TY - JOUR
T1 - Arbuscular mycorrhizal fungi restore normal growth in a white poplar clone grown on heavy metal-contaminated soil, and this is associated with upregulation of foliar metallothionein and polyamine biosynthetic gene expression
AU - Cicatelli, Angela
AU - Lingua, Guido
AU - Todeschini, Valeria
AU - Biondi, Stefania
AU - Torrigiani, Patrizia
AU - Castiglione, Stefano
N1 - Funding Information:
This work was supported by funds from the Italian Ministry for Education, University and Research (PRIN 2005_2007 055337), the Italian Ministry of Environment, Land and Sea Protection (‘Research and development in biotechnology applied to the protection of the environment’ in collaboration with The People’s Republic of China) to S.C., and from Associazione Ambiente-Territorio-Formazione to G.L. Cinzia Franchin is gratefully acknowledged for performing the northern blot analyses, and Marco Sobrero for assistance with plant growth and management.
PY - 2010/11
Y1 - 2010/11
N2 - Background and Aims: It is increasingly evident that plant tolerance to stress is improved by mycorrhiza. Thus, suitable plant-fungus combinations may also contribute to the success of phytoremediation of heavy metal (HM)-polluted soil. Metallothioneins (MTs) and polyamines (PAs) are implicated in the response to HM stress in several plant species, but whether the response is modulated by arbuscular mycorrhizal fungi (AMF) remains to be clarified. The aim of the present study was to check whether colonization by AMF could modify growth, metal uptake/translocation, and MT and PA gene expression levels in white poplar cuttings grown on HM-contaminated soil, and to compare this with plants grown on non-contaminated soil. Methods: In this greenhouse study, plants of a Populus alba clone were pre-inoculated, or not, with either Glomus mosseae or G. intraradices and then grown in pots containing either soil collected from a multimetal- (Cu and Zn) polluted site or non-polluted soil. The expression of MT and PA biosynthetic genes was analysed in leaves using quantitative reverse transcription-PCR. Free and conjugated foliar PA concentrations were determined in parallel. Results: On polluted soil, AMF restored plant biomass despite higher Cu and Zn accumulation in plant organs, especially roots. Inoculation with the AMF caused an overall induction of PaMT1, PaMT2, PaMT3, PaSPDS1, PaSPDS2 and PaADC gene expression, together with increased free and conjugated PA levels, in plants grown on polluted soil, but not in those grown on non-polluted soil. Conclusions: Mycorrhizal plants of P. alba clone AL35 exhibit increased capacity for stabilization of soil HMs, together with improved growth. Their enhanced stress tolerance may derive from the transcriptional upregulation of several stress-related genes, and the protective role of PAs.
AB - Background and Aims: It is increasingly evident that plant tolerance to stress is improved by mycorrhiza. Thus, suitable plant-fungus combinations may also contribute to the success of phytoremediation of heavy metal (HM)-polluted soil. Metallothioneins (MTs) and polyamines (PAs) are implicated in the response to HM stress in several plant species, but whether the response is modulated by arbuscular mycorrhizal fungi (AMF) remains to be clarified. The aim of the present study was to check whether colonization by AMF could modify growth, metal uptake/translocation, and MT and PA gene expression levels in white poplar cuttings grown on HM-contaminated soil, and to compare this with plants grown on non-contaminated soil. Methods: In this greenhouse study, plants of a Populus alba clone were pre-inoculated, or not, with either Glomus mosseae or G. intraradices and then grown in pots containing either soil collected from a multimetal- (Cu and Zn) polluted site or non-polluted soil. The expression of MT and PA biosynthetic genes was analysed in leaves using quantitative reverse transcription-PCR. Free and conjugated foliar PA concentrations were determined in parallel. Results: On polluted soil, AMF restored plant biomass despite higher Cu and Zn accumulation in plant organs, especially roots. Inoculation with the AMF caused an overall induction of PaMT1, PaMT2, PaMT3, PaSPDS1, PaSPDS2 and PaADC gene expression, together with increased free and conjugated PA levels, in plants grown on polluted soil, but not in those grown on non-polluted soil. Conclusions: Mycorrhizal plants of P. alba clone AL35 exhibit increased capacity for stabilization of soil HMs, together with improved growth. Their enhanced stress tolerance may derive from the transcriptional upregulation of several stress-related genes, and the protective role of PAs.
KW - Arbuscular mycorrhizal fungi
KW - Populus alba
KW - contaminated soil
KW - heavy metals
KW - metallothioneins
KW - polyamines
KW - white poplar
UR - http://www.scopus.com/inward/record.url?scp=78049304050&partnerID=8YFLogxK
U2 - 10.1093/aob/mcq170
DO - 10.1093/aob/mcq170
M3 - Article
SN - 0305-7364
VL - 106
SP - 791
EP - 802
JO - Annals of Botany
JF - Annals of Botany
IS - 5
ER -