Physiological and Morphological Responses of Hydroponically Grown Pear Rootstock Under Phosphorus Treatment

Abstract

Phosphorus (P) is an essential macronutrient for the growth and development of fruit trees, playing an important role in photosynthesis, nucleic acid synthesis, and enzyme activity regulation. The plasticity of plant phenotypic has been investigated in diverse species under conditions of P-deficiency or P-excess. Based on these researches, P level fluctuations in different species result in different characteristics of the response. Nevertheless, little is known about the response of pear seedling rootstock (Pyrus betulifolia Bunge) to the changing of P levels. To explore the effects of different levels of P on the growth of pear seedling rootstock, we performed the hydroponic assays to determine and analyze the biological indexes including growth parameters, photosynthetic rate, root and shoot morphological traits, and concentrations of macro- and micronutrients. The results show that either deficiency or excess of P inhibited the growth and development of pear seedling rootstock. Root growth (down 44.8%), photosynthetic rate (down 59.8%), and acid phosphatase (ACP) activity (down 44.4%) were inhibited under the P-deficiency conditions (0mM), compared with normal P conditions (1mM). On the other hand, dark green leaves, suppression of root elongation (down 18.8%), and photosynthetic rate (down 25%) were observed under regimes of excessive P, compared with normal P conditions (1mM). Furthermore, the root concentration of not only P, but also those of other mineral nutrients were affected by either P treatment. In brief, these results indicated that a careful choice of P fertilizer supply is crucial to ensuring normal growth and development of pear seedling rootstock.

Analysis of physiological response and differential protein expression of Paramichelia baillonii saplings under phosphorus deficiency

“…Consistent with these findings, the present study demonstrates a significant reduction in total root length, total root surface area, and total root volume, excluding total root diameter, under deficient or low P conditions (Table 1). This underscores the plasticity of the root system architecture, likely influenced by P deficiency's impact on the carbon budget (Chen et al, 2021). Physiological plasticity plays a crucial role, primarily in optimizing the uptake of mobile ions, particularly nitrate.…”

A reagent-free phosphate chemiresistive sensor using carbon nanotubes functionalized with crystal violet

“…Several studies have reported that a deficiency of phosphorus can result in a decrease in leaf number, reduced leaf area, alteration of root/shoot biomass and stunted plant growth. [2][3][4] For instance, phosphorus deficiency (<0.5 mM) in pear plants has a significant effect on root morphology and growth, but the exact effect depends on the plant species. 2 However, excess phosphorus (>5 mM) can also lead to delayed flowering and dark colored leaves in pear plants.…”

“…[2][3][4] For instance, phosphorus deficiency (<0.5 mM) in pear plants has a significant effect on root morphology and growth, but the exact effect depends on the plant species. 2 However, excess phosphorus (>5 mM) can also lead to delayed flowering and dark colored leaves in pear plants. 2 Furthermore, the requirement for phosphorus varies depending on the plant and the growing methods, like aquaponics needing less phosphorus compared to hydroponics.…”

“…2 However, excess phosphorus (>5 mM) can also lead to delayed flowering and dark colored leaves in pear plants. 2 Furthermore, the requirement for phosphorus varies depending on the plant and the growing methods, like aquaponics needing less phosphorus compared to hydroponics. 1,2,[4][5][6][7] For instance, one study reported that the average concentrations of phosphate (PO 4 -P) used in the aquaponic and hydroponic systems were 20 mg l −1 (0.62 mM) and 149 mg l −1 (4.62 mM), respectively.…”

“…2 Furthermore, the requirement for phosphorus varies depending on the plant and the growing methods, like aquaponics needing less phosphorus compared to hydroponics. 1,2,[4][5][6][7] For instance, one study reported that the average concentrations of phosphate (PO 4 -P) used in the aquaponic and hydroponic systems were 20 mg l −1 (0.62 mM) and 149 mg l −1 (4.62 mM), respectively. 3 Therefore, the phosphorus content should be closely monitored in aquaponic and hydroponic systems.…”