Physiological responses in roots of the grapevine rootstock 140 Ruggeri subjected to Fe deficiency and Fe-heme nutrition

• Published in: Plant physiology and biochemistry 2015-11, Vol.96, p.171-179
• Main Authors: López-Rayo, Sandra, Di Foggia, Michele, Rodrigues Moreira, Erica, Donnini, Silvia, Bombai, Giuseppe, Filippini, Gianfranco, Pisi, Annamaria, Rombolà, Adamo D.
• Format: Article
• Language: English
• Subjects: Ascorbic acid; Calcium oxalate; Iron - deficiency; Iron chlorosis; Malic acid; Microscopy, Electron, Scanning - methods; Oxalic acid; Plant Roots - physiology; Root exudates; Spectroscopy, Fourier Transform Infrared - methods; Spectrum Analysis, Raman - methods; Tartaric acid; Vitis - physiology
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2015.07.034

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. •Root physiological responses to Fe-heme and Fe deficiency in rootstock 140 Ruggeri are presented.•Analyses of root tips by SEM, and Raman and IR spectra of the precipitates of Fe-heme fertilizers were performed.•Iron heme increased Fe reduction capacity of the roots.•Oxalic, tartaric, malic and ascorbic were major organic acids in root exudates.•Data contribute to understanding the Fe deficiency recovery of grapevine plants under field conditions.