Studies upon the copper fungicides: VII. The solution of copper from dressings on the pea seed

During the process of swelling pea seeds yielded substances to water which were capable of dissolving the insoluble copper dressings normally applied to the seed to prevent 'pre-emergence damping off'. This occurred under conditions in which soil factors were eliminated and irrespective of whether the dressing was on the surface of the seed or treated separately. Copper was readily taken into solution from dried 4:4:50 Bordeaux Mixture by water in which peas had been soaked, a circumstance which proved that the formation of soluble complex forms of copper was involved.
A chemical investigation on the solution obtained by soaking peas in water showed that volatile acids or their salts were present together with a protein-like material in colloidal solution. The occurrence of amino derivatives and other nitrogenous materials as well as carbohydrates was indicated and evidence of the presence of asparagine and citrate was also obtained.
The suggestion is made that both the fungicidal and phytocidal actions of insoluble copper dressings on pea seed depend largely on the effect of the pea seed exudates, notably colloidal protein-like material and certain amino derivatives, in bringing copper into solution.     

Interspersion of different repeated sequences in the wheat genome revealed by interspecies DNA/DNA hybridisation.

The repeated sequences in oats DNA have been used to study chromosomal repeated sequence organisation in wheat. Approximately 75% of the wheat genome consists of repeated sequences but only approximately 20% will form heteroduplexes with repeated sequences from oats DNA at 60 degrees C in 0.18 M Na+. The proportion of wheat DNA that forms heteroduplexes with oats DNA is shown to be independent of the wheat DNA fragment length. However, the proportion of wheat DNA that is retained with the heteroduplexes when fractionated on hydroxyapatite is very dependent upon the wheat fragment length up to 3500 nucleotides. This is because more non-renatured wheat DNA is attached to the heteroduplexes with longer fragments. The results indicate that the repeated sequences in the wheat genome homologous to repeated sequences in oats are not clustered in the chromosomes but distributed amongst other repeated and possible non-repeated sequences.     

Influence of volunteer wheat plant condition on movement of the wheat curl mite, Aceria tosichella, in winter wheat

The wheat curl mite (WCM), Aceria tosichella Keifer, is the vector of wheat streak mosaic virus and high plains virus which cause significant crop loss in winter wheat throughout the western Great Plains. Volunteer wheat emerging before harvest, as a result of severe hail, is the primary source of mites and virus that infect fall-planted winter wheat. Wind-borne movement of the WCM is of key importance in the spread and infection of the virus complex. Significant movement of WCM from wheat has been thought to be closely tied to the senescence or deterioration of the host. Results from field and greenhouse studies indicated that movement from un-vernalized winter wheat was not closely associated with the deterioration of the wheat host. Greenhouse studies showed no correlation between WCM movement and plant condition, but there was a highly significant relationship between WCM movement and mite population on the host plant. Field studies did not demonstrate increased movement associated with deteriorating un-vernalized winter wheat. However, healthier hosts which were able to support a larger population of mites were associated with increased movement. The main influence on the level of mite movement relates to the size of the source population and not the condition of the host plant, but plant condition appears to be a factor in limiting the increase of the WCM population.     

A type 1 diabetes-related protein from wheat (Triticum aestivum). cDNA clone of a wheat storage globulin,Glb1, linked to islet damage

The development of autoimmune type 1 diabetes involves complex interactions among several genes and environmental agents. Human patients with type 1 diabetes show an unusually high frequency of wheat gluten-sensitive enteropathy; T-cell response to wheat proteins is increased in some patients, and high concentrations of wheat antibodies in blood have been reported. In both major models of spontaneous type 1 diabetes, the BioBreeding (BB) rat and non-obese diabetic mouse, at least half of the cases are diet-related. In studies of BB rats fed defined semipurified diets, wheat gluten was the most potent diabetes-inducing protein source. A major limitation in understanding how wheat or other dietary antigens affect type 1 diabetes has been the difficulty in identifying specific diabetes-related dietary proteins. To address this issue, we probed a wheat cDNA expression library with polyclonal IgG antibodies from diabetic BB rats. Three clones were identified, and the intensity of antibody binding to one of them, WP5212, was strongly associated with pancreatic islet inflammation and damage. The WP5212 putative protein has high amino acid sequence homology with a wheat storage globulin, Glb1. Serum IgG antibodies from diabetic rats and humans recognized low molecular mass (33-46 kDa) wheat proteins. Furthermore, antibodies to Glb1 protein were found in serum from diabetic patients but not in age-, sex-, and HLA-DQ-matched controls. This study raises the possibility that in some individuals, type 1 diabetes may be induced by wheat proteins. Also, it provides a first candidate wheat protein that is not only antigenic in diabetic rats and human patients but is also closely linked with the autoimmune attack in the pancreas.     

