A novel formaldehyde metabolic pathway plays an important role during formaldehyde metabolism and detoxification in tobacco leaves under liquid formaldehyde stress.
Plant physiology and biochemistry : PPB
Tobacco and Arabidopsis are two model plants often used in botany research. Our previous study indicated that the formaldehyde (HCHO) uptake and assimilation capacities of tobacco leaves were weaker than those of Arabidopsis leaves. After treatment with a 2, 4 or 6 mM HCHO solution for 24 h, detached tobacco leaves absorbed approximately 40% of the HCHO from the treatment solution. (13)C-NMR analysis detected a novel HCHO metabolic pathway in 2 mM H(13)CHO-treated tobacco leaves. [4-(13)C]Asn, [3-(13)C]Gln and [U-(13)C]oxalic acid (OA) were produced from this pathway after H(13)COOH generation during H(13)CHO metabolism in tobacco leaves. Pretreatments of cyclosporin A (CSA) and dark almost completely inhibited the generation of [4-(13)C]Asn, [3-(13)C]Gln and [U-(13)C]OA from this pathway but did not suppressed the production of H(13)COOH in 2 mM H(13)CHO-treated tobacco leaves. The evidence suggests that this novel pathway has an important role during the metabolic detoxification of HCHO in tobacco leaves. The analysis of the chlorophyll and Rubisco contents indicated that CSA and dark pretreatments did not severely affect the survival of leaf cells but significantly inhibited the HCHO uptake by tobacco leaves. Based on the effects of CSA and dark pretreatments on HCHO uptake and metabolism, it is estimated that the contribution of this novel metabolic pathway to HCHO uptake is approximately 60%. The data obtained from the (13)C-NMR analysis revealed the mechanism underlying the weaker HCHO uptake and assimilation of tobacco leaves compared to Arabidopsis leaves.
10.1016/j.plaphy.2016.04.028
Formaldehyde assimilation through coordination of the glyoxylate pathway and the tricarboxylic acid cycle in broad bean roots.
Min Yong,Cao Wenjia,Xiong Yun,Si Zhihao,Khan Dawood,Chen Limei
Plant physiology and biochemistry : PPB
Formaldehyde (HCHO) assimilation in broad bean (Vicia faba L. cv. YD) roots was investigated using C-labeled HCHO followed by C-NMR analysis. Results revealed that HCHO was first oxidized to HCOOH in the roots treated with 2 mM HCHO in a time-dependent manner. Subsequently, a massive signal peak of [2, 4-C]citrate (Cit) and a signal peak of [2, 3-C]succinate (Su) were observed in accompany with an enhancement in the signal intensity of [3-C]Cit. The data suggested that the glyoxylate pathway and the tricarboxylic acid (TCA) cycle functioned simultaneously in the subsequent assimilation of HCOOH. The yield of [2, 4-C]Cit accounted for more than 80% of the total metabolites. The activity of isocitrate lyase (ICL), a key enzyme in the glyoxylate pathway, was stimulated by HCHO in a dosage-dependent manner. As a result, [2, 4-C]Cit production was increased significantly in YD roots treated with high concentrations (4 and 6 mM) of HCHO. Moreover, induction of the ICL activity by methanol resulted in a simultaneous elevation in the production of [2, 4-C]Cit and [3-C]Cit in methanol-pretreated roots under 2 mM HCHO stress. Pretreatment of roots with cyclosporin A, which hinders the transport of C-enriched compounds into mitochondria, caused a notable decline in the signal peak and yield of [2, 4-C]Cit and consequently induced a notable accumulation of [2, 3-C]Su and an increase in the HCO production (generated from HCOOH oxidation) in HCHO-treated roots. These results suggested that the glyoxylate pathway and the TCA cycle function coordinately in HCHO assimilation in broad bean roots.
10.1016/j.plaphy.2019.02.019
An Aldolase-Catalyzed New Metabolic Pathway for the Assimilation of Formaldehyde and Methanol To Synthesize 2-Keto-4-hydroxybutyrate and 1,3-Propanediol in .
Wang Chuang,Ren Jie,Zhou Libang,Li Zhidong,Chen Lin,Zeng An-Ping
ACS synthetic biology
Formaldehyde (HCHO) is an important intermediate in the metabolism of one-carbon (C1) compounds such as methanol, formate, and methane. The ribulose monophosphate (RuMP) pathway is the most-studied HCHO assimilation route and the 3-hexulose-6-phosphate synthase (Hps) plays an important role for HCHO fixation. In this study, we proposed and selected a pyruvate-dependent aldolase to channel HCHO into 2-keto-4-hydroxybutyrate as an important intermediate for biosynthesis. By combining this reaction with three further enzymes we demonstrated a pyruvate-based C1 metabolic pathway for biosynthesis of the appealing compound 1,3-propanediol (1,3-PDO). This novel pathway is first confirmed using HCHO and pyruvate as substrates. It is then demonstrated in for 1,3-PDO production from HCHO and methanol with glucose as a cosubstrate. This pathway has several decisive advantages over the known metabolic pathways for 1,3-PDO: (1) C1 carbon is directly channeled into a precursor of 1,3-PDO; (2) the use of pyruvate as an acceptor of HCHO is glycerol-independent, circumventing thus the need of coenzyme B as cofactor for glycerol dehydration; (3) the pathway is much shorter and more simple than the recently proposed l-homoserine-dependent pathway, thus avoiding complicated regulations involving precursors for essential amino acids. In addition to proof-of-concept we further improved the host strain by deleting a gene () responsible for the conversion of HCHO to formate, thereby increasing the production of 1,3-PDO from 298.3 ± 11.4 mg/L to 508.3 ± 9.1 mg/L and from 3.8 mg/L to 32.7 ± 0.8 mg/L with HCHO and methanol as cosubstrate of glucose fermentation, respectively. This work is the first study demonstrating a genetically engineered that can directly use HCHO or methanol for the synthesis of 2-keto-4-hydroxybutyrate and its further conversion to 1,3-PDO.
