Silicon accumulated in the shoots results in down-regulation of phosphorus transporter gene expression and decrease of phosphorus  uptake in rice

Combined Silicon-Phosphorus Fertilization Affects the Biomass and Phytolith Stock of Rice Plants

“…On the other hand, P supply likely increased plant growth and fecundity as well as root growth (Lambers et al, 2006;Brown et al, 2012). Indeed, low P levels (i.e., Si m P 0 or Si h P 0 ; Table 3) did not significantly increase rice biomass regardless of plant part (Tables 2 and 3), confirming that rice growth was clearly limited at low P supply (Ma and Takahashi, 2002;Ma, 2004;Cooke and Leishman, 2016;Agostinho et al, 2017;Hu et al, 2018) even with increasing the addition of Si fertilizer. Excessive inorganic P within rice plant inhibits enzyme reactions, induces abnormal osmotic pressure in plant cell, which further decreases rice growth (Ma and Takahashi, 1990).…”

“…This trend is in accordance with Ma and Takahashi (1990) who reported that Si content of rice shoots decreased with increasing P availability in soil (Tables 2 and 3). As here discussed above, this trend of decreasing Si deposition in plant tissues resulted from dilution caused by increased plant growth following P application and the molecular mechanism of down-regulating the expression of P transporter gene, OsPT6 in rice (Hu et al, 2018). Since shoot biomass significantly increased following P addition, our data thus suggest that combined Si-P fertilization contributes to increased Si bioavailability in soil, Si root uptake, phytolith formation, and rice plant biomass, which, in turn, increases the stock of phytolith production in plants, while this effect is limited at the high P levels.…”

“…Yet once available P content increases up to 17.8-20.3 mg kg −1 at P h level ( Table 2), the increase in bioavailable Si is beneficial to rice plants by decreasing P uptake (data not shown; Ma and Takahashi, 1989;Owino-Gerroh and Gascho, 2005;Greger et al, 2018), which, in turn, decreases plant P content (Ma and Takahashi, 1990). This Si-induced decrease in plant P uptake can also result from the molecular mechanism of down-regulating the expression of P transporter gene, OsPT6 in rice (Hu et al, 2018). The Si-P interaction thus contributes to increase rice biomass at Si m P m , Si m P h , and Si h P h levels ( Table 5), suggesting Si supply may alleviate excessive P application.…”

“…However, P fertilization also plays an important role in improving yields and promoting plant precocity (George et al, 2001;Lambers et al, 2006;Hammond and White, 2008). In paddy soils, Si and P fertilization could alleviate P deficiency, increase P uptake by plants (Ma and Takahashi, 1990;Liang et al, 2007;Hu et al, 2018), and enhance plant available Si in soil, hence improving crop yields Klotzbücher et al, 2015;Carey and Fulweiler, 2016;Li et al, 2019). Furthermore, plant available Si content in soil may increase after P supply.…”

Silicon Compensates Phosphorus Deficit-Induced Growth Inhibition by Improving Photosynthetic Capacity, Antioxidant Potential, and Nutrient Homeostasis in Tomato

“…Analysis of major element concentrations revealed that exogenous Si application under LP stress not only increased Si uptake but also enhanced the concentrations of most essential elements (K, Na, Ca, Mg, Fe, and Mn) in different tissues (roots, leaves, and stems). These results reveal that Si mitigates LP stress by improving photosynthetic capacity, antioxidant potential, and nutrient homeostasis and that it can be used for agronomic management of vegetable crops in P-deficient soils.Agronomy 2019, 9, 733 2 of 16 activation/inactivation, signaling, and redox reactions [2][3][4]. However, P concentration in most soils is very low, which necessitates P fertilization from synthetic sources [5].…”