RESUMO
Phyllosticta (Phyllostictaceae, Botryosphaeriales) species are widely distributed globally and constitute a diverse group of pathogenic and endophytic fungi associated with a broad range of plant hosts. In this study, four new species of Phyllosticta, i.e. P. endophytica, P. jiangxiensis, P. machili, and P. xinyuensis, were described using morphological characteristics and multi-locus phylogeny based on the internal transcribed spacer region (ITS) with intervening 5.8S rRNA gene, large subunit of rRNA gene (nrLSU), translation elongation factor 1-alpha gene (tef1), actin gene (act), and glyceraldehyde-3-phosphate dehydrogenase gene (gapdh). Phyllosticta machili is the first species of this genus reported to infect plants of the Machilus genus.
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Nagrajomyces (incertae sedis, Ascomycota) is a monotypic genus with a previously unknown systematic position. In this report, two new species are proposed, Nagrajomycesfusiformis and Nagrajomyceslaojunshanensis. These new taxa are proposed based on morphological characteristics evident via light microscopy and molecular data. Multi-locus phylogenetic analyses (ITS rDNA, nrLSU rDNA, RPB2, and TEF1-α) show that specimens recently collected in Yunnan Province, China are closely related to Gnomoniaceae. Both new species and known species were discovered repeatedly in their asexual developmental form exclusively on twigs of Rhododendron spp. (Ericaceae). This indicates a host specificity of Nagrajomyces spp. for species of Rhododendron.
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Species of the genus Russula are key components of ectomycorrhizal ecosystems worldwide, some of which are famous edible fungi. Although many new species have been described in China, their diversity in North China is still poorly known. Based on the morphology observation of specimens and molecular phylogenetic analyses, combined with the current classification frame of Russula, six new species of Russula subgenus Russula are proposed from the Yanshan Mountains in northern Beijing and northern Hebei Province of China in this study: viz. Russula miyunensis (subsection Chamaeleontinae), R. plana (subsection Chamaeleontinae), R. sinoparva (subsection Puellarinae), R. sinorobusta (subsection Puellarinae), R. subversatilis (subsection Roseinae), and R. yanshanensis (subsection Puellarinae). This is the first report of the species of Russula subgenus Russula from the Yanshan Mountains. This study enriches the species diversity of Russula in North China and provides new data support for the systematic study of Russula in subsequent research, including research and development on edibility.
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We aimed to determine whether humic acid (HA) can alleviate the injury of millet caused by drought and its potential mechanism. Millet seeds (Jingu 21 and Zhangza 10) were soaked in different concentrations of HA (0, 50, 10, 200, and 300 mg L-1) for 12 h. The physiological and photosynthetic characteristics of millet seedlings, including growth parameters, osmotic regulators, antioxidase activity, photosynthesis, chlorophyll fluorescence, and P700 parameters, were determined before and after drought stress. HA significantly promoted the growth of millet seedlings under drought stress. Pretreatment with 100 mg L-1 or 200 mg L-1 HA significantly increased free proline, soluble protein, and activity of the antioxidant enzyme system (superoxide dismutase, peroxidase, and catalase) in both Zhangza 10 and Jingu 21. The accumulation of reactive oxygen species ([Formula: see text] and H2O2) was reduced in HA treatments compared with that of the control (P < .05). Moreover, HA (100 mg L-1) significantly increased net photosynthetic rate, stomatal conductance, effective quantum yield of photosystem II, relative photosynthetic electron transfer rate of photosystem II, and photochemical quenching. HA also reduced intercellular CO2 concentration and non-photochemical quenching. Furthermore, 200 mg L-1 HA significantly increased the maximum P700, effective quantum yield of photosystem I, and relative photosynthetic electron transfer rate of photosystem I in Zhangza 10 and decreased non-photochemical energy dissipation in Jingu 21 and Zhangza 10 under drought stress. HA promoted the growth of millet seedlings under drought stress by promoting the osmotic adjustment ability and antioxidant capacity of seedlings and increased photosynthesis.