10.1021/acssynbio.9b00102
Foliar uptake and translocation of formaldehyde with Bracket plants (Chlorophytum comosum).
Su Yuhong,Liang Yongchao
Journal of hazardous materials
The foliar uptake and transport of formaldehyde into Bracket plants from air via leaves and roots to external water was investigated in an air-plant-water system. The results indicated that formaldehyde could be quickly taken up by plant tissues, and that formaldehyde accumulated in leaves could be released rapidly back into air when the formaldehyde level in air was diminished. This rapid reversible translocation of formaldehyde between plant leaves and air resulted in high formaldehyde concentrations in leaf dews, depending upon exposure levels of formaldehyde in air. Meanwhile, formaldehyde could be transported from air to plant rhizosphere solution through downward transport. The concentration of formaldehyde in rhizosphere solutions increased with exposure time and the formaldehyde level in air. The efficiency of the leaf extracts to break down formaldehyde increased, probably because of an increase in oxidative potential of the leaf extracts. Taken together, the main mechanism of formaldehyde loss in air can be attributed to the accumulation by (or breakdown in) plant tissues; the removal rate of formaldehyde from air reached 135 μg h(-1) plant(-1) in the experimental condition.
10.1016/j.jhazmat.2015.03.001
Phytoremediation of Formaldehyde from Indoor Environment by Ornamental Plants: An Approach to Promote Occupants Health.
Teiri Hakimeh,Pourzamzni Hamidreza,Hajizadeh Yaghoub
International journal of preventive medicine
BACKGROUND:Formaldehyde is a common hazardous indoor air pollutant which recently raised public concerns due to its well-known carcinogenic effects on human. The aim of this study was to investigate a potted plant-soil system ability in formaldehyde removal from a poor ventilated indoor air to promote dwellers health. METHODS:For this purpose, we used one of the common interior plants from the fern species (), inside a Plexiglas chamber under controlled environment. Entire plant removal efficiency and potted soil/roots contribution were determined by continuously introducing different formaldehyde vapor concentrations to the chamber (0.6-11 mg/m) each over a 48-h period. Sampling was conducted from inlet and outlet of the chamber every morning and evening over the study period, and the average of each stage was reported. RESULTS:The results showed that the plant efficiently removed formaldehyde from the polluted air by 90%-100%, depending on the inlet concentrations, in a long time exposure. The contribution of the soil and roots for formaldehyde elimination was 26%. Evaluation of the plant growing characteristics showed that the fumigation did not affect the chlorophyll content, carotenoid, and average height of the plant; however, a decrease in the plant water content was observed. CONCLUSIONS:According to the results of this study, phytoremediation of volatile organic compound-contaminated indoor air by the ornamental potted plants is an effective method which can be economically applicable in buildings. The fern species tested here had high potential to improve interior environments where formaldehyde emission is a health concern.
10.4103/ijpvm.IJPVM_269_16
Roles of reactive oxygen species and antioxidant enzymes on formaldehyde removal from air by plants.
Liang Hanxiao,Zhao Suya,Liu Kaiyan,Su Yuhong
Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering
The roles of enzymatic reactions and redox reactions caused by reactive oxygen species (ROS) in formaldehyde metabolism in tomatoes and wheat seedlings and the changes in peroxidase (POD) and catalase (CAT) activities in plants were investigated. Differences in the breakdown of added formaldehyde between fresh and boiled plant extracts were determined to calculate the contributions of different removal mechanisms. Two plant seedlings efficiently removed formaldehyde from air when its level varied from 0.65 to 1.91 mg m; meanwhile, the maximum rate at which tomato seedlings transported formaldehyde from air to the rhizosphere solution reached 182.26 µg h kg FW (fresh weight). Metabolism in plants was mainly responsible for the formaldehyde dissipation. The enzymatic contribution to formaldehyde dissipation decreased with increasing shoot exposure time or air formaldehyde level, while the redox contribution increased in importance because of an increasing level of ROS. The different enzymatic antioxidant activities of plants resulted in different levels of ROS and hence different tolerance and removal efficiencies toward formaldehyde. The self-enhancing ability of plants to remove formaldehyde via redox reactions suggested that the formaldehyde removal efficiency could be enhanced by plant adaptation to environmental stress.
10.1080/10934529.2018.1544477
Phytoremediation of formaldehyde by the stems of Epipremnum aureum and Rohdea japonica.
Zuo Lijun,Wu Dan,Yu Le,Yuan Yanping
Environmental science and pollution research international
Decorative plants can efficiently purify formaldehyde and improve the quality of indoor air. The existing studies primarily revealed that the aerial and underground parts of plants' capacity to purify formaldehyde, while the performance of stems is unclear. A formaldehyde fumigation experiment was conducted on Epipremnum aureum and Rohdea japonica in a sealed chamber. Results showed the stems could remove formaldehyde. The efficiency of removal by the stems of each plant was 0.089 and 0.137 mg∙m∙h, respectively, the rate of purification was 40.0 and 61.6%, respectively. Both were related to plant species and the latter was affected by other factors like exposed area. To further explore the mechanism of phytoremediation, the correlation between the concentration of formaldehyde and CO during the experiment was investigated. Results showed when leaves of plants were exposed to formaldehyde, the concentration of CO increased with the decrease in concentration of formaldehyde, and the change in concentration of CO could be used as an indicator of the degree of decontamination of formaldehyde by the plants.
10.1007/s11356-021-16571-x