Light and zinc application treatment regulates yield and 2-acetyl-1-pyrroline (2AP) formation in fragrant rice

Abstract Background Improving the yield and aroma content of fragrant rice is the focus of fragrant rice research. Light (L) and Zinc (Zn) management generally cause regulations in the 2-acetyl-1-pyrroline (2AP) accumulation in fragrant rice. In addition, Zn promotes rice growth and improves rice yield, which has the potential to compensate for the negative impact of low light on fragrant rice yield. However, the potential of Zn to improve fragrant rice yield and 2AP content under shading conditions has not been verified. Methods Field experiments were conducted in the rice season (May-September) in 2019 to 2021. Two light i.e., normal light (NL) and low light (LL) and four Zn levels i.e., 0 kg Zn ha− 1 (N0), 1 kg Zn ha− 1 (Zn1), 2 kg Zn ha− 1(Zn2), and 3 kg Zn ha− 1 (Zn3), which applied at booting stage was set up. The grain yield, 2AP contents, Zn content in polish rice, photosynthesis related indicators, MDA content, antioxidant enzyme activity and the biochemical parameters related to 2AP formation were investigated. Results Shading reduced yield by 8.74% and increased 2AP content by 24.37%. In addition, shading reduced net photosynthetic rate (Pn), superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and increased proline, γ-aminobutyric acid (GABA), and pyrroline-5-carboxylic acid (P5C), proline dehydrogenase (PDH), △1-pyrroline-5-carboxylic acid synthetase (P5CS), malondialdehyde (MDA). With increasing Zn application levels, yield, 2AP, Zn content in polish rice, Pn, proline, P5C, GABA, PDH, P5CS, SOD, CAT and POD increased, and MDA decreased. Significant L and Zn interaction effect on 2AP content was detected, and both shading and increasing Zn application increased the 2AP content. Conclusion Shading can increase the 2AP content but reduce the yield of fragrant rice. Increasing Zn application under shading conditions can further promote the biosynthesis of 2AP, but the effect of improving yield is limited.</jats:p

Overexpression of a Functional Vicia sativa PCS1 Homolog Increases Cadmium Tolerance and Phytochelatins Synthesis in Arabidopsis

Phytochelatins (PCs) catalyzed by phytochelatin synthases (PCS) are important for the detoxification of metals in plants and other living organisms. In this study, we isolated a PCS gene (VsPCS1) from Vicia sativa and investigated its role in regulating cadmium (Cd) tolerance. Expression of VsPCS1 was induced in roots of V. sativa under Cd stress. Analysis of subcellular localization showed that VsPCS1 was localized in the cytoplasm of mesophyll protoplasts of V. sativa. Overexpression of VsPCS1 (35S::VsPCS1, in wild-type background) in Arabidopsis thaliana could complement the defects of Cd tolerance of AtPCS1-deficent mutant (atpcs1). Compared with atpcs1 mutants, 35S::VsPCS1/atpcs1 (in AtPCS1-deficent mutant background) transgenic plants significantly lowered Cd-fluorescence intensity in mesophyll cytoplasm, accompanied with enhanced Cd-fluorescence intensity in the vacuoles, demonstrating that the increased Cd tolerance may be attributed to the increased PC-based sequestration of Cd into the vacuole. Furthermore, overexpressing VsPCS1 could enhance the Cd tolerance in 35S::VsPCS1, but have no effect on Cd accumulation and distribution, showing the same level of Cd-fluorescence intensity between 35S::VsPCS1 and wild-type (WT) plants. Further analysis indicated this increased tolerance in 35S::VsPCS1 was possibly due to the increased PCs-chelated Cd in cytosol. Taken together, a functional PCS1 homolog from V. sativa was identified, which hold a strong catalyzed property for the synthesis of high-order PCs that retained Cd in the cytosol rather the vacuole. These findings enrich the original model of Cd detoxification mediated by PCS in higher plants

Study on the anti bovine viral diarrhea virus effect of swainsonine extract of Astragalus strictus Grah Ex Bend in vitro