Brotgetreide

Bread cereals Wheat and spelt are primarily used as bread cereals together with rye. To increase the worldwide wheat production and achieve cultivation goals faster, the very large bread wheat genome is currently analyzed intensively. Wheat is hexaploid and contains three genomes side by side which do not hybridize. The progenitors of einkorn (diploid) and emmer (tetraploid) have been the ancestors of today's wheat and spelt. Spelt is less demanding than wheat but requires an extra stage of husk removal before milling. In Germany, spelt is nowadays a modern bread cereal again. As it has a higher ratio of essential amino acids, the protein part of rye is more valuable for nutrition than that of wheat. Climatic conditions as well as poorer soils in Northern Germany are more suitable for rye than for wheat. Therefore rye has been a typical German bread cereal since medieval times.     

雪花莲凝集素基因转化小麦及转基因小麦抗蚜性的研究

雪花莲凝集素对具有刺吸式口器的同翅目害虫具有毒杀作用。用基因枪法将1个新的雪花莲凝集素(GNA)基因转入普通春小麦品种中-60634和生产上正在推广的冬小麦高产品种——豫麦66中,分别获得了转基因小麦植株。抗蚜实验证明,转化gna基因的小麦植株对我国北方冬麦区的主要麦蚜——麦长管蚜和禾谷缢管蚜的抗性效果不尽相同。对禾谷缢管蚜,在接种当代即表现出明显的毒杀作用。对麦长管蚜,则表现为虫体发育减缓并且降低了其所生产的若蚜成活率。在自然放养条件下,gna基因则对这两种麦蚜的取食均起到了一定的抑制作用。     

Contents of a storage pit from late Bronze Age Stillfried,Austria: another record of the "new" glume wheat

Since Jones et al. (2000) drew attention to a "new" type of glume wheat from Neolithic and Bronze Age sites in northern Greece, several finds of this morphologically distinct tetraploid wheat form have been made across central and southeastern Europe. Charred remains of this wheat, dating from 819–1031 cal b.c., have also been discovered in a storage pit at late Bronze Age Stillfried, eastern Austria. As both chaff and grains were found, it was not only possible to match the diagnostic features of the spikelet bases to the "new" form, but also to examine the grains, which are strikingly long, slender and flat. A dorsal ridge is absent and there is no hump above the embryo. The embryo angle is relatively low and compression lines are much more distinct. Within the Stillfried store "new" glume wheat grains were also easily separable from two-grained einkorn and spelt grains. The morphology of the grains is not inconsistent with the suggestion that the "new" type glume wheat might correspond to modern Triticum timopheevi. In Stillfried "new" glume wheat was grown as a winter crop, and it seems to have been cultivated as a maslin (mixed crop) together with T. monococcum (einkorn).     

The inheritance of the traits of resistance to fungal diseases by distant hybrids of wheat with amphiploids

The inheritance of resistance to powdery mildew, leaf rust and septorios of hybrids from crosses of wheat--rye and two wheat--Elymus amphiploids with durum and bread wheat was studied. Spontaneous hybridization was revealed to be a determining factor of the new available trait formation in the wide crosses. Control of the leaf rust and heary leaf traits by the same alien chromosome of Elytricum fertile is confirmed. While in the wheat--Aegilops amphiploid H74/90-258 these traits are not linked and controlled by one and two genes, respectively. The alien resistance is easier introgessed into wheat genome in the cross of 8x-amphiploid with durum wheat, than with bread wheat. Constant homozygous strains with group resistance to the studied diseases have been revealed.     

Genetic engineering of wheat--current challenges and opportunities

Wheat is one of the major staple food crops grown worldwide; however, productivity in cereal crops has not kept pace with the world population growth. A significant increase in wheat production (>40% by 2020) is needed simply to keep up with the growing demand. This increase is unlikely to be achieved by conventional plant breeding methods because of the limited gene pool available. The application of recombinant techniques to improve wheat quality and yield is not only desirable but also has potential to open up new opportunities. Although there has been significant progress in developing gene-transformation technologies for improving these traits, this remains an important challenge for plant biotechnology. Obstacles to translate the full potential of the genomic era to wheat breeding include the need to develop elite wheat varieties without selectable markers, introducing minimal or nil intergenic DNA and social and market issues concerning genetically engineered food products.     

