Photo Fenton RAFT Polymerization of (Meth)Acrylates in DMSO Sensitized by Methylene Blue.

A novel open-to-air photo RAFT polymerization of a series of acrylate and methacrylate monomers mediated by matching chain transfer agent irradiated by far-red light in DMSO is reported. Hydroxyl radical (•OH) generated from methylene blue (MB) sensitized decomposition of H2 O2 via photo-Fenton like-reaction is used for polymerization initiation. The "living/control" characteristic is evidenced by kinetic study, in which a pseudo first order curve and linearly increases of molecular weight with the increase of monomer conversion are observed. The living end-group fidelity is characterized by MALDI-TOF-MS and 1 H NMR results, and confirmed by successful chain extension. The temporary controllability is proved by light on/off switch experiment.

Brassinosteroid-mediated apoplastic H2 O2 -glutaredoxin 12/14 cascade regulates antioxidant capacity in response to chilling in tomato.

Brassinosteroids (BRs) regulate plant development and stress response. Although much has been learned about their roles in plant development, the mechanisms by which BRs regulate plant stress tolerance remain unclear. Chilling is a major stress that adversely affects plant growth. Here, we report that BR positively regulates chilling tolerance in tomato. BR partial deficiency aggravated chilling-induced oxidized protein accumulation, membrane lipid peroxidation, and decrease of maximum quantum efficiency of photosystem II (Fv/Fm). By contrast, overexpression of BR biosynthetic gene Dwarf or treatment with 24-epibrassinolide (EBR) attenuated chilling-induced oxidative damages and resulted in an increase of Fv/Fm. BR increased transcripts of RESPIRATORY BURST OXIDASE HOMOLOG1 (RBOH1) and GLUTAREDOXIN (GRX) genes, and BR-induced chilling tolerance was associated with an increase in the ratio of reduced/oxidized 2-cysteine peroxiredoxin (2-Cys Prx) and activation of antioxidant enzymes. However, RBOH1-RNAi plants failed to respond to EBR as regards to the induction of GRX genes, activation of antioxidant capacity, and attenuation of chilling-induced oxidative damages. Furthermore, silencing of GRXS12 and S14 compromised EBR-induced increases in the ratio of reduced/oxidized 2-Cys Prx and activities of antioxidant enzymes. Our study suggests that BR enhances chilling tolerance through a signalling cascade involving RBOH1, GRXs, and 2-Cys Prx in tomato.

Overexpression of a brassinosteroid biosynthetic gene Dwarf enhances photosynthetic capacity through activation of Calvin cycle enzymes in tomato.

BACKGROUND: Genetic manipulation of brassinosteroid (BR) biosynthesis or signaling is a promising strategy to improve crop yield and quality. However, the relationships between the BR-promoted growth and photosynthesis and the exact mechanism of BR-regulated photosynthetic capacity are not clear. Here, we generated transgenic tomato plants by overexpressing Dwarf, a BR biosynthetic gene that encodes the CYP85A1, and compared the photosynthetic capacity with the BR biosynthetic mutant d (im) and wild type. RESULTS: Overexpression of Dwarf promoted net photosynthetic rate (P N), whereas BR deficiency in d (im) led to a significant inhibition in P N as compared with WT. The activation status of RuBisCO, and the protein content and activity of RuBisCO activase, but not the total content and transcripts of RuBisCO were closely related to the endogenous BR levels in different genotypes. However, endogenous BR positively regulated the expression and activity of fructose-1,6-bisphosphatase. Dwarf overexpression enhanced the activity of dehydroascorbate reductase and glutathione reductase, leading to a reduced redox status, whereas BR deficiency had the contrasting effects. In addition, BR induced a reduction of 2-cystein peroxiredoxin without altering the protein content. CONCLUSIONS: BR plays a role in the regulation of photosynthesis. BR can increase the photosynthetic capacity by inducing a reduced redox status that maintains the activation states of Calvin cycle enzymes.

DWARF overexpression induces alteration in phytohormone homeostasis, development, architecture and carotenoid accumulation in tomato.

