Iron Induces Root and Leaf Ferric Chelate Reduction Activity in Grapevine Rootstock 140 Ruggeri

Abstract

<jats:p>Ferric chelate reduction (FCR) activity of roots and leaves was determined in the grapevine rootstock 140 Ruggeri under iron (Fe)-deficient and Fe-sufficient conditions. Micropropagated plants were subjected to 0 or 40 μ<jats:sc>m</jats:sc> Fe(III) EDTA in hydroponic culture. After 10 days of treatments, Fe-deficient plants had a lower level of root FCR activity and chlorophyll content compared with Fe-sufficient plants. Iron supply (20 μ<jats:sc>m</jats:sc>) to Fe-deficient plants caused a rapid increase of root FCR activity (five times higher than initial values) and plants restored leaf chlorophyll content, whereas those not supplied with Fe retained reducing activity at low levels. In Fe-sufficient plants, root FCR activity decreased gradually when Fe was removed from the nutrient solution, reaching the same low levels as the Fe-deficient plants. Iron-sufficient plants displayed constitutively elevated root-reducing capacity for 3 weeks in culture under Fe-sufficient conditions. In Fe-deficient plants, root FCR activity was confined at the apical region of the lateral roots, whereas in Fe-treated plants, activity was detected along almost the whole length of the lateral roots. Root hair development, from the aspect of length and density, proved to be independent of the Fe status of rootstock plants. Leaf FCR activity was measured in mesophyll protoplasts from in vitro-growing Fe-deficient and Fe-sufficient plants. Mesophyll protoplasts reducing activity in Fe-deficient plants appeared to be decreased 43.5% or 40.3%, on a protoplast number or protein basis, respectively, in comparison with that in protoplasts from Fe-sufficient plant leaves. The results suggest that Fe is one of the agents inducing root and leaf FCR activity in grapevine rootstock 140 Ruggeri, altering furthermore its localization pattern in roots.</jats:p>

Changes in physiological activities and root exudation profile of two grapevine rootstocks reveal common and specific strategies for Fe acquisition

“…Furthermore, the literature reports of hydroponics-grown Fe-deficient (1 μM) and Fe-sufficient (20 μM) 140R cuttings displaying enhanced FCR activity under the former conditions 26 . The fact that our results agree with those reported by Siminis et al 27 , who used similar plant material (micropropagated 140R) and grew the plants in the absence of Fe (0 μM), stresses the importance of the presence of at least some Fe for the FCR enzyme to function 33 . Significant differences in the levels of FCR activity emerged between Fe-replete Ramsey and 140R, with the latter variety displaying the higher value (Supplementary Fig.…”

The memory of iron stress in strawberry plants

“…Similar results were also obtained by Venturas et al (2014) that reported lower FCR activity in chlorotic elm species compared to plants that developed in Fe sufficient conditions. Similar behaviour has reported in grapevine and in tomato (Siminis and Stavrakakis, 2008;Zouari et al, 2001). To rationalize the results we hypothesize that the root FCR activity of the cultivar "Diamante" seems to be regulated by Fe itself.…”

Influence of Rootstocks on Nitrogen, Phosphorus and Potassium Content in Petioles of Four Table Grape Varieties

“…Little is known about the specific mechanisms used by grape rootstocks to absorb nutrients. Nikolaou et al (2003) and Smart et al (2005) point out that absorption is related to the increased density of root hairs as a response to the deficiency of a nutrient; or as Siminis and Stavrakakis (2008) report, absorption is related to the increased capacity of the roots to assimilate specific nutrients. In all cases, more study is required to understand the influence of the root system in mineral absorption (Nikolaou et al, 2000).…”