Agarose gel filtration of Triticum vulgare proteins in dissociating solvents

Certain wheat proteins (glutenins emerged from 4% agarose columns at the void volumes even in the presence of 6 M guanidine hydrochloride, 4 M urea with or without 1% sodium dodecyl sulphate, and 8 M urea. These proteins were of considerably greater molecular size than bovine thyroglobulin (sub-unit MW 335000). Urea plus sodium dodecyl sulphate was the most effective dissociating solvent. Low MW wheat flour proteins, which had been covalently labelled with a fluorescein derivative, were not incorporated through formation of new disulphide bonds into higher MW fractions during acidic extraction of flour. Limited incorporation through non-covalent association was observed. The results do not support the contention that glutenin is an artifact of extraction. It has been confirmed that all the protein of wheat flour is not extractable with water followed by 2 M urea.     

Role of proteolytic enzymes in the development of amino acid imbalance in wheat endosperm proteins

Three proteases with caseinolytic activity have been isolated from the developing wheat endosperm. Two have been purified. The activity of protease A, the one that appears early in endosperm development, is inhibited by - SH inhibitors. Protease C, the one that appears late in endosperm development, is not affected. Protease A cleaves polyaspartic acid and polyglutamic acid but not polylysine. Protease C, on the other hand, cleaves polylysine but not polyaspartic acid and polyglutamic acid. Protease C degrades lysine-rich proteins isolated from wheat endosperm more efficiently than protease A.     

Identification of Russian wheat aphid (Homoptera: Aphididae) populations virulent to the Dn4 resistance gene

The Russian wheat aphid, Diuraphis noxia (Mordvilko), is a serious worldwide pest of wheat and barley. Russian wheat aphid populations from Hungary, Russia, and Syria have previously been identified as virulent to D. noxia (Dn) 4, the gene in all Russian wheat aphid-resistant cultivars produced in Colorado. However, the virulence of Russian wheat aphid populations from central Europe, North Africa, and South America to existing Dn genes has not been assessed. Experiments with plants containing several different Dn genes demonstrated that populations from Chile, the Czech Republic, and Ethiopia are also virulent to Dn4. The Czech population was also virulent to plants containing the Dnx gene in wheat plant introduction PI220127. The Ethiopian population was also virulent to plants containing the Dny gene in the Russian wheat aphid-resistant 'Stanton' produced in Kansas. The Chilean and Ethiopian populations were unaffected by the antibiosis resistance in Dn4 plants. There were significantly more nymphs of the Chilean population on plants of Dn4 than on Dn6 plants at both 18 and 23 d postinfestation, and the Ethiopian population attained a significantly greater weight on Dn4 plants than on plants containing Dn5 or Dn6. These newly characterized virulent Russian wheat aphid populations pose a distinct threat to existing or proposed wheat cultivars possessing Dn4.     

宁夏国外小麦种质资源考察、引进和利用

国外小麦种质资源引进在宁夏小麦引种中发挥着重要的作用。碧玉麦、阿勃、墨卡(卡杰姆F-71)、WC-20(宁春37)、9186(宁冬6号)等国外小麦品种在宁夏生产上直接利用。宁夏春小麦的品质杂交选育始于1953年,利用国外小麦种质资源先后培育出斗地1号、宁春4号等50余个春麦品种。1990年宁夏国外冬麦种质资源的引进带动了宁夏引黄灌区冬麦北移和耕作改制的研究,也引发了宁夏冬麦品种杂交选育的研究。宁夏引黄灌区冬小麦品种的杂交选育的工作始于1991年,经过15年的努力,杂交选育出第一批冬麦品种宁冬10号、宁冬11号,2010年在冬麦生产上取代了明丰5088,不仅实现了宁夏引黄灌区冬小麦品种第3次更新、实现了小麦品种的5次更新,而且使宁夏小麦生产水平跃上新台阶,有力地促进宁夏引黄灌区耕作制度改善和种植业结构的调整。     

A novel protein programmed by the mRNA conserved in dry wheat embryos. The principal site of cysteine incorporation during early germination

