Zamoralamb6289

Different plant hormones are involved in plant adaptation to water deficit. In comparison to angiosperms, little is known about the impact of drought on the pool of phytohormones in gymnosperms. Therefore, we studied the effect of polyethylene glycol-induced water deficit on the changes in content of different phytohormones in Scots pine and Norway spruce seedlings, which are known for their different strategies of adaptation to water deficit. The following hormone classes were analysed cytokinins, auxins, jasmonates, salicylic and benzoic acids, and 1-aminocyclopropane-1-carboxylic acid (an ethylene precursor). No consistent reaction to water stress was observed for the content of well-known stress-related hormones - salicylic acid and jasmonates. In contrast, drought induced a dose-dependent accumulation of cytokinins in pine needles, with less profound changes in spruce needles. The most prominent changes were observed for 1-aminocyclopropane-1-carboxylic acid content, which increased several-fold in spruce roots and pine needles under water deficit. Water-deficit-induced changes in the contents of cytokinins and 1-aminocyclopropane-1-carboxylic acid were accompanied by the differential regulation of genes involved in the metabolism of these hormones. Possible links between changes in hormone pools and the adaptation of seedlings to water deficit are discussed. Chenopodium quinoa, a halophytic crop belonging to the Amaranthaceae, has remarkable resistance to harsh growth conditions and produces seed with excellent nutritional value. This makes it a suitable crop for marginal soils. However, to date most of the commercial cultivars are susceptible to preharvest sprouting (PHS). Meanwhile, understanding of the PHS regulatory mechanisms is still limited. Abscisic acid (ABA) has been demonstrated to be tightly associated with seed dormancy and germination regulation in many crops. Whether ABA metabolism pathway could be manipulated to prevent PHS in quinoa is worth investigating. In the present study, we tested the inhibitory effects of exogenous ABA on quinoa seed germination. By RNA-seq analysis we investigated the global gene expression changes during seed germination, and obtained 1066 ABA-repressed and 392 ABA-induced genes. Cis-elements enrichment analysis indicated that the promoters of these genes were highly enriched in motifs "AAAAAAAA" and "ACGTGKC (K = G/T)", the specific binding motifs of ABI3/VP1 and ABI5. Transcription factor annotation showed that 13 genes in bHLH, MADS-box, G2-like and NF-YB, and five genes in B3, bZIP, GATA and LBD families were specifically ABA-repressed and -induced, respectively. Furthermore, expression levels of 53 key homologs involved in seed dormancy and germination regulation were markedly changed. Hence, we speculated that the 18 transcription factors and the homologs were potential candidates involved in ABA-mediated seed dormancy and germination regulation, which could be manipulated for molecular breeding of quinoa elites with PHS tolerance in future. Acetohydroxyacid synthase (AHAS, E.C. 2.2.1.6) is the target site of several herbicide classes including imidazolinones. Imidazolinone resistance in wheat is conferred by two major genes AhasL-D1 and AhasL-B1. The objective of this work was to evaluate the in vitro and in vivo AHAS activity and plant growth in response to imazamox of nine wheat cultivars. Dose-response curves for two-gene resistant cultivars were significantly different from the single-gene resistant and susceptible cultivars in the in vitro AHAS assay. Resistance levels at the in vivo AHAS and whole-plant assays for resistant cultivars were >10-fold higher than susceptible cultivars. MC903 concentration Moreover, in vivo dose-response curves showed differences among cultivars with the same number of resistance genes. It was concluded that in the in vitro AHAS assay cultivar variability was due to differences in target-site sensitivity while the in vivo AHAS assay reflected the resistance at whole-plant level. Both in vitro and in vivo AHAS dose-response curves could be useful tools when exploring mechanisms involved in imidazolinone resistance in different wheat genetic backgrounds and for the selection of higher resistant genotypes. Potassium (K+) has been reported to alleviate ammonium (NH4+) toxicity in rice through some underlying mechanisms, but it still not clear. In addition, K+ is an important cation for activation of plasma membrane (PM) H+-ATPase activity. Here, we hypothesized that K+ alleviated NH4+ toxicity by mediating PM H+-ATPase function in rice root. In this study, rice plants were cultivated in hydroponic solution with various concentrations of K+ and NH4+. By concurrently supplying K+ with NH4+ or re-supplying K+ after NH4+ toxicity, we found that high K+ concentration reduced the NH4+ uptake rate, enhanced the H+ extrusion rate by the roots, and alleviated rice NH4+ toxicity. The gene expression levels of PM H+-ATPase members (OsA1, 3, 7, 8, and 9) were upregulated by application of increasing concentrations of K+ under NH4+ toxicity. The PM H+-ATPase activity and protein expression in rice roots were also enhanced. Furthermore, the enhancement of PM H+-ATPase activity by a specific stimulator (fusicoccin) rescued rice seedlings from NH4+ toxicity. Taken together, these results indicate that K+ can alleviate NH4+ toxicity, possibly by activating PM H+-ATPase to extrude more H+ and inhibit NH4+ uptake by root. Our results may enhance understanding of the strategy of applying K+ fertilizer to mitigate crop NH4+ toxicity in agriculture. Caffeate 3-O-methyltransferase (COMT) catalyzes the methylation of the 3-hydroxyl group of caffeate to produce