The BAHD acyltransferase family is a class of proteins in plants that can acylate a variety of primary and specialized secondary metabolites. The typically acylated products have greatly improved stability, lipid solubility, and bioavailability and thus show significant differences in their physicochemical properties and pharmacological activities. Here, we review the protein structure, catalytic mechanism, and phylogenetic reconstruction of plant BAHD acyltransferases to describe their family characteristics, acylation reactions, and the processes of potential functional differentiation. Moreover, the potential applications of the BAHD family in human activities are discussed from the perspectives of improving the quality of economic plants, enhancing the efficacy of medicinal plants, improving plant biomass for use in biofuel, and promoting stress resistance of land plants. This review provides a reference for the research and production of plant BAHD acyltransferases.

In the current study, the impact of silicon nanoparticles on germination characteristics and key growth parameters was investigated in Moso bamboo seedlings under cadmium (Cd) stress. The seeds were germinated at a concentration of 100 μM Cd alone and in combination with two levels of SiO2 NPs (100 and 200 μM), and the results were compared with those from a control treatment. The results indicated that SiO2 NPs significantly improved germination characteristics (GP, GR, and GI) under Cd toxicity but also led to increased mean germination time (MGT). On the other hand, the results indicated that the seedling growth indexes, seedling biomass and vigor indexes of Moso bamboo improved under a combination of 100 μM Cd and silicon nanoparticles. We concluded that SiO2 NPs could ameliorate cadmium toxicity during seed germination and that the enhanced germination parameters improved seedling growth in Moso bamboo under Cd toxicity. We also found that SiO2 NPs at 200 μM rather than 100 μM had a greater beneficial impact on the seed germination and the seedling growth under the Cd stress of 100 μM. Thus, the use of SiO2 NPs may help in controlling Cd toxicity at the stages of seed germination and seedling growth in Moso bamboo (Phyllostachys edulis).

Bamboo forests cover a remarkable area of Chinese forestland. Recently, titanium dioxide nanoparticles (TiO₂ NPs) have been used for plant protection against abiotic stress. In this study, an in vitro tissue culture experiment was conducted to determine the impact of titanium on plant tolerance to two different heavy metals (Cu and Pb). Bamboo plants (Arundinaria pygmaea L.) were grown using five concentrations of TiO₂ NPS (0, 50, 80, 100, and 150 µM) without or with 100 µM Cu and 100 µM Pb for 30 days. The results showed that while Cu and Pb increased the generation of Reactive oxygen species (ROS) compounds in plants, TiO₂ NP treatments played a positive role in reducing oxidative stress, as indicated by the decrease in ROS compounds, the extent of lipoperoxidation, and soluble proteins. On the other hand, the use of TiO₂ NPs increased the total antioxidant capacity, chlorophyll content and general plant biomass. Moreover, the addition of TiO₂ NPs significantly reduced Cu, and Pb accumulation in roots, stems, and shoots. We concluded that TiO₂ NPs have the ability to reduce oxidative stress in plants by increasing the antioxidant capacity, improving the level of injury, and protecting cell membranes via reducing lipoperoxidation (reduction of Malondialdehyde (MDA) content). However, the results indicated that the efficiency of TiO₂ NPs was related to the type and concentration of heavy metal, as TiO₂ NPs were more effective for Cu than Pb. Additionally, a high concentration of TiO₂ NPs resulted in the greatest enhancement in plant growth and development under heavy metal stress.

In addition to regulating plant growth and development, phytohormones play an essential role in the response to abiotic and biotic stress – especially heavy metal stress. In response to environmental stressors, phytohormones act as signaling molecules in both exogenous and endogenous signaling pathways. In parts of the rhizosphere, phytohormones have an exogenous role, and when regulating plant growth and development, they have an endogenous role. Phytohormones and their associated signaling pathway network are involved in plant responses to heavy metal stress. These molecules can improve the plant defense system by increasing antioxidant enzyme activity and degrading lipoperoxidation and H2O2. Phytohormones are divided into classical phytohormones such as auxins, ethylene, gibberellins, and cytokinins, that have been investigated for many years and the new members, such as jasmonates, brassinosteroids, and strigolactones, which have been little studied. In this review article, we investigated the main mechanisms involved in the amelioration of heavy metals by the three new phytohormones to provide more knowledge about their detoxification mechanisms.

The recent emerging evidence reveals that titanium dioxide nanoparticles (TiO₂ NPs) can be used as a wastewater treatment. This study provides new information about the possible detoxification role of TiO₂ NPs as a wastewater treatment in plants under heavy metal stress, with an emphasis on the mechanisms involved. Here, we investigated the effects of TiO₂ NPs as one wastewater treatment on a bamboo species (Arundinaria pygmaea L.) under in vitro Cadmium (Cd) toxicity conditions. A factorial experiment was conducted in a completely randomized design with four replications of four concentrations of Cd (50, 100, 200, and 300 µM) alone and in combination with 100 and 200 µM TiO₂ NPs as two wastewater treatments, as well as a control treatment. The results indicated that TiO₂ NPs concentrations enhanced enzymatic and non-enzymatic antioxidant activities and proline accumulation as well as reducing hydrogen peroxide (H₂O₂), superoxide radical (O₂^•−), and malondialdehyde (MDA) levels, which led to improved photosynthetic parameters with an eventual increase in plant biomass as compared to the control treatment. Therefore, TiO₂ NPs improved the photosynthetic parameters of bamboo under Cd toxicity, which led to an increase in plant biomass. We concluded that the wastewater treatments of TiO₂ NPs improved bamboo biomass through the scavenging of reactive oxygen species (ROS) compounds (H₂O₂ and O₂^•−), which was induced by the stimulation of the antioxidant capacity of the plant. TiO₂ also protected cell membranes by reducing lipoperoxidation in bamboo under Cd toxicity. The concentration of 200 µM TiO₂ NPs had the most impact in reducing Cd toxicity.

This study focused on the physiological regulation and mechanism of exogenous 5-aminolevulinic acid (5-ALA) in the late growth of P. heterophylla. In the middle of May, different concentrations of 5-ALA (0, 10, 20, 50 mg·L⁻¹) were sprayed on the leaves. The effects of 5-ALA on tuberous root growth, antioxidant enzyme system, gas exchange, photosynthetic pigment contents and photosynthetic characteristics were measured from 23 May to 13 June. A concentration of 20 mg·L⁻¹ of 5-ALA led to a significant increase in the yield of fresh root and biomass allocation at 38.12% and 25.07%, respectively, in comparation with the control (0 mg·L⁻¹). The moderate concentration of 5-ALA statistically stimulated antioxidation activities. 5-ALA treatment enhanced photosynthetic activity and reduced photodamage. Compared to the control, there were increases in the chlorophyll fluorescence parameters of P. heterophylla under 5-ALA treatment. Moreover, 20 mg·L⁻¹ of 5-ALA significantly changed the kinetic parameters of fluorescence. It enhanced the light absorption and distribution efficiency of PSII and the activities of leaves, resulting in alleviating photoinhibition by the excess excitation energy. The correlation indicated that there was a significant positive correlation between the yield of tuberous roots and biomass allocation, P_n and catalase (CAT), and a negative correlation between the yield of tuberous roots and malondialdehyde (MDA). The appropriate 5-ALA concentration in the late growth stage of P. heterophylla effectively enhanced the net photosynthetic capacity, mainly resulting from the enhancement of PSII photochemical activity to promote the increases in excitation energy absorption, capture and electron transfer efficiency of the leaves. Finally, 5-ALA treatment can increase the photochemical activity of PSII in the whole leaf and ultimately delay the senescence of P. heterophylla.