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Tissue specificity of the sugarcane bacilliform virus promoter in oat,barley and wheat 总被引:1,自引:0,他引:1
Al-Saady Nadiya A. Torbert Kimberly A. Smith Lisa Makarevitch Irina Baldridge Gerald Zeyen Richard J. Muehlbauer Gary J. Olszewski Neil E. Somers David A. 《Molecular breeding : new strategies in plant improvement》2004,14(3):331-338
The tissue-specificity of the sugarcane bacilliform virus (SCBV) promoter was investigated in oat, barley, and wheat to determine whether its expression pattern in one species was predictive of promoter specificity in the other closely related Gramineae species. Progeny of transgenic plants produced using constructs containing the SCBV promoter driving gusA were sampled at different stages of plant development and stained for GUS activity using a histochemical assay. Overall, the GUS staining patterns were most similar between oat and barley. In all three species, similar GUS staining patterns were observed in mature endosperms, leaves, and floral bracts of developing infloresences. No GUS staining was detected in oat embryos whereas the entire barley embryo was stained, and GUS staining was confined to the scutellum of wheat embryos. Oat and barley stems exhibited GUS staining whereas no GUS staining was observed in stems of the transgenic wheat plants. The SCBV promoter conferred strong GUS staining intensity in most tissues of oat and barley but was generally weaker in wheat. These differences in SCBV promoter specificity indicate that promoter evaluation should be conducted in the target species of interest rather than by extrapolation from expression patterns in other species. 相似文献
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Overexpression of the maize Teosinte Branched1 gene in wheat suppresses tiller development 总被引:1,自引:0,他引:1
Lewis JM Mackintosh CA Shin S Gilding E Kravchenko S Baldridge G Zeyen R Muehlbauer GJ 《Plant cell reports》2008,27(7):1217-1225
The number of viable shoots influences the overall architecture and productivity of wheat (Triticum aestivum L.). The development of lateral branches, or tillers, largely determines the resultant canopy. Tillers develop from the outgrowth of axillary buds, which form in leaf axils at the crown of the plant. Tiller number can be reduced if axillary buds are not formed or if the outgrowth of these buds is restricted. The teosinte branched1 (tb1) gene in maize, and homologs in rice and Arabidopsis, genetically regulate vegetative branching. In maize, increased expression of the tb1 gene restricts the outgrowth of axillary buds into lateral branches. In this study, the maize tb1 gene was introduced through transformation into the wheat cultivar "Bobwhite" to determine the effect of tb1 overexpression on wheat shoot architecture. Examination of multiple generations of plants reveals that tb1 overexpression in wheat results in reduced tiller and spike number. In addition, the number of spikelets on the spike and leaf number were significantly greater in tb1-expressing plants, and the height of these plants was also reduced. These data reveal that the function of the tb1 gene and genetic regulation of lateral branching via the tb1 mode of action is conserved between wheat, rice, maize and Arabidopsis. Thus, the tb1 gene can be used to alter plant architecture in agriculturally important crops like wheat. 相似文献
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Transgenic wheat expressing a barley class II chitinase gene has enhanced resistance against Fusarium graminearum 总被引:1,自引:0,他引:1
Shin S Mackintosh CA Lewis J Heinen SJ Radmer L Dill-Macky R Baldridge GD Zeyen RJ Muehlbauer GJ 《Journal of experimental botany》2008,59(9):2371-2378
Fusarium head blight (FHB; scab), primarily caused by Fusarium graminearum, is a devastating disease of wheat worldwide. FHB causes yield reductions and contamination of grains with trichothecene mycotoxins such as deoxynivalenol (DON). The genetic variation in existing wheat germplasm pools for FHB resistance is low and may not provide sufficient resistance to develop cultivars through traditional breeding approaches. Thus, genetic engineering provides an additional approach to enhance FHB resistance. The objectives of this study were to develop transgenic wheat expressing a barley class II chitinase and to test the transgenic lines against F. graminearum infection under greenhouse and field conditions. A barley class II chitinase gene was introduced into the spring wheat cultivar, Bobwhite, by biolistic bombardment. Seven transgenic lines were identified that expressed the chitinase transgene and exhibited enhanced Type II resistance in the greenhouse evaluations. These seven transgenic lines were tested under field conditions for percentage FHB severity, percentage visually scabby kernels (VSK), and DON accumulation. Two lines (C8 and C17) that exhibited high chitinase protein levels also showed reduced FHB severity and VSK compared to Bobwhite. One of the lines (C8) also exhibited reduced DON concentration compared with Bobwhite. These results showed that transgenic wheat expressing a barley class II chitinase exhibited enhanced resistance against F. graminearum in greenhouse and field conditions. 相似文献
