Proline Spray Relieves the Adverse Effects of Drought on Wheat Flag Leaf Function.

Drought stress is one of the key factors restricting crop yield. The beneficial effects of exogenous proline on crop growth under drought stress have been demonstrated in maize, rice, and other crops. However, little is known about its effects on wheat under drought stress. Especially, the water-holding capacity of leaves were overlooked in most studies. Therefore, a barrel experiment was conducted with wheat at two drought levels (severe drought: 45% field capacity, mild drought: 60% field capacity), and three proline-spraying levels (0 mM, 25 mM, and 50 mM). Meanwhile, a control with no stress and no proline application was set. The anatomical features, water-holding capacity, antioxidant capacity, and proline content of flag leaves as well as grain yields were measured. The results showed that drought stress increased the activity of catalase and peroxidase and the content of proline in flag leaves, lessened the content of chlorophyll, deformed leaf veins, and decreased the grain yield. Exogenous proline could regulate the osmotic-regulation substance content, chlorophyll content, antioxidant enzyme activity, water-holding capacity, and tissue structure of wheat flag leaves under drought stress, ultimately alleviating the impact of drought stress on wheat yield. The application of proline (25 mM and 50 mM) increased the yield by 2.88% and 10.81% under mild drought and 33.90% and 52.88% under severe drought compared to wheat without proline spray, respectively.

Draft Genome Sequence Resource of Sweet Cherry Virescence Phytoplasma Strain SCV-TA2020 Associated with Sweet Cherry Virescence Disease in China.

Sweet cherry virescence phytoplasma strain SCV-TA2020, a related strain of 'Candidatus Phytoplasma ziziphi', is a pathogen associated with sweet cherry virescence disease in China. Here, we provide the first-draft genome sequence of SCV-TA2020, which consists of 775,344 bases, with a GC content of 23.21%. This will provide a reference for understanding the host selection and diversity of host-specific symptoms of 16SrV-B subgroup phytoplasmas.

Two new diterpenoids with their antiproliferative activities from the supercritical fluid extraction of Croton crassifolius root.

Supercritical fluid extraction was applied to obtain the lower polarity extracts from Croton crassifolius roots, and chemical investigation of which led to the isolation and identification of two new diterpenoids, named crassifolius P (1) and crassifolius Q (2). In vitro anti-proliferative activities of compounds 1 and 2 on A549, Hep-G2 and Hela tumor cell lines were evaluated. The two new compounds exhibited obvious selectivity to tumor cells with IC50 values ranging from 20.43 ± 1.18 µM to 25.72 ± 1.32 µM.

Croton tiglium essential oil compounds have anti-proliferative and pro-apoptotic effects in A549 lung cancer cell lines.

As a traditional Chinese medicine, Croton tiglium has the characteristics of laxative, analgesic, antibacterial and swelling. This study aimed to analyze the chemical composition of C. tiglium essential oil (CTEO) extracted from the seeds of C. tiglium and its cytotoxicity and antitumor effect in vitro. Supercritical CO2 fluid extraction technology was used to extract CTEO and the chemical constituents of the essential oil were identified by comparing the retention indices and mass spectra data taken from the NIST library with those calculated based on the C7-C40 n-alkanes standard. In vitro cytotoxicity of the CTEO was assessed against cancer cell lines (A549) and the human normal bronchial epithelial cells (HBE) using the CCK-8 assay. Proliferation was detected by colony formation experiments. Wound scratch and cell invasion assays were used to detect cell migration and invasion. Levels of apoptotic markers, signaling molecules, and cell cycle regulators expression were characterized by Western blot analysis. As the results, twenty-eight compounds representing 92.39% of the total oil were identified in CTEO. The CTEO has significant antitumor activity on A549 cancer cells (IC50 48.38 µg/mL). In vitro antitumor experiments showed that CTEO treatment significantly inhibited the proliferation and migration of A549 cells, disrupted the cell cycle process, and reduced the expression levels of cyclin A, cyclin B and CDK1. CTEO can also reduce mitochondrial membrane potential, activate caspase-dependent apoptosis pathway, and finally induce apoptosis. CTEO may become an effective anti-cancer drug and will be further developed for cancer treatment.

Linearly thermal-tunable near-infrared ultra-narrowband metamaterial perfect absorber with low power and a large modulation depth based on a four-nanorod-coupled a-silicon resonator.

The bandwidths of thermal-tunable metamaterial perfect absorbers (MPAs) based on the phase change materials such as Ge2Sb2Te5 and VO2 are usually hundreds of nanometers at near-infrared frequency. Amorphous silicon (a-Si) provides the approach to achieve linearly thermal-tunable ultra-narrowband MPAs, if the absorption band is narrow enough. Four-nanorod-coupled a-Si resonators are proposed in this Letter. An absorption band at 1064 nm is obtained with ultra-narrow bandwidth (FWHM) only 1.4 nm by exciting the coupled magnetic dipole (CMD) mode, which exhibits great linearity to the temperature. In addition, the thermo-optical sensitivity (S=Δλ/ΔT) is about 0.08 nm/°C. The figure of merit of the thermal tunability performance FOM=S/FWHM=0.06. As a modulator, the critical temperature of absorptivity at 1064 nm is only 40°C, which is much lower than the Ge2Sb2Te5 (GST) and VO2. In addition, the modulation depth is up to 82% at near-infrared frequency.

Theoretical excitation of 2-D (1, 1) cavity mode with asymmetric sword-shaped notched square resonators for metamaterial perfect multiband absorbers in infrared range.

1-D cavity modes in 1-D resonators, such as strips, have been used to design multiband metamaterial perfect absorbers. As for 2-D resonators, such as squares and crosses, most studies still focus on exciting the 1-D cavity modes. In this paper, a symmetry-breaking idea is proposed for 2-D cavity mode excitation. An asymmetric sword-shaped notched square resonator is proposed to excite a new 2-D (1, 1) cavity mode, in addition to the 1-D (1, 0) and (3, 0) cavity modes. Thus, a triple-band MPA was successfully produced with average absorptivity of 98.8% in the infrared range. The 2-D cavity mode provides better performance as a biosensor than the 1-D cavity modes do. To obtain more absorption bands, a six-band metamaterial perfect absorber with average absorptivity of 97.2% was successfully produced by combining two sword-shaped notched square resonators with different sizes. A nine-band metamaterial perfect absorber was successfully produced with average absorptivity of 94.5% by combining three sword-shaped notched square resonators with different sizes.