BcNAC056 Interacts with BcWRKY1 to Regulate Leaf Senescence in Pak Choi.

Senescence is the final stage of leaf development. For leafy vegetables such as pak choi, leaf senescence is adverse to yield due to the harvest period shortening. However, the regulatory mechanisms of leaf senescence are largely unknown in leafy vegetables. Here, we isolated and characterized a NAC gene, BcNAC056, in pak choi [Brassica campestris (syn. Brassica rapa) ssp. chinensis cv. 49caixin]. BcNAC056-GFP was located in the nucleus at the subcellular level, and BcNAC056 was responsive to leaf senescence and different hormones at the transcriptional level. Heterologous overexpression of BcNAC056 in Arabidopsis promoted leaf senescence, accompanied by the increased expression of senescence-associated genes (SAGs), whereas virus-induced gene silencing-based silencing in pak choi delayed leaf senescence. The following transcriptome analysis showed that heterologous overexpression of BcNAC056 enhanced some AtSAG transcripts in Arabidopsis. Electrophoretic mobility shift assay (EMSA) and dual-luciferase (LUC) reporter assay revealed that BcNAC056 activated SAG12 by directly binding to the promoter. In addition, with the LUC reporter and transient overexpression assays, we proposed that BcNAC056-BcWRKY1 interaction promoted the activation of BcSAG12. Taken together, our findings revealed a new regulatory mechanism of leaf senescence in pak choi.

BcOPR3 Mediates Defense Responses to Biotrophic and Necrotrophic Pathogens in Arabidopsis and Non-heading Chinese Cabbage.

In plants, the salicylic acid (SA) and jasmonic acid (JA) signaling pathways usually mediate the defense response to biotrophic and necrotrophic pathogens, respectively. Our previous work showed that after non-heading Chinese cabbage (NHCC) was infected with the biotrophic pathogen Hyaloperonospora parasitica, expression of the JA biosynthetic gene BcOPR3 is induced; however, its molecular mechanism remains unclear. Here, we overexpressed BcOPR3 in Arabidopsis and silenced BcOPR3 in NHCC001 plants to study the defensive role of BcOPR3 in plants against pathogen invasion. The results showed that overexpression of BcOPR3 increased the susceptibility of Arabidopsis to Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) but enhanced its resistance to Botrytis cinerea. BcOPR3-silenced NHCC001 plants with a 50% reduction in BcOPR3 expression increased their resistance to downy mildew by reducing the hyphal density and spores of H. parasitica. In addition, BcOPR3-partly silenced NHCC001 plants were also resistant to B. cinerea, which could be the result of a synergistic effect of JA and SA. These findings indicate a complicated role of BcOPR3 in the mediating defense responses to biotrophic and necrotrophic pathogens.

Human Respiratory Monitoring Based on Schottky Resistance Humidity Sensors.

Two types of Schottky structure sensors (silicon nanowire (SiNW)/ZnO/reduced graphene oxide (rGO) and SiNW/TiO2/rGO) were designed, their humidity resistance characteristics were studied, and the sensors were applied to detect sleep apnea through breath humidity monitoring. The results show that the resistance of the sensors exhibited significant changes with increasing humidity, the response times of the two sensors within the relative humidity range of 23-97% were 49 s and 67 s, and the recovery times were 24 s and 43 s, respectively. Meanwhile, continuous breathing monitoring results indicate that the sensitivity of the sensors remained basically unchanged during 10 min of normal breathing and simulated apnea. The response of the sensor is still good after 30 days of use. We believe that the Schottky structure composite sensor is a very promising technology for human breathing monitoring.

HLA ASSOCIATIONS IN OBESE WHITE AND BLACK ADULTS.

We summarized HLA-A and -B data from 1095 black and white adult men and women with or without obesity to determine if specific HLA tissue types are overrepresented in obese individuals compared with nonobese. None of the three HLA types (Aw30, B18, Bw35) previously reported to relate to obesity was overrepresented in obese subjects in our study. However, B14 and B41 haplotypes were overrepresented in obese white men compared with nonobese men, and B7 was overrepresented in obese black men compared with nonobese men. Additional research will be required to confirm the HLA associations we found and to determine if methodologic differences could account for the differences among the previous studies.