ferulate, an important precursor of the lignin biosynthesis. As a crucial drawback for biofuel production, lignin limits the enzymatic hydrolysis of polysaccharides to result in fermentable sugars. link2 We hypothesized that a controlled inhibition of maize COMT can be an efficient approach to reduce ferulate and lignin, thus improving the saccharification process. First, we applied in silico techniques to prospect potential inhibitors of ZmaysCOMT, and the nitrocatechol entacapone was selected. Second, in vitro assays confirmed the inhibitory effect of entacapone on maize COMT. Finally, in vivo experiments revealed that entacapone reduced the contents of cell-wall-esterified hydroxycinnamates and increased saccharification of stems (18%) and leaves (70%), without negatively affecting maize growth and lignin biosynthesis. This non-genetically modified approach can be an alternative strategy to facilitate the enzymatic hydrolysis of biomass polysaccharides and increase saccharification for bioethanol production. OBJECTIVES Supplementation provides the best means of improving vitamin D status; however, individual responses vary partly owing to genetics. The aim of this study was to determine whether 28 single nucleotide polymorphisms (SNPs) in six key vitamin D pathway genes (GC, DHCR7, CYP2 R1, CYP24 A1, CYP27 B1, VDR) were associated with differences in response to supplementation. METHODS Participants (N = 313; n = 160 vitamin D, n = 153 placebo) were part of VIDARIS (Vitamin D and Acute Respiratory Infections Study), a double-blind, randomized controlled trial involving oral monthly supplementation of either vitamin D3 (200 000 IU each for the first 2 mo, thereafter 100 000 IU monthly) or placebo for 18 mo. link3 Circulating 25-hydroxyvitamin D (25[OH]D) concentrations at baseline and 2, 6, 12, and 18 mo, and vitamin D binding protein (Gc-globulin) and calculated free 25(OH)D concentrations at baseline and 2 mo were obtained. Multiple regression was used to model associations between genetic variants and 25(OH)D, Gc-globulin, and free 25(OH)D concentrations. RESULTS SNPs within GC, CYP2 R1, and CYP27 B1 were associated with 25(OH)D concentrations following supplementation. However, only two GC gene SNPs (rs2282679, rs1155563) were significant after adjustment for multiple testing. This effect disappeared after more than 2 mo of supplementation. None of the SNPs were significantly associated with Gc-globulin concentrations; however, there was a significant interaction with one SNP in DHCR7 (rs12785878), which was associated with reduced free 25(OH)D concentrations in the supplemented arm. CONCLUSION Only variants of GC were associated with 25(OH)D concentrations after supplementation. This effect was modest and disappeared after >2 mo of supplementation, suggesting it may be time/dose-dependent and saturable. The ethoxylated isomers of nonylphenol (NPEs, NP-9) are one of the main active ingredients present in nonionic surfactants employed as herbicides, cosmetics, paints, plastics, disinfectants and detergents. These chemicals and their metabolites are commonly found in environmental matrices. The aim of this work was to evaluate the intergenerational toxicity of NP-9 in Caenorhabditis elegans. The lethality, length, width, locomotion and lifespan were investigated in the larval stage L4 of the wild strain N2. Transgenic green fluorescent protein (GFP) strains were employed to estimate changes in relative gene expression. RT-qPCR was utilized to measure mRNA expression for neurotoxicity-related genes (unc-30, unc-25, dop-3, dat-1, mgl-1, and eat-4). Data were obtained from parent worms (P0) and the first generation (F1). Lethality of the nematode was concentration-dependent, with 48 h-LC50 values of 3215 and 1983 μM in P0 and F1, respectively. Non-lethal concentrations of NP-9 reduced locomotion. Lifespan was also decreased by the xenobiotic, but the negative effect was greater in P0 than in F1. Non-monotonic concentration-response curves were observed for body length and width in both generations. The gene expression profile in P0 was different from that registered in F1, although the expression of sod-4, hsp-70, gpx-6 and mtl-2 increased with the surfactant concentration in both generations. None of the tested genes followed a classical concentration-neurotoxicity relationship. In P0, dopamine presented an inverted-U curve, while GABA and glutamate displayed a bimodal type. However, in F1, inverted U-shaped curves were revealed for these genes. In summary, NP-9 induced intergenerational responses in C. elegans through mechanisms involving ROS, and alterations of the GABA, glutamate, and dopamine pathways. Cadmium (Cd) contamination in agricultural soil is a worldwide environmental problem. In situ stabilization has been considered an effective approach for the remediation of Cd-contaminated agricultural soil. However, information about the long-term effects of amendment on soil properties and stabilization efficiency remains limited. In the present study, mercapto-functionalized nano-silica (MPTS/nano-silica) was used to stabilize Cd in contaminated agricultural soil under field conditions for three years (with application rates of 0%, 0.2%, 0.4%, 0.6%, 0.8% and 1.0%). The application of MPTS/nano-silica reduced the soil aggregate stability (PDA0.25) (14.8%) and available K (24.9%) and significantly increased the soil dehydrogenase (DHA) (43.4%), yield of wheat grains (33.5%) and Si content in wheat tissues (55.2% in leaf, 50.4% in stem, and 37.7% in husk) (p  less then  0.05). More importantly, MPTS/nano-silica decreased the leachability (36.0%) and bioavailability (54.3%) of Cd in the soil and transformed Cd into a more stable fraction.