@conference{
author = "Pavlović, Jelena and Samardzic, Jelena and Ilic, Petar and Maksimović, Vuk and Kostić, Ljiljana and Stevic, Nenad and Nikolić, Nina and Liang, Yongchao and Nikolic, Miroslav",
year = "2011",
abstract = "Silicon (Si) and iron (Fe) are respectively the second and the forth most abundant
minerals in the earth’s crust. While the essentiality of Fe is discovered at the middle
of the 19th century, Si is still not fully accepted as an essential element for higher
plants. However, Si is the only known element that alleviates multiple stresses in
plants (e.g. metal excess, drought, salt, lodging, diseases and pests). Fe deficiency
chlorosis is a wide-spread nutritional disorder of many crops grown in calcareous and
alkaline soils. The various adaptation mechanisms are involved in Fe acquisition from
rhizosphere by roots of the so-called strategy 1 plants (all dicots and monocot species,
with exception of grasses which belong to strategy 2), i.e. morphological changes (e.g.
lateral roots and enhanced root hair formation in the apical zones) and physiological
changes such as enhanced proton excretion, FeIII reduction by a plasma membrane
reductase and Fe uptake via an inducible FeII transporter (IRT1). These root responses
have been studied and characterized mainly in the nutrient solutions without Si
supply. Therefore, unambiguous information on an interaction between these two
mineral elements is still lacking. We demonstrated for the first time that the
application of Si in nutrient solution experiments also ameliorates Fe deficiency
chlorosis in cucumber, a Si accumulating dicot, which is also commonly used as a
model plant of strategy 1. I will present recent work from our lab in the context of the
effect of Si on both physiological (e.g. FeIII reducing capacity, release of phenolics
and organic acids) and molecular (e.g. expression of FRO2, HA1 and IRT1, the genes
coding FeIII chelate reductase, H+-ATPase and IRT1, respectively) aspects of root
responses to Fe deficiency. In particular, I will focus on the storage and utilization of root apoplastic Fe, root-to-shoot Fe transport and utilization of Fe from the leaf
apoplast. Based on these investigations we propose the possible role of Si in Fe
deficiency stress as 1) increasing apoplastic Fe pool in roots and 2) improving internal
Fe status and thus delaying Fe chlorosis, rather than a direct regulatory/signaling
effect of Si on the key Fe deficiency inducible root responses.",
publisher = "ISSAG",
journal = "Proceedings of The 5th International Conference on Silicon in Agriculture, September 13-18, 2011, Beijing, China",
title = "Silicon ameliorates iron deficiency chlorosis in strategy I plants: first evidence and possible mechanism (s)",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_2450"
}
