A review of taxonomic research on Chinese wild grapes

The taxonomy of Chinese wild grapes can be traced back to the end of the 18th century. However, most research in this field was performed in the last three decades. On the basis of the data from the Chinese wild grape germplasm collected in the last 25 years at the College of Horticulture, Northwest A&F University, Yangling, Shaanxi, China, and publications by other scientists in China, we concluded there were 40 species, 1 subspecies, and 13 varieties of Chinese wild grapes. These were classified into 1 subgenus, 5 sections and 4 series according to FASONG WANG et al.’s systematics. The systematics on Chinese wild grapes is discussed in this paper.

The eco-geographic distribution of wild grape germplasm in China

Chinese wild Vitis species are mainly distributed in four major eco-geographic regions: (1) The Changbaishan Mountains and Xiaoxing’anling Mountains Region, (2) The Qinling Mountains Region, (3) The Mid-downstream Yangtze River Region and (4) The Guangxi Region. One, eighteen, thirty-two, and thirteen Vitis species have been found in these four regions, respectively. The Qinling Montains, the Bashan Montains, and the provinces of Jinagxi, Hubei, Hunan, and Guangxi have high Vitis diversity totaling over 30 species, indicating that these regions may be a major center of origin for Vitis. The range of distribution varies much among the species: Vitis pentagona, Vitis flexuosa, Vitis davidii, and Vitis wilsonae have a wide eco-geographic distribution; Vitis hancockii, Vitis bellula, and Vitis sinocinerea distribute more narrowly. The wild Vitis species of China are differentiated and adapted to local climates. We hope that this review familiarizes more researchers with the distribution of the wild grapes of China and will lead to more efficient collection and informed development of this germplasm.

Simple sequence repeat (SSR)-based diversity analysis of groundnut (Arachis hypogaea L.) germplasm resistant to bacterial wilt

Groundnut is one of the most important oilseed crops in the world. Bacterial wilt, caused by Ralstonia solanacearum E. F. Smith, is one of the major biotic constraints to groundnut production particularly in South-East Asia and East Africa. Several sources of resistance to bacterial wilt have been identified through field screening of groundnut germplasm. The aim of the present study was to quantify the genetic diversity among selected bacterial wilt-resistant lines, in comparison with the levels of variation observable within the cultivated A. hypogaea gene pool. Thirty-two SSR markers were used to assess the degree of molecular polymorphism between 46 selected genotypes revealing 107 alleles, of which 101 (99.4%) were polymorphic with gene diversity scores ranging from 0.103 to 0.669, averaging 0.386. Cluster and multidimensional scaling analysis revealed two distinct groups within the germplasm broadly corresponding to the two subspecies (hypogaea and fastigiata) of A. hypogaea. However, accessions of varieties peruviana and aequatoriana grouped together with the varieties from subsp. hypogaea, rather than grouping with the other varieties of subsp. fastigiata. Analysis of molecular variance (AMOVA) revealed that 15% of the total observed variation was accounted for by disease response groups. This analysis will be useful in the selection of parental genotypes for mapping populations and breeding programmes attempting to broaden the genetic base of future groundnut cultivars. In particular, this opens up significant opportunities for the development of intraspecific mapping populations that will be highly relevant to modern groundnut breeding programmes

A Novel OxyR Sensor and Regulator of Hydrogen Peroxide Stress with One Cysteine Residue in Deinococcus radiodurans

In bacteria, OxyR is a peroxide sensor and transcription regulator, which can sense the presence of reactive oxygen species and induce antioxidant system. When the cells are exposed to H2O2, OxyR protein is activated via the formation of a disulfide bond between the two conserved cysteine residues (C199 and C208). In Deinococcus radiodurans, a previously unreported special characteristic of DrOxyR (DR0615) is found with only one conserved cysteine. dr0615 gene mutant is hypersensitive to H2O2, but only a little to ionizing radiation. Site-directed mutagenesis and subsequent in vivo functional analyses revealed that the conserved cysteine (C210) is necessary for sensing H2O2, but its mutation did not alter the binding characteristics of OxyR on DNA. Under oxidant stress, DrOxyR is oxidized to sulfenic acid form, which can be reduced by reducing reagents. In addition, quantitative real-time PCR and global transcription profile results showed that OxyR is not only a transcriptional activator (e.g., katE, drb0125), but also a transcriptional repressor (e.g., dps, mntH). Because OxyR regulates Mn and Fe ion transporter genes, Mn/Fe ion ratio is changed in dr0615 mutant, suggesting that the genes involved in Mn/Fe ion homeostasis, and the genes involved in antioxidant mechanism are highly cooperative under extremely oxidant stress. In conclusion, these findings expand the OxyR family, which could be divided into two classes: typical 2-Cys OxyR and 1-Cys OxyR