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The serum fructosamine concentration indicates the degree of glycation of serum proteins, particularly albumin, and reflects an average blood glucose level over the previous 1-3 weeks. Serum fructosamine, glycated haemoglobin (HbA1c), total serum protein, serum albumin, fasting plasma glucose and oral glucose tolerance test (OGTT) have been measured in 127 healthy control subjects, 102 type 1 and 152 type 2 diabetes mellitus patients and 106 nondiabetic pregnant women. Fructosamine concentration of 2.24 +/- 0.16 and 3.21 +/- 0.41 mmol/l (mean +/- S.D.) has been found in control subjects and diabetics respectively (P less than 0.001). During the second trimester a significantly lower fructosamine level (1.92 +/- 0.21 mmol/l) has been found in pregnant women, most likely due to the low serum albumin concentration (31.35 +/- 3.97 g/l). None of them had a fructosamine level above the normal limit of 2.55 mmol/l. On the other hand, 12 pregnant women showed a disturbed OGTT with normal fructosamine. If the serum fructosamine concentration was adjusted for 40 g/l albumin, then a mean fructosamine of 2.16 +/- 0.24 mmol/l was found in patients with gestational diabetes. Our results show that serum fructosamine has a similar diagnostic value as HbA1c for non-pregnant adults, but neither can replace OGTT for the diagnosis of gestational diabetes. 相似文献
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Overexpression of defense response genes in transgenic wheat enhances resistance to Fusarium head blight 总被引:2,自引:0,他引:2
Mackintosh CA Lewis J Radmer LE Shin S Heinen SJ Smith LA Wyckoff MN Dill-Macky R Evans CK Kravchenko S Baldridge GD Zeyen RJ Muehlbauer GJ 《Plant cell reports》2007,26(4):479-488
Fusarium head blight (FHB) of wheat, caused by Fusarium graminearum and other Fusarium species, is a major disease problem for wheat production worldwide. To combat this problem, large-scale
breeding efforts have been established. Although progress has been made through standard breeding approaches, the level of
resistance attained is insufficient to withstand epidemic conditions. Genetic engineering provides an alternative approach
to enhance the level of resistance. Many defense response genes are induced in wheat during F. graminearum infection and may play a role in reducing FHB. The objectives of this study were (1) to develop transgenic wheat overexpressing
the defense response genes α-1-purothionin, thaumatin-like protein 1 (tlp-1), and β-1,3-glucanase; and (2) to test the resultant
transgenic wheat lines against F. graminearum infection under greenhouse and field conditions. Using the wheat cultivar Bobwhite, we developed one, two, and four lines
carrying the α-1-purothionin, tlp-1, and β-1,3-glucanase transgenes, respectively, that had statistically significant reductions
in FHB severity in greenhouse evaluations. We tested these seven transgenic lines under field conditions for percent FHB disease
severity, deoxynivalenol (DON) mycotoxin accumulation, and percent visually scabby kernels (VSK). Six of the seven lines differed
from the nontransgenic parental Bobwhite line for at least one of the disease traits. A β-1,3-glucanase transgenic line had
enhanced resistance, showing lower FHB severity, DON concentration, and percent VSK compared to Bobwhite. Taken together,
the results showed that overexpression of defense response genes in wheat could enhance the FHB resistance in both greenhouse
and field conditions. 相似文献
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Damian Dalcher Jennifer Yihong Tan Cristiana Bersaglieri Rodrigo PeaHernndez Eva Vollenweider Stefan Zeyen Marc W Schmid Valerio Bianchi Stefan Butz Marcin Roganowicz Rostyslav Kuzyakiv Tuncay Baubec Ana Claudia Marques Raffaella Santoro 《The EMBO journal》2020,39(23)
Chromosomes have an intrinsic tendency to segregate into compartments, forming long‐distance contacts between loci of similar chromatin states. How genome compartmentalization is regulated remains elusive. Here, comparison of mouse ground‐state embryonic stem cells (ESCs) characterized by open and active chromatin, and advanced serum ESCs with a more closed and repressed genome, reveals distinct regulation of their genome organization due to differential dependency on BAZ2A/TIP5, a component of the chromatin remodeling complex NoRC. On ESC chromatin, BAZ2A interacts with SNF2H, DNA topoisomerase 2A (TOP2A) and cohesin. BAZ2A associates with chromatin sub‐domains within the active A compartment, which intersect through long‐range contacts. We found that ground‐state chromatin selectively requires BAZ2A to limit the invasion of active domains into repressive compartments. BAZ2A depletion increases chromatin accessibility at B compartments. Furthermore, BAZ2A regulates H3K27me3 genome occupancy in a TOP2A‐dependent manner. Finally, ground‐state ESCs require BAZ2A for growth, differentiation, and correct expression of developmental genes. Our results uncover the propensity of open chromatin domains to invade repressive domains, which is counteracted by chromatin remodeling to establish genome partitioning and preserve cell identity. 相似文献
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