Assuntos
Secas , Substâncias Húmicas , Milhetes/metabolismo , Milhetes/fisiologia , Fotossíntese/fisiologia , Plântula/metabolismo , Plântula/fisiologia , Espécies Reativas de Oxigênio/metabolismoRESUMO
Although addition of selenium (Se) is known to increase Se in crops, it is unclear whether exogenous Se is linked to nutritional and functional components in foxtail millet (Setaria italica L.). In this study, we examined the potential of increasing Se and yellow pigment (YP) in foxtail millet grain by foliar application of Se. Field experiments were conducted during the growing season of foxtail millet in 2013 and 2014 to assess the effects of foliar spray of sodium selenite (10-210 g Se ha(-1)) on the yield, Se uptake and accumulation, total YP, and microminerals in the grain. Average grain yields with Se application were 5.60 and 4.53 t ha(-1) in the 2 years, showing no significant differences from the unfertilized control. However, grain Se concentration increased linearly with Se application rate, by 8.92 and 6.09 µg kg(-1) in the 2 years with application of 1 g Se ha(-1) (maximum grain recovery rates of Se fertilizer, 52 and 28 %). Likewise, total grain YP concentration markedly increased by 0.038 and 0.031 mg kg(-1) in the 2 years with application of 1 g Se ha(-1). Grain Mn, Cu, Fe, and Zn concentrations were not significantly affected by Se application. This study indicated that foliar application of Se effectively and reliably increased the concentrations of Se and YP in foxtail millet grain without affecting the yield or mineral micronutrient concentrations. Thus, foliar-applied selenite has a significant potential to increase the concentrations of selenium and YP (putative lutein (Shen, J Cereal Sci 61:86-93, 2015; Abdel-Aal, Cereal Chem 79:455-457, 2002; Abdel-Aal, J Agric Food Chem 55:787-794, 2007)) of foxtail millet and, thus, the health benefits of this crop.
Assuntos
Milhetes/metabolismo , Pigmentos Biológicos/metabolismo , Ácido Selenioso/administração & dosagem , Selênio/metabolismo , Folhas de Planta/metabolismoRESUMO
Four novel Zn(II) complexes [Zn(L(1))(bipy)(H(2)O)(2)].4H(2)O(1), [Zn(L(1))(phen)(H(2)O)(2)].4H(2)O(2), [Zn(L(2))(bipy)(H(2)O)(2)].4H(2)O(3) and [Zn(L(2))(phen)(H(2)O)(2)].4H(2)O (4), where bipy=2,2'-bipyridine, phen=1,10-phenanthroline, L(1)=2,2'-bipyridine 5,5'-dicarboxylic acid, L(2)=2,2'-bipyridine-4,4'-dicarboxylic acid, have been synthesized and characterized using IR, (1)H NMR, element analysis and single-crystal X-ray diffractometry. The unit cell parameters for the title complex (1), a=7.9621(10)A, b=12.6853(17)A, c=13.3714(17)A, alpha=68.549(2) degrees , beta=79.065(2) degrees , gamma=88.723(2) degrees , V=1232.5(3)A(3), Z=15, space group,P-1(2).complex (4) a=9.5710(5)A, b=14.1140(7)A, c=19.0045(9)A, alpha=90 degrees , beta=99.9920(10) degrees , gamma=90 degrees , V=2528.3(2)A(3), Z=32, space group, P121/n 1(14). The binding of the complexes with fish sperm DNA (FS-DNA) was investigated by electronic absorption spectra and fluorescence spectroscopy, showing that the complexes have the ability of interaction with DNA of intercalative mode. The intrinsic binding constant K of the complexes with FS-DNA is 0.37 x 10(5)M(-1) (1) 0.73 x 10(5)M(-1) (2), 0.98 x 10(5)M(-1) (3), and 1.05 x 10(5)M(-1) (4). The results indicate that the four complexes bound to DNA with different binding affinity, in the order complex 4>3>2>1. Gel electrophoresis assay demonstrates the ability of the complexes to cleave the pBR322 plasmid DNA. The cytotoxic activity of the complexes was tested against four different cancer cell lines. The four complexes exhibited cytotoxic specificity and significant cancer cell inhibitory rate.