Titanium Application Increases Phosphorus Uptake Through Changes in Auxin Content and Root Architecture in Soybean (Glycine Max L.)

Abstract

Phosphorus (P) is an essential macronutrient needed for plant growth, development, and production. A deficiency of P causes a severe impact on plant development and productivity. Several P-based fertilizers are being used in agriculture but limited uptake of P by the plant is still a challenge to be solved. Titanium (Ti) application increases the nutrient uptake by affecting the root growth; however, the role of Ti in plant biology, specifically its application under low light and phosphorus stress, has never been reported. Therefore, a pot study was planned with foliar application of Ti (in a different concentration ranging from 0 to 1,000 mg L–1) under different light and P concentrations. The result indicated that under shade and low P conditions the foliar application of Ti in different concentrations significantly improves the plant growth parameters such as root length, root surface area, root dry matter, and shoot dry matters. The increase was observed to be more than 100% in shade and low P stressed soybean root parameter with 500 mg L–1 of Ti treatment. Ti was observed to improve the plant growth both in high P and low P exposed plants, but the improvement was more obvious in Low P exposed plants. Auxin concentration in stressed and healthy plant roots was observed to be slightly increased with Ti application. Ti application was also observed to decrease rhizosphere soil pH and boosted the antioxidant enzymatic activities with an enhancement in photosynthetic efficiency of soybean plants under shade and P stress. With 500 mg L–1 of Ti treatment, the photosynthetic rate was observed to improve by 45% under shade and P stressed soybean plants. Thus, this work for the first time indicates a good potential of Ti application in the low light and P deficient agricultural fields for the purpose to improve plant growth and development parameters.

Titanium nanoparticles activate a transcriptional response in Arabidopsis that enhances tolerance to low phosphate, osmotic stress and pathogen infection

“…Transcriptomic microarray analysis in Arabidopsis treated with TiO 2 showed increased expression of Fe-S assembly genes ( Tumburu et al., 2017 ) which could increase the level of the electron transport chains needed for photosynthesis ( Balk and Pilon, 2011 ). Improved nitrogen (N), Fe, and phosphorus (P) uptake in response to Ti treatment has been reported for several plant species including wheat ( Triticum aestivum ), tomato ( Solanum lycopersicum ), soybean ( Glycine max ) and rice ( Oryza sativa ), ( Zahra et al., 2017 ; Dağhan et al., 2020 ; Hussain et al., 2021 ; Carbajal-Vázquez et al., 2022 ). In the case of P uptake, the effect of Ti has been attributed to effects on root architecture ( Wei et al., 2020 ; Hussain et al., 2021 ) and changes in root exudates composition, which increase soil exploration capacity and P availability ( Zahra et al., 2015 ; Zahra et al., 2017 ; Zahra et al., 2019 ).…”

“…Improved nitrogen (N), Fe, and phosphorus (P) uptake in response to Ti treatment has been reported for several plant species including wheat ( Triticum aestivum ), tomato ( Solanum lycopersicum ), soybean ( Glycine max ) and rice ( Oryza sativa ), ( Zahra et al., 2017 ; Dağhan et al., 2020 ; Hussain et al., 2021 ; Carbajal-Vázquez et al., 2022 ). In the case of P uptake, the effect of Ti has been attributed to effects on root architecture ( Wei et al., 2020 ; Hussain et al., 2021 ) and changes in root exudates composition, which increase soil exploration capacity and P availability ( Zahra et al., 2015 ; Zahra et al., 2017 ; Zahra et al., 2019 ). There is little information regarding the effect of Ti treatment on the uptake of nutrients other than N, P, and Fe.…”

Comparative physiological and transcriptomics analysis revealed crucial mechanisms of silicon-mediated tolerance to iron deficiency in tomato

“…Under Fe deficiency, the values of FPSII, ETR and qP decreased significantly, but increased after the addition of Si (Supplementary Table 3), indicating that the Si application effectively increased the development and activity of PSII reaction center, which was conducive to using more energy for PSII electron transfer and improving the efficiency of photosynthetic pigments in converting light energy into chemical energy. NPQ decreased under Fe deficiency and Si application increased NPQ, indicating that Fe deficiency damaged the photoprotective system, limiting the dissipation of excess light energy and increasing the risk of damage to the photosystem, while Si application effectively protected the photoprotective system and reduced the damage to the photosystem from the accumulation of excess light energy (Debona et al, 2017;Hussain et al, 2021).…”

“…Plant roots mainly absorb silicic acid (H 4 SiO 4 ), which is then transported through the xylem to shoot, eventually forming amorphous Si (SiO 2 •nH 2 O) deposited in the cell wall or intercellular space (Zhang et al, 2018;Khan et al, 2021). Dissolved Si (H 4 SiO 4 ), can be readily taken up by plants and it plays an important role as an alleviator of both biotic and abiotic stress (Ahmad et al, 2019;Ahanger et al, 2020;Ahammed and Yang, 2021;Hussain et al, 2021). The absorption of Si by plants consists of active absorption and passive absorption, and both types may exist simultaneously (Ahmed et al, 2014;Zaid et al, 2018).…”

Shading decreases lodging resistance of wheat under different planting densities by altering lignin monomer composition of stems

“…Due to shading stress, the expression abundance of PAL, 4CL, F5H, and LAC dropped, reducing the lignin content in the tea plant (Teng et al, 2021). Low light stress reduced the expression of C3'H, CCR, CCoAOMT, and POD and decreased the activities of POD, CAD, 4CL and PAL, finally reducing the lignin content in soybean stems (Liu et al, 2018;Hussain et al, 2021). However, it is unclear about the mechanisms of lignin monomers composition in response to low light stress in wheat under different planting densities.…”