et will not rise and IAA will not decrease in S. camporum as Al3+ increases in the nutritive solution. On the other hand, under the absence of Al3+ for S. camporum, we expect to find low root concentration of IAA, which would, then, suggest an unbalance in biosynthesis and/or transport of IAA in root cells. In a green-house, we will collect plant material and make measurements every 30 days, for 150 days. A randomized block (boxes with 5 plants) experimental design will be used. Plant growth, absorption rates of Al3+, macro- and micro-nutrients, photosynthetic parameters, as well as hormonal relations in the root of the three genotypes will be assessed. A two-way ANOVA will be run to test the effects of the Al3+ concentrations (5) and genotypes (3) and their interactions on variables of interest at each evaluation time. The Tukey test (± = 0.05) will be used to conduct post-hoc comparisons between mean results. (AU)

Scientific publications

(5)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BRESSAN, ANNA C. G.; COAN, ALESSANDRA I.; HABERMANN, GUSTAVO. X-ray spectra in SEM and staining with chrome azurol S show Al deposits in leaf tissues of Al-accumulating and non-accumulating plants from the cerrado. PLANT AND SOIL, v. 404, n. 1-2, p. 293-306, JUL 2016. (12/01351-9)

BANHOS, OTAVIA F. A. A.; CARVALHO, BRENDA M. DE O.; DA VEIGA, EDUARDO B.; BRESSAN, ANNA C. G.; TANAKA, FRANCISCO A. O.; HABERMANN, GUSTAVO. Aluminum-induced decrease in CO2 assimilation in `Rangpur' lime is associated with low stomatal conductance rather than low photochemical performances. Scientia Horticulturae, v. 205, p. 133-140, JUN 23 2016. (12/01351-9)

BANHOS, OTAVIA F. A. A.; DE SOUZA, MARCELO CLARO; HABERMANN, GUSTAVO. High aluminum availability may affect Styrax camporum, an Al non-accumulating species from the Brazilian savanna. THEORETICAL AND EXPERIMENTAL PLANT PHYSIOLOGY, v. 28, n. 3, p. 321-332, SEP 2016. (13/21293-6, 12/01351-9)

HABERMANN, GUSTAVO; BRESSAN-SMITH, RICARDO. Will we have enough to eat in the near future? What the Brazilian Society of Plant Physiology and The Global Plant Council have to do with it?. THEORETICAL AND EXPERIMENTAL PLANT PHYSIOLOGY, v. 25, n. 4, p. 244-250, OCT-DEC 2013. (12/01351-9)

BANHOS, OTAVIA F. A. A.; CARVALHO, BRENDA M. DE O.; DA VEIGA, EDUARDO B.; BRESSAN, ANNA C. G.; TANAKA, FRANCISCO A. O.; HABERMANN, GUSTAVO. Aluminum-induced decrease in CO2 assimilation in 'Rangpur' lime is associated with low stomatal conductance rather than low photochemical performances. Scientia Horticulturae, v. 205, p. 8-pg., 2016-06-23. (12/01351-9)