Hydrogen sulphide (H2S) is emerging as a potential messenger molecule involved in modulation of physiological processes in animals and plants. In this report, the role of H2S in modulating photosynthesis of Spinacia oleracea seedlings was investigated. The main results are as follows. (i) NaHS, a donor of H2S, was found to increase the chlorophyll content in leaves. (ii) Seedlings treated with different concentrations of NaHS for 30 d exhibited a significant increase in seedling growth, soluble protein content, and photosynthesis in a dose-dependent manner, with 100 μM NaHS being the optimal concentration. (iii) The number of grana lamellae stacking into the functional chloroplasts was also markedly increased by treatment with the optimal NaHS concentration. (iv) The light saturation point (Lsp), maximum net photosynthetic rate (Pmax), carboxylation efficiency (CE), and maximal photochemical efficiency of photosystem II (Fv/Fm) reached their maximal values, whereas the light compensation point (Lcp) and dark respiration (Rd) decreased significantly under the optimal NaHS concentration. (v) The activity of ribulose-1,5-bisphosphate carboxylase (RuBISCO) and the protein expression of the RuBISCO large subunit (RuBISCO LSU) were also significantly enhanced by NaHS. (vi) The total thiol content, glutathione and cysteine levels, internal concentration of H2S, and O-acetylserine(thiol)lyase and L-cysteine desulphydrase activities were increased to some extent, suggesting that NaHS also induced the activity of thiol redox modification. (vii) Further studies using quantitative real-time PCR showed that the gene encoding the RuBISCO large subunit (RBCL), small subunit (RBCS), ferredoxin thioredoxin reductase (FTR), ferredoxin (FRX), thioredoxin m (TRX-m), thioredoxin f (TRX-f), NADP-malate dehydrogenase (NADP-MDH), and O-acetylserine(thiol)lyase (OAS) were up-regulated, but genes encoding serine acetyltransferase (SERAT), glycolate oxidase (GYX), and cytochrome oxidase (CCO) were down-regulated after exposure to the optimal concentration of H2S. These findings suggest that increases in RuBISCO activity and the function of thiol redox modification may underlie the amelioration of photosynthesis and that H2S plays an important role in plant photosynthesis regulation by modulating the expression of genes involved in photosynthesis and thiol redox modification.
The first catalytic direct alkylation of allylic C-H bonds via Pd(II)-catalysis is described in the absence of base. Polysubstituted cyclic compounds can also be constructed by the intramolecular direct allylic alkylation.
Abstract. The Atmospheric Pollution and Human Health in a Chinese
Megacity (APHH-Beijing) programme is an international collaborative project
focusing on understanding the sources, processes and health effects of air
pollution in the Beijing megacity. APHH-Beijing brings together leading China
and UK research groups, state-of-the-art infrastructure and air quality
models to work on four research themes: (1) sources and emissions of air
pollutants; (2) atmospheric processes affecting urban air pollution; (3) air
pollution exposure and health impacts; and (4) interventions and solutions.
Themes 1 and 2 are closely integrated and support Theme 3, while Themes 1–3
provide scientific data for Theme 4 to develop cost-effective air pollution
mitigation solutions. This paper provides an introduction to (i) the
rationale of the APHH-Beijing programme and (ii) the measurement and
modelling activities performed as part of it. In addition, this paper
introduces the meteorology and air quality conditions during two joint
intensive field campaigns – a core integration activity in APHH-Beijing. The
coordinated campaigns provided observations of the atmospheric chemistry and
physics at two sites: (i) the Institute of Atmospheric Physics in central
Beijing and (ii) Pinggu in rural Beijing during 10 November–10 December 2016 (winter) and 21 May–22 June 2017 (summer). The campaigns were
complemented by numerical modelling and automatic air quality and low-cost
sensor observations in the Beijing megacity. In summary, the paper provides
background information on the APHH-Beijing programme and sets the scene for
more focused papers addressing specific aspects, processes and effects of
air pollution in Beijing.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.