This study was designed to investigate anti-virus action of the swainsonine (SW) extract of Astragalus strictus Grah. Ex Bend on bovine viral diarrhea virus (BVDV). Using cell culture techniques, and combining cytopathic effect (CPE) observation method and methyl thiazolyl tetrazolium (MTT) method to detect the toxicities of different concentrations of SW in bovine kidney primary cells (Madin-Darby Bovine Kidney Cells, MDBK), determine the drug safety concentration and TD50, Testing the comprehensive effect of different concentrations of SW for BVDV by adding swainsonine after virus-and-swainsonine added. The results showed that the TCID50 of BVDV is 10-4.7; there is no toxicity to MDBK when the concentration of SW below 0.256,mg·mL-1, and TD50 is 2.512mg·mL-1; Under the way of comprehensive action, IC50 is 0.782mg·mL-1,TI is 3.21. it showed that the comprehensive effect on BVDV of SW (65.29%, P less than 0.01) is good. The anti-BVDV effect of swainsonine in vitro is good and the antiviral mechanism of SW was speculated to SW inhibit the replication of BVDV proliferation or directly inactivate free BVDV.</jats:p

MACE nano-texture process applicable for both single- and multi-crystalline diamond-wire sawn Si solar cells

The photovoltaic (PV) industry requires efficient cutting of large single and multi-crystalline (sc- and mc-) silicon (Si) wafers. Historically multi-wire slurry sawing (MWSS) dominated, but the higher productivity of diamond-wire-sawing (DWS) holds promise for decreasing PV costs in the future. While surface texturing of DWS wafers is more complicated than of MWSS wafers, especially in mc-Si wafers, nanotexturing has been shown to overcome this challenge. While the benefit of nanotexturing is thus clearer in mc-Si, a universal nano-texture process that also works on sc-Si would simplify and reduce the investments costs of PV production-lines. In this paper, such a nano-texture process is developed using a metal-assisted chemical etch (MACE) technique. Step-by-step characterization of surface structure and reflectance of the MACE process is used after: 1) wafering, 2) standard acidic texturing etch, 3) silver nanoparticles deposition, and 4) MACE nanotexturing for both sc and mc-Si. The results show that the same MACE process works effectively for both sc-Si and mc-Si wafers. Finally, the nano-textured wafers are processed into PV cells in an industrial process line with conversion efficiencies of 19.4% and 18.7%, for sc-Si and mc-Si solar cells, respectively

A Novel Nicotinic Acetylcholine Receptor Subtype In Basal Forebrain Cholinergic Neurons With High Sensitivity To Amyloid Peptides

Nicotinic acetylcholine receptors (nAChRs) containing α7 subunits are thought to assemble as homomers. α7-nAChR function has been implicated in learning and memory, and alterations of α7-nAChR have been found in patients with Alzheimer\u27s disease (AD). Here we report findings consistent with a novel, naturally occurring nAChR subtype in rodent, basal forebrain cholinergic neurons. In these cells, α7 subunits are coexpressed, colocalize, and coassemble with β2 subunit(s). Compared with homomeric α7-nAChRs from ventral tegmental area neurons, functional, presumably heteromeric α7β;2-nAChRs on cholinergic neurons freshly dissociated from medial septum/diagonal band (MS/DB) exhibit relatively slow kinetics of whole-cell current responses to nicotinic agonists and are more sensitive to the β;2 subunit-containing nAChR-selective antagonist, dihydro-β- erythroidine (DHβE). Interestingly, presumed, heteromeric α7β2-nAChRs are highly sensitive to functional inhibition by pathologically relevant concentrations of oligomeric, but not monomeric or fibrillar, forms of amyloid β1-42 (Aβ1-42). Slow whole-cell current kinetics, sensitivity to DHβE, and specific antagonism by oligomeric Aβ1-42 also are characteristics of heteromeric α7β2-nAChRs, but not of homomeric α7-nAChRs, heterologously expressed in Xenopus oocytes. Moreover, choline-induced currents have faster kinetics and less sensitivity to Aβ when elicited from MS/DB neurons derived from nAChR β2 subunit knock-out mice rather than from wild-type mice. The presence of novel, functional, heteromeric α7β2-nAChRs on basal forebrain cholinergic neurons and their high sensitivity to blockade by low concentrations of oligomeric Aβ1-42 suggests possible mechanisms for deficits in cholinergic signaling that could occur early in the etiopathogenesis of AD and might be targeted by disease therapies. Copyright © 2009 Society for Neuroscience