If bulk mRNA from dry wheat embryos (wheat germ) is used to direct cell-free incorporation of [35S]cysteine into proteins, a striking proportion of the total radioactivity is channeled into a single protein. During early postimbibition development, when protein synthesis is directed by the mRNA conserved in dry embryos, incorporation of cysteine is preponderantly (20-25%) directed into synthesis of this one protein: the 'early' cysteine-labeled protein (Ec). When conserved mRNA from the dry embryos has been fully degraded, as when cellular or cell-free protein synthesis is directed by the mRNA in germinated embryos, synthesis of Ec is not detected. Reliable detection of Ec requires prior alkylation of wheat embryo proteins, and it was especially interesting to find that when wheat embryo proteins are alkylated by iodo[14C]acetamide, two proteins co-dominate the distribution of radioalkylated products in dodecylsulphate/polyacrylamide gels: Ec and wheat germ agglutinin. Using co-electrophoresis with the isotopically labeled protein to detect a dye-staining counterpart, Ec has been purified by combined cation-exchange and gel-filtration chromatography of alkylated wheat germ proteins. The purified protein can be recovered in milligram quantity (5-10 mg/100 g wheat germ) and compositional analysis shows that it is unusually rich in cysteine (approx. 15%) and glycine (approx. 17%), as is wheat germ agglutinin.     

Review: The cytogenetic and molecular architecture of chromosome 1R—one of the most widely utilized sources of alien chromatin in wheat varieties

Conclusions The evolution of chromosome 1R has resulted in a structure with genes that are similar enough, qualitatively and quantitatively, to those in wheat to allow substitution for wheat chromosomes. The sequences dispersed between the genes, and those arranged tandemly in large blocks, have however undergone major quantitative changes (and possibly qualitative changes as well). Amplification events since the time that wheat and rye have been separated in an evolutionary sense have generated arrays of repetitive sequence families that characterize the rye chromosomes (including 1R) and distinguish them from wheat chromosomes. The genetic mapping of chromosome 1R at the level of DNA has provided a range of probes for the study of 1R chromosome segments as they are manipulated in commercial wheat cultivars.The extensive utilization of chromosome 1R as a source of disease resistance genes in wheat implies that rye genes are normally expressed in a wheat background. This is, however, not always the case and a particularly well studied example is the suppression of rRNA gene expression (reviewed in Applels et al. 1986a). These isolated examples of modified expression of rye genes in a wheat background are presumably the result of evolutionary change in the rye promoter regions resulting in their reduced competitiveness when combined with wheat genes in a common cytoplasmic environment. The cytoplasm of wheat plants carrying rye chromosome fragments would be dominated by protein molecules adapted to wheat promoters.     

Use of fluorescence genomic in situ hybridization (GISH) to detect the presence of alien chromatin in wheat lines differing in nuclear DNA content

BACKGROUND: Many times small differences in genome size are reported between or within plant species in which no cytologic confirmation is made. Attempts to repeat these studies have met with limited success. The controversy then becomes whether or not these small differences that were not confirmed cytologically are real. The present study was undertaken to determine if the approximately 1% nuclear variation seen by flow cytometry among wheat lines selected for aluminum response was due to actual chromatin differences. METHODS: The three parental wheat cultivars used in the aluminum selection along with the isolines resulting from the selection were analyzed. One parental line had previously been reported to have alien chromatin substituted for the corresponding wheat homologous chromatin. Genomic in situ hybridization was used to determine the presence or absence of rye chromatin in three cultivars and six near-isolines of wheat. RESULTS: Upon observing metaphase chromosomes of the Century parent and its isolines, two of the chromosomes were observed to be one-half yellow-orange, indicating rye chromatin with the remaining portion of the chromosomes and the other 40 wheat chromosomes having no label indicating wheat chromatin. In the Chisholm parent and its isolines, none of the chromosomes were labeled, indicating the absence of rye chromatin. In addition, none of the third parents' chromosomes had the rye yellow-orange signal. CONCLUSIONS: The wheat lines with the larger DNA contents were observed to have alien DNA present. DNA differences between the normal wheat chromosomes and the substituting alien chromatin were calculated based on total chromosome length. The increase in genome size of the wheat lines containing the alien chromatin appears to be the result of the alien chromatin having approximately 43% more DNA than the wheat chromatin it is replacing. Thus, the small DNA difference previously reported by flow cytometry was demonstrated to be a real DNA variation due to the presence of small fragments of alien chromosomes added to the wheat genome.     

