Can silicon partially alleviate micronutrient deficiency in plants? a review

Abstract

Silicon protects plants against various biotic and abiotic stresses, including metal toxicity. Under a high metal concentration, Si can externally decrease metal availability to the plant by its precipitation in the growth media, and Si also affects the metal distribution inside the plant, diminishing the damage. Could Si also protect plants against metal deficiency stress? Recently, the physiological role of Si in relation to micronutrients deficiency symptoms has been assessed in several plant species in hydroponics. In cucumber, Si supply mitigated the symptoms of Fe deficiency, but this effect was not clear under Zn-or Mndeficiency conditions. The main factor controlling this beneficial effect seems to be the Si contribution to the formation of metal deposits in the root and/or leaves apoplast and its role in their following remobilization when required. The enhancement of the content of long-distance transport molecules (such as citrate) due to Si addition should also contribute to the metal transport from root to shoot, which will diminish deficiency symptoms.

Biostimulant activity of silicon in horticulture

“…Monomeric silicic acid is the major form of Si that has been identified in the xylem to date (HernandezApaolaza, 2014). Si translocation rates to the shoot via xylem exhibit strong variations among species (Hernandez-Apaolaza, 2014). Indeed, as reported by Mitani and Ma (2005), the Si concentration in xylem sap of rice was higher by a factor of 20 and 100 in comparison with cucumber and tomato, respectively, despite similar external Si concentrations.…”

“…As reported by Guntzer et al (2012), the highest shoot Si concentrations in dicots have been recorded in some Cucurbitaceae (e.g., cucumber), Fabaceae (e.g., pea), Rosales (e.g., elm), and Asteraceae (e.g., sunflower) plant species. The large differences in shoot Si concentrations among plants has led to their classification into active Si accumulators with a concentration of SiO 2 > 1% in dry weight, passive accumulators with 0.5% < SiO 2 < 1% in dry weight and Si rejective plants (excluders) with SiO 2 < 0.5% dry weight (Currie and Perry, 2007;Guntzer et al, 2012;Hernandez-Apaolaza, 2014). Another classification criterion reported by Carey and Fulweiler (2014) is the ratio of Si to calcium (Ca) in the shoot tissues, which discriminates the plants to active Si accumulators when the Si:Ca ratio > 1, passive accumulators when 0.5 < Si:Ca < 1, and Si excluders when Si:Ca < 0.5.…”

Combined effects of soil silicon and drought stress on host plant chemical and ultrastructural quality for leaf‐chewing and sap‐sucking insects

“…Other studies have also shown that Si improves root and leaf growth under drought stress condition (Adatia & Besford, ; Ahmed, Hassen, Qadeer, & Aslam, ; Guo, Lui, Tian, Zhang, & Wang, ; Hattori et al, ). Because root size, architecture and function enhance water and nutrient uptake, Si fertilization can increase drought tolerance in plants (Chaves et al, ; Ehdaie, Layne, & Waines, ; Hernandez‐Apaolaza, ; Zhu & Gong, ). By enhancing numerous mechanisms such as carbon and water uptake, stomatal control, water retention and photosynthesis, Si increases cell multiplication, tissue growth and biomass production in drought‐stressed plants (Adatia & Besford, ; Chen, Yao, Cai, & Chen, ; Haynes, ; Rizwan et al, ; Romero‐Aranda, Jurado, & Cuartero, ).…”

Silicon Supplementation Alters the Composition of Herbivore Induced Plant Volatiles and Enhances Attraction of Parasitoids to Infested Rice Plants

“…Evidence of this is the fact that plants have evolved influx, efflux and channel-type transporters to actively uptake Si (Ma and Yamaji, 2006, 2015; Trembath-Reichert et al, 2015; Vivancos et al, 2016) as well as that yield increases when plant-available Si is added to the growing medium (Tavakkoli et al, 2011). The beneficial roles of Si to various plants have been the subject of extensive research and include alleviation of abiotic stresses such as drought (Marques et al, 2016), metal toxicity, and micronutrient deficiency (Hernandez-Apaolaza, 2014); and biotic stress from pathogens (Winslow, 1992; Vivancos et al, 2015) and herbivores (Reynolds et al, 2009, 2016; Ye et al, 2013). To date, there is increasing evidence of Si priming plants for defense against herbivore attack (Reynolds et al, 2009; Hartley and DeGabriel, 2016).…”