Brassinosteroids (BRs) play a critical role in plant growth, development and stress response; however, genetic evidence for the BR-mediated integrated regulation of plant growth still remains elusive in crop species. Here, we clarified the function of DWARF (DWF), the key BR biosynthetic gene in tomato, in the regulation of plant growth and architecture, phytohormone homeostasis and fruit development by comparing wild type, d^(im), a weak allele mutant impaired in DWF, and DWF-overexpressing plants in tomato. Results showed that increases in DWF transcripts and endogenous BR level resulted in improved germination, lateral root development, CO2 assimilation and eventually plant growth as characterized by slender and compact plant architecture. However, an increase in DWF transcript down-regulated the accumulation of gibberellin, which was associated with decreases in leaf size and thickness. BRs positively regulated lateral bud outgrowth, which was associated with decreased transcript of Aux/IAA3, and the ethylene-dependent petiole bending and fruit ripening. Notably, overexpression of DWF did not significantly alter fruit yield per plant; however, increases by 57.4% and 95.3% might be estimated in fruit yield per square metre in two transgenic lines due to their compact architecture. Significantly, BR level was positively related with the carotenoid accumulation in the fruits. Taken together, our results demonstrate that BRs are actively involved in the regulation of multiple developmental processes relating to agronomical important traits.

Apoplastic H2 O2 plays a critical role in axillary bud outgrowth by altering auxin and cytokinin homeostasis in tomato plants.

Although phytohormones such as indole-3-acetic acid (IAA), cytokinin (CK) and strigolactone are important modulators of plant architecture, it remains unclear whether reactive oxygen species are involved in the regulation of phytohormone-dependent axillary bud outgrowth in plants. We used diverse techniques, including transcriptional suppression, HPLC-MS, biochemical methodologies and gene transcript analysis to investigate the signaling pathway for apoplastic hydrogen peroxide (H2 O2 )-induced axillary bud outgrowth. Silencing of tomato RESPIRATORY BURST OXIDASE HOMOLOG 1 (RBOH1) and WHITEFLY INDUCED 1 (WFI1), two important genes involved in H2 O2 production in the apoplast, enhanced bud outgrowth, decreased transcript of FZY - a rate-limiting gene in IAA biosynthesis and IAA accumulation in the apex - and increased the transcript of IPT2 involved in CK biosynthesis and CK accumulation in the stem node. These effects were fully abolished by the application of exogenous H2 O2 . Both decapitation and the silencing of FZY promoted bud outgrowth, and downregulated and upregulated the transcripts for IAA3 and IAA15, and IPT2, respectively. However, these effects were not blocked by treatment with exogenous H2 O2 but by napthaleneacetic acid (NAA) treatment. These results suggest that RBOHs-dependent apoplastic H2 O2 promotes IAA biosynthesis in the apex, which, in turn, inhibits CK biosynthesis and subsequent bud outgrowth in tomato plants.

Microarray and genetic analysis reveals that csa-miR159b plays a critical role in abscisic acid-mediated heat tolerance in grafted cucumber plants.

Root-shoot communication plays a vital role in plant growth, development and adaptation to environmental stimuli. Grafting-induced stress tolerance is associated with the induction of plentiful stress-related genes and proteins; the mechanism involved, however, remains obscure. Here, we show that the enhanced tolerance against heat stress in cucumber plants with luffa as rootstock was accompanied with an increased accumulation of abscisic acid (ABA), down-regulation of a subset of microRNAs (miRNAs) but up-regulation of their target genes and CsHSP70 accumulation in the shoots. Significantly, luffa rootstock and foliar application of ABA both down-regulated csa-miR159b and up-regulated its target mRNAs CsGAMYB1 and CsMYB29-like and CsHSP70 accumulation in cucumber, while ectopic expression of csa-miR159b led to decreased heat tolerance, AtMYB33 transcript and AtHSP70 accumulation in Arabidopsis plants. Taken together, our results suggest that root-originated signals such as ABA could alter miRNAs in the shoots, which have a major role in the post-transcriptional regulation of the stress-responsive genes.

[Analysis of imported malaria cases in Leshan City from 2012 to 2018].

