Bacterial communities in the rhizosphere of Brachiaria decumbens, Panicum maximum and Noccaea caerulescens used for cadmium phytoextraction in an Oxisol (Typic Hapludox)

• Grant number: 18/07190-3
• Support type: Scholarships abroad - Research Internship - Post-doctor
• Effective date (Start): November 01, 2018
• Effective date (End): October 31, 2019
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal researcher: Luís Reynaldo Ferracciú Alleoni
• Grantee: Flávio Henrique Silveira Rabêlo
• Supervisor abroad: Vangronsveld Jaco
• Home Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Research place: Hasselt University, Diepenbeek, Belgium
• Associated to the scholarship: 17/11299-8 - Cadmium bioavailability in an Oxisol (Typic Hapludox) and its relation with the tolerance of Brachiaria decumbens and Panicum maximum using Noccaea caerulescens as model plant, BP.PD

Abstract

Cadmium (Cd) concentrations in the environment have increased during the last decades, resulting in serious socio-environmental problems such as lowering biomass production from plants grown in Cd-contaminated areas and the entry of Cd into the food chain through the intake of contaminated foods, which can lead to numerous health problems. Therefore, it is indispensable to decrease Cd concentrations in the environment. The use of plants able to accumulate significant amounts of Cd, mainly plants that present high biomass production and fast growth, such as the forage grasses, is a promising alternative to treat contaminated environments. We know that the success of phytoremediation strongly depends on the plant microbiome activities, but this factor has been poorly studied in forage grasses used for Cd phytoextraction. Therefore, our objectives in this study will be (i) to identify the bacterial communities in the rhizosphere of two plant species with high biomass production (Brachiaria decumbens Stapf. cv. Basilisk and Panicum maximum Jacq. cv. Massai) and of a Cd hyperaccumulator species [Noccaea caerulescens (J. & C. Presl) F.K. Mey] in Cd-contaminated Oxisol (Typic Hapludox); (ii) to verify if the presence of Cd modifies the composition of the bacterial communities in the rhizosphere of these plants; and (iii) to evaluate if and how the bacterial community associated with a Cd hyperaccumulator plant is different from the bacterial community of high biomass plants. These results will be used together with the results obtained in another study funded by FAPESP (grant no. 2017/11299-8), where N. caerulescens will be used as a model plant, which will make possible to understand if and how the rhizospheric bacterial community can change the bioavailability of Cd in an Oxisol, the tolerance of the plants to Cd and the Cd phytoextraction efficiency. All plants will be exposed (3.6 mg kg-1 soil) and not exposed to Cd in pots containing 8 L of an Oxisol placed in a greenhouse with controlled conditions for summer and winter. Two control treatments (uncultivated soils contaminated with Cd and uncontaminated) will be used for each growing condition (summer and winter) to identify the "original" microbial communities. Plants will be grown during 40 days after the seed germination in each climatic condition. At the end of the study, the rhizosphere soil will be collected to identify the composition of the rhizospheric bacterial communities. Besides the composition of the bacterial communities, we will determine phytochelatins (PCs) concentrations. Although the determination of PCs is not directly involved in this study, we will perform this analysis during the internship due to the difficulty found in Brazil to make it, since this analysis was proposed in the process FAPESP no. 2017/11299-8. Data will be subjected to analysis of variance, and treatments will be compared by Tukey's test. Correlation studies between the analyzed variables will also be performed.

Scientific publications

(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)

RABELO, FLAVIO HENRIQUE SILVEIRA; LAVRES, JOSE; RAMIRES, THIAGO GENTIL; ALLEONI, LUIS REYNALDO FERRACCIU. Diagnosis and recommendation integrated system and nutritional balance index reveal Cd-induced nutritional disorders in Panicum maximum assayed for Cd phytoextraction. BIOREMEDIATION JOURNAL, v. 24, n. 4 NOV 2020. Web of Science Citations: 0.

SILVEIRA RABELO, FLAVIO HENRIQUE; BORGO, LUCELIA; MERLOTI, LUIS FERNANDO; PYLRO, VICTOR SATLER; NAVARRETE, ACACIO APARECIDO; MANO, RODRIGO HIDEKI; THIJS, SOFIE; VANGRONSVELD, JACO; FERRACCIU ALLEONI, LUIS REYNALDO. Effects of winter and summer conditions on Cd fractionation and bioavailability, bacterial communities and Cd phytoextraction potential of Brachiaria decumbens and Panicum maximum grown in a tropical soil. Science of The Total Environment, v. 728, AUG 1 2020. Web of Science Citations: 1.

SILVEIRA RABELO, FLAVIO HENRIQUE; GAZIOLA, SALETE APARECIDA; ROSSI, MONICA LANZONI; SILVEIRA, NEIDIQUELE MARIA; WOJCIK, MALGORZATA; BAJGUZ, ANDRZEJ; PIOTROWSKA-NICZYPORUK, ALICJA; LAVRES, JOSE; LINHARES, FRANCISCO SCAGLIA; AZEVEDO, RICARDO ANTUNES; VANGRONSVELD, JACO; FERRACCIU ALLEONI, LUIS REYNALDO. Unraveling the mechanisms controlling Cd accumulation and Cd-tolerance inBrachiaria decumbensandPanicum maximumunder summer and winter weather conditions. PHYSIOLOGIA PLANTARUM, AUG 2020. Web of Science Citations: 0.