Partial inactivation of wheat nucleolus organisers by the nucleolus organiser chromosomes from Aegilops umbellulata

Two pairs of chromosomes (1U and 5U) in Aegilops umbellulata possess ribosomal RNA genes. This has been proven by studying wheat plants into which 1U and 5U chromosomes have been introduced separately. These plants have more ribosomal RNA genes than the recipient wheat plants and additional clusters of rDNA when examined by in situ hybridisation. The repeating rDNA unit in Aegilops umbellulata is longer than most of the units in the wheat variety Chinese Spring, the additional DNA probably being in the non-transcribed spacer. This was determined from restriction endonuclease maps of rDNA. In Chinese Spring plants possessing 1U or 5U chromosomes, the largest nucleoli are formed on 1U or 5U chromosomes and the wheat nucleolus organisers form micronucleoli. This is not because the nucleolus organisers on chromosomes 1U and 5U have many more rRNA genes than wheat nucleolus organisers. It is suggested that the Aegilops umbellulata nucleolus organisers are dominant over those of wheat because they compete more effectively for some limiting factor. — The partial inactivation of the wheat nucleolus organisers by chromosomes 1U or 5U does not result in a reduced total nucleolus volume in root tip or pollen mother cells, because of the compensation by the nucleolus organisers of chromosomes 1U or 5U. The amount of RNA in seedlings is not markedly affected by the partial inactivation of the wheat nucleolus organisers.     

Mechanism of antimutagenicity of wheat sprout extracts.

In this paper we have demonstrated that wheat sprout extract, which has been shown to be antimutagenic towards benzo[a]pyrene (BP), reduced formation of BP metabolites by hepatic microsomes of either benzo[a]pyrene- or phenobarbital-treated rats as analyzed in high-pressure liquid chromatography (HPLC). Comparing the time dependence of profiles and values of BP metabolites, formed in experiments in which the same dose of wheat sprout extract was added to the incubation medium, it has been observed that the later this extract was added the higher the percent of BP that was metabolized. In a bacterial test (cytochrome P450 induction assay) high inhibition of mutagenic activity of cyclophosphamide and ethidium bromide, in the presence of wheat sprout extract, reflected decreased levels of cytochromes P4502B1 and P4501A1 respectively. Decreased levels of both cytochromes P4501A1 and P4502B1 were also observed in either wheat sprout extract- or wheat sprout extract plus benzo[a]pyrene-treated rats. In all of these studies it has been observed that wheat sprout extract displays much more affinity for cytochrome P4501A1 than for the P4502B1 form. On the other hand the wheat sprout extract had higher affinity for carcinogen binding protein (4S protein) than for the aryl hydrocarbon receptor. The strong inhibition of BP mutagenicity and BP metabolism with non-chlorophyllic wheat sprout extract suggests that chlorophyll is not the main compound responsible for the antimutagenic activity of wheat sprout extract. The similar chromatographic behavior of both the main inhibitory fraction, obtained from wheat sprout extract, and two pure glycosides of apigenin--shaftoside, purified from wheat sprout extract and synthetic swertisine--suggests that antimutagenic compound(s) contained in the wheat sprout extract belong(s) to this family of flavonoids.     

Molecular cytogenetic and genomic analyses reveal new insights into the origin of the wheat B genome

Key message

This work pinpointed the goatgrass chromosomal segment in the wheat B genome using modern cytogenetic and genomic technologies, and provided novel insights into the origin of the wheat B genome.

Abstract

Wheat is a typical allopolyploid with three homoeologous subgenomes (A, B, and D). The donors of the subgenomes A and D had been identified, but not for the subgenome B. The goatgrass Aegilops speltoides (genome SS) has been controversially considered a possible candidate for the donor of the wheat B genome. However, the relationship of the Ae. speltoides S genome with the wheat B genome remains largely obscure. The present study assessed the homology of the B and S genomes using an integrative cytogenetic and genomic approach, and revealed the contribution of Ae. speltoides to the origin of the wheat B genome. We discovered noticeable homology between wheat chromosome 1B and Ae. speltoides chromosome 1S, but not between other chromosomes in the B and S genomes. An Ae. speltoides-originated segment spanning a genomic region of approximately 10.46 Mb was detected on the long arm of wheat chromosome 1B (1BL). The Ae. speltoides-originated segment on 1BL was found to co-evolve with the rest of the B genome. Evidently, Ae. speltoides had been involved in the origin of the wheat B genome, but should not be considered an exclusive donor of this genome. The wheat B genome might have a polyphyletic origin with multiple ancestors involved, including Ae. speltoides. These novel findings will facilitate genome studies in wheat and other polyploids.