Physiological responses in roots of the grapevine rootstock 140 Ruggeri subjected to Fe deficiency and Fe-heme nutrition.
Iron (Fe)-heme containing fertilizers can effectively prevent Fe deficiency. This paper aims to investigate root physiological responses after a short period of Fe-heme nutrition and Fe deficiency under two pH conditions (with or without HEPES) in the Fe chlorosis-tolerant grapevine rootstock 140 Ruggeri. Organic acids in root exudates, Fe reduction capacity, both roots and root exudates contributions, together with other physiological parameters associated to plant Fe status were evaluated in plants grown in hydroponics. Analyses of root tips by SEM, and Raman and IR spectra of the precipitates of Fe-heme fertilizers were performed. The physiological responses adopted by the tolerant 140 Ruggeri to the application of Fe-heme indicated an increased Fe reduction capacity of the roots. This is the first report showing oxalic, tartaric, malic and ascorbic as major organic acids in Vitis spp. root exudates. Plants reacted to Fe deficiency condition exuding a higher amount of ascorbic acid in the rhizosphere. The presence of HEPES in the medium favoured the malic acid exudation. The lowest concentration of oxalic acid was found in exudates of plants subjected to Fe-heme and could be associated to a higher accumulation in their root tips visualized by SEM analysis.
Department of Agricultural Sciences, University of Bologna, Viale G. Fanin 44, 40127 Bologna, Italy. Electronic address: sandra.lopez@uam.es.
Sandra
S
López-Rayo
Department of Agricultural Sciences, University of Bologna, Viale G. Fanin 44, 40127 Bologna, Italy. Electronic address: michele.difoggia2@unibo.it.
Michele
M
Di Foggia
Department of Agricultural Sciences, University of Bologna, Viale G. Fanin 44, 40127 Bologna, Italy. Electronic address: erica_rmoreira@hotmail.com.
Erica
E
Rodrigues Moreira
Department of Agricultural Sciences, University of Bologna, Viale G. Fanin 44, 40127 Bologna, Italy. Electronic address: silvia.donnini@unibo.it.
Silvia
S
Donnini
Department of Agricultural Sciences, University of Bologna, Viale G. Fanin 44, 40127 Bologna, Italy. Electronic address: giuseppe.bombai@unibo.it.
Giuseppe
G
Bombai
Department of Agricultural Sciences, University of Bologna, Viale G. Fanin 44, 40127 Bologna, Italy. Electronic address: gianfranco.fillippini@unibo.it.
Gianfranco
G
Filippini
Department of Agricultural Sciences, University of Bologna, Viale G. Fanin 44, 40127 Bologna, Italy. Electronic address: annamaria.pisi@unibo.it.
Annamaria
A
Pisi
Department of Agricultural Sciences, University of Bologna, Viale G. Fanin 44, 40127 Bologna, Italy. Electronic address: adamo.rombola@unibo.it.
Adamo D
AD
Rombolà
D000090463:Iron Deficiencies; D008855:Microscopy, Electron, Scanning / Q000379:methods; D018517:Plant Roots / Q000502:physiology*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000379:methods; D027843:Vitis / Q000502:physiology*
Ascorbic acid; Calcium oxalate; Iron chlorosis; Malic acid; Oxalic acid; Root exudates; Tartaric acid