OBJECTIVE: To analyze the epidemiological characteristics of reported malaria cases in Leshan City, so as to provide insights into malaria control. METHODS: The data pertaining to malaria cases and epidemiological individual information in Leshan City from 2012 to 2018 were captured from the National Notifiable Communicable Disease Reporting System and the Information System for Parasitic Diseases Control and Prevention, and a descriptive epidemiological analysis was performed. RESULTS: A total of 34 malaria cases were reported in Leshan City from 2012 to 2018, and all cases were confirmed as imported malaria cases by Sichuan provincial malaria diagnosis reference laboratory. Of all 34 cases, there were 14 vivax malaria cases, 18 falciparum malaria cases, a malariae malaria case and an ovale malaria case. The sites where malaria parasite infections occurred mainly included African areas (accounting for 58.82%) and Southeastern Asian areas (accounting for 29.41%), and the malaria cases were mainly reported in January, February, June and July, which accounted for 65.63% of all cases. The cases included 33 men and a woman, and had ages of 21 to 59 years. The cases'occupations mainly involved overseas peasants, technical workers and businessmen. The duration from onset of malaria to diagnosis ranged from 0 to 31 days, and the percentage of definitive diagnosis was 85.29% at initial diagnosis. CONCLUSIONS: There are no local malaria cases in Leshan City; however, imported malaria cases are reported. The monitoring, management and health education of overseas returners should be further strengthened and malaria training should be improved to enhance the diagnostic and treatment capability in professionals, so as to consolidate malaria control achievements.

[Diagnosis and treatment of an imported case of schistosomiasis haematobium].

OBJECTIVE: To report the diagnosis and treatment of an imported case of schistosomiasis haematobium, including the pathological features of the disease and therapeutic efficacy of praziquantel. METHODS: The data of the patient with schistosomiasis haematobium were collected, and the pathological features of the bladder tissue were observed under a microscope. More-over, the patient was treated with praziquantel, and his urine was collected before and after the treatment. The eggs in the urine were examined by a microscope after sediment and the miracidia were hatched. RESULTS: The patient once worked in Angola for three months, and after returning home he had the symptoms of intermittent painless terminal hematuresis. It was ineffective after anti-inflammatory treatment in a number of hospitals. There were no sand spots discovered under the cystoscope. However, the inflammatory reaction to parasite with a lot of eosinophils infiltration in the bladder mucosa was found on the pathological sections under a microscope, and the egg structure was observed with individual characteristics. The eggs were detected in the urine and the miracidia were hatched before the praziquantel treatment. The hematuria symptoms disappeared after the praziquantel treatment. The eggs were still detected in the urine 7 days post-treatment, but the miracidium could not be hatched. One month and 6 months post-treatment, the eggs were not detected in the urine. CONCLUSIONS: The imported cases of schistosomiasis haematobium are often misdiagnosed, and therefore, it is necessary to strength the health education to the workers overseas and also to improve the ability of diagnosis in medical staff. For the case reported in this paper, there are typical structure of Schistosoma haematobium eggs and egg-granulomas on the pathological sections of bladder tissues. Praziquantel has satisfactory treatment results.

[Effect of control program of human intestinal parasitic diseases in Nanping City].

OBJECTIVE: To understand the epidemic status of human intestinal parasitic diseases and evaluate the effect of the control program in Nanping City, so as to provide an evidence for improving the disease control. METHODS: The villages were selected by the stratified cluster sampling method and the residents in these villages were surveyed for human intestinal parasitic diseases, and kindergartens were also selected and the children in these kindergartens were surveyed for Enterobius vermicularis infection. RESULTS: In 2007, before the control program, 9 851 residents of Nanping City were surveyed, with the parasitic infection rate of 9.10% (896 infection cases), and the infection rate of E. vermicularis of children was 18.56% (328/1 767). From 2011 to 2014, when the control program was performed, 4 679 residents were surveyed, with the infection rate of 4.06% (190 infection cases), and the infection rate of E. vermicularis of children was 3.87% (33/853). After the control program was launched, the infection rates of human intestinal parasites were decreased. The overall parasitic infection rate and hookworm infection rate showed increasing trends by age (χ2 = 49.03 and 53.58 respectively, both P < 0.01). CONCLUSIONS: The infection situation of human intestinal parasites is decreased after the implementation of the control program but the infection rate is still at a high level, and the control work should be strengthened.