The aim of this research was to investigate the effect of aluminum (Al) on the plant growth, nutrient uptake, and Al accumulation in Camellia japonica. A hydroponic experiment was performed in a completely randomized design with four concentration of Al (0, 0.5, 1, and 2 mM). After growing 8 weeks in the hydroponic nutrient solution, the fine roots and mature leaves of plants were sampled to analyze the biomass, photosynthetic parameters, nutrients uptake, and Al accumulation. The 0.5, 1, and 2 mM Al supplement presented an increase of 71, 118, and 42% on the root biomass, respectively, comparing to the control. The Alinduced growth stimulation in 0.5 and 1 mM Al treatment of Camellia japonica was associated with increased levels of chlorophyll a and b, promotion of net photosynthesis rate, raised contents of soluble sugar and total soluble protein, and decreased levels of malondialdehyde (MDA) and free proline in both leaves and fine roots. The concentrations of nitrogen (N), phosphorus (P), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) in fine roots of 1 mM Al-treated plants were significantly higher than those in the control plants, whereas the levels of calcium (Ca) and magnesium (Mg) were much lower. The mean Al levels in the 1 mM Al-treated plants were 1587, 7189, and 11,192 mg kg −1 (dry mass, DW) for the 1st/2nd, 3rd/4th mature leaves, and fine roots, respectively. This study indicated that 0.5 and 1 mM Al were beneficial to the growth of Camellia japonica. This Alinduced growth enhancement was presumably associated with the increased uptake of nutrient elements. This study also confirmed Camellia japonica as an Al-accumulator.

Mesenchymal stromal cells (MSCs) widely exist in many tissues and have multiple differentiation potential and immunomodulatory capacities. Recently, MSCs have become promising tools for the treatment of various degenerative disorders and autoimmune diseases. The properties of MSCs could be modified in different microenvironments. Thus, it is important to explore the factors controlling MSC function. The presence of Toll-like receptors (TLRs) in MSCs was demonstrated according to previous studies. Consistently, we also illustrated the expression of TLRs in both murine and human MSCs, and displayed that the expression patterns of TLRs in MSCs from different sources. Furthermore, we explored the role of TLR and TLR signaling pathway in MSCs. Interestingly, activation of TLR4-induced expression of cytokines and some specific genes in MSCs. However, MSCs retained much lower mRNA level compared with macrophages. We explored the expression of CD14 in MSCs from different sources, which played a vital role in TLR4 signaling pathway, and found that MSCs are almost negative for CD14. Moreover, only partial activation of TLR4 signaling pathway was observed in MSCs, with no activation of AKT, NF-κB and P38. Here, in the study we defined TLR expression, function and activation in MSCs, which is critical for designing MSC-based therapies.