Surveying the Down syndrome mouse model resource identifies critical regions responsible for chronic otitis media

Chronic otitis media (OM) is common in Down syndrome (DS), but underlying aetiology is unclear. We analysed the entire available mouse resource of partial trisomy models of DS looking for histological evidence of chronic middle-ear inflammation. We found a highly penetrant OM in the Dp(16)1Yey mouse, which carries a complete trisomy of MMU16. No OM was found in the Dp(17)1Yey mouse or the Dp(10)1Yey mouse, suggesting disease loci are located only on MMU16. The Ts1Cje, Ts1RhR, Ts2Yah, and Ts65Dn trisomies and the transchomosomic Tc1 mouse did not develop OM. On the basis of these findings, we propose a two-locus model for chronic middle-ear inflammation in DS, based upon epistasis of the regions of HSA21 not in trisomy in the Tc1 mouse. We also conclude that environmental factors likely play an important role in disease onset

Calmodulin kinase and a calmodulin-binding ‘IQ’ domain facilitate L-type Ca2+ current in rabbit ventricular myocytes by a common mechanism

Ca2+–calmodulin-dependent protein kinase II (CaMK) and a calmodulin (CaM)-binding ‘IQ’ domain (IQ) are both implicated in Ca2+-dependent regulation of L-type Ca2+ current (ICa). We used an IQ-mimetic peptide (IQmp), under conditions in which CaMK activity was controlled, to test the relationship between these CaM-activated signalling elements in the regulation of L-type Ca2+ channels (LTCCs) and ICa in rabbit ventricular myocytes.A specific CaMK inhibitory peptide nearly abolished ICa facilitation, but the facilitation was ‘rescued’ by cell dialysis with IQmp.IQmp significantly enhanced ICa facilitation and slowed the fast component of ICa inactivation, compared with an inactive control peptide. Neither effect could be elicited by a more avid CaM-binding peptide, suggesting that generalized CaM buffering did not account for the effects of IQmp.ICa facilitation was abolished and the fast component of inactivation eliminated by ryanodine, caffeine or thapsigargin, suggesting that the sarcoplasmic reticulum (SR) is an important source of Ca2+ for ICa facilitation and inactivation. IQmp did not restore ICa facilitation under these conditions.Engineered Ca2+-independent CaMK and IQmp each markedly increased LTCC open probability (Po) in excised cell membrane patches. The LTCC Po increases with CaMK and IQmp were non-additive, suggesting that CaMK and IQmp are components of a shared signalling pathway.Both CaMK and IQmp induced a modal gating shift in LTCCs that favoured prolonged openings, indicating that CaMK and IQmp affect LTCCs through a common biophysical mechanism.These findings support the hypothesis that CaMK is required for physiological ICa facilitation in cardiac myocytes. Both CaMK and IQmp were able to induce a modal gating shift in LTCCs, suggesting that each of these signalling elements is important for Ca2+-CaM-dependent LTCC facilitation in cardiac myocytes

Fractal Analytical Solutions for Nonlinear Two-Phase Flow in Discontinuous Shale Gas Reservoir

The paths of a two-phase flow are usually non-linear and discontinuous in the production of shale gas development. To research the influence mechanism between shale gas and water, several integer two-phase flow models have been studied but few analytical solutions have been obtained on shale gas and water pressure. This study first developed a local fractional mathematical model for gas and water two-phase flow in shale gas production. The model thus created considers the effects of capillary pressure, the fractal dimension of the flow pipe, and the discontinuity of the flow path. Second, the local fractional traveling wave method and variational iteration method were applied to this model for the development of iterative analytical solutions. Both shale gas and water pressure were analytically derived. Third, the depressurization process of the shale gas and water was analyzed, and a parametric study was conducted to explore the impacts of fractional dimension, entry capillary pressure, and travel wave velocity on shale gas pressure. Finally, our conclusions are drawn, based on the results of these studies

Fractal Analytical Solutions for Nonlinear Two-Phase Flow in Discontinuous Shale Gas Reservoir

The paths of a two-phase flow are usually non-linear and discontinuous in the production of shale gas development. To research the influence mechanism between shale gas and water, several integer two-phase flow models have been studied but few analytical solutions have been obtained on shale gas and water pressure. This study first developed a local fractional mathematical model for gas and water two-phase flow in shale gas production. The model thus created considers the effects of capillary pressure, the fractal dimension of the flow pipe, and the discontinuity of the flow path. Second, the local fractional traveling wave method and variational iteration method were applied to this model for the development of iterative analytical solutions. Both shale gas and water pressure were analytically derived. Third, the depressurization process of the shale gas and water was analyzed, and a parametric study was conducted to explore the impacts of fractional dimension, entry capillary pressure, and travel wave velocity on shale gas pressure. Finally, our conclusions are drawn, based on the results of these studies