OE Lines Research Articles

The conserved factor DE-ETIOLATED 1 cooperates with CUL4-DDB1DDB2to maintain genome integrity upon UV stress

Plants and many other eukaryotes can make use of two major pathways to cope with mutagenic effects of light, photoreactivation and nucleotide excision repair (NER). While photoreactivation allows direct repair by photolyase enzymes using light energy, NER requires a stepwise mechanism with several protein complexes acting at the levels of lesion detection, DNA incision and resynthesis. Here we investigated the involvement in NER of DE-ETIOLATED 1 (DET1), an evolutionarily conserved factor that associates with components of the ubiquitylation machinery in plants and mammals and acts as a negative repressor of light-driven photomorphogenic development in Arabidopsis. Evidence is provided that plant DET1 acts with CULLIN4-based ubiquitin E3 ligase, and that appropriate dosage of DET1 protein is necessary for efficient removal of UV photoproducts through the NER pathway. Moreover, DET1 is required for CULLIN4-dependent targeted degradation of the UV-lesion recognition factor DDB2. Finally, DET1 protein is degraded concomitantly with DDB2 upon UV irradiation in a CUL4-dependent mechanism. Altogether, these data suggest that DET1 and DDB2 cooperate during the excision repair process.

Improve freezing tolerance in transgenic poplar by overexpressing a ω-3 fatty acid desaturase gene

Polyunsaturated fatty acids are a major component of glycerolipids in plant cellular membranes, and play important role in the maintenance of its fluidity. In this study, we isolated a novel ω-3 fatty acid desaturase gene (PtFAD3) from Populus tomentosa Carr. and transformed it into hybrid poplar (Populus alba × P. glandulossa) K84 lines by overexpression and RNAi silencing methods. Quantitative PCR analysis revealed varied expression levels of PtFAD3 among the transgenic lines. Two overexpressing lines (OE lines) and two gene down-regulated RNAi lines (DR lines) were chosen for further analysis. The level of the major trienoic fatty acid species, linolenic acid, increased by an average of 10% in the two OE lines and decreased by an average of 5% in the two DR lines. When young poplar cuttings with three leaves were exposed to a freezing temperature (−4°C) for 3 h without cold acclimation, survival rates of the two independent OE lines (70 and 77%) were far superior to the wild type (36.7%) and the two DR lines (10% for both). Damage caused by freezing was alleviated significantly in the two OE lines compared to wild-type controls. Phenotypic evaluation indicated that the variable responses to freezing were attributable to genotypic variation. Therefore, in the case of poplar, a significant increase in freezing tolerance was achieved on a small scale following the introduction of PtFAD3. This strategy can be used for freezing tolerance breeding in hybrid poplar and other economically important forest trees.

Anomalies of magnetic properties of layered crystals InSe containing Mn

Static magnetic susceptibility and ESR spectra of layered semiconducting InSe crystals containing Mn were investigated. Solid solution In1−XMnXSe is responsible for ferromagnetism at Curie temperature TC>270 K. Single wide line ESR spectrum was observed. It practically disappeared at 90 K. Paramagnetic constant background of magnetic susceptibility originates from atypical Van-Vleck Mn3+ (d4) ions, which are in a state of nonmagnetic singlet in crystal field, and magnetization of crystals in ferromagnetic state. Very narrow (2 Oe) line with g=1.999 appears at temperatures lower than 23 K which is apparently due to the electrons localized on the levels of space quantization. Two maxima at ∼160 K and ∼260 K are observed as the temperature dependence of magnetic susceptibility. They are obliged to inclusions of antiferromagnetic MnSe. At high magnetic fields of 6 and 50 kOe, the first peak widens and disappears.

Root Loci of Retarded Control Systems

This is an attempt to apply the root locus method to process control systems and to bring the method closer to optimum adjustments theories. Typical root loci graphically traced are shown with superposed constant setting lines to show the effects of controller adjustments, optimum points suggested thus far are also plotted in them. The controller actions treated are from proportional to three term modes as defined by eq. 3. The process was assumed to be single capacity plus dead time types, fig. 3 and eq. 5. Figs. 4 and 5 are principles of graphical solution for dimensionless form of loop transfer function of eq. 7. Figs. 7 to 9 are root loci for respective modes of control. The 25% damping condition is expressed by OE lines in the figures. This line in fig. 7, J and C in fig. 8, and C in fig. 9 are for Cohen-Coon's optimum. ZN and J in fig. 7, Z in fiig. 8 are Ziegler-Nichols's optimum, and T in the figures are Takahashi's optimum defined as the minimum control area of transient response.

Lift-Patterns in Old English Verse

In the study of Old English metrics (and of old Germanic versification as a whole) heed has been given to feet or measures, but less has been said about rhythmical patterns as such. The present paper is an attempt to classify OE lines of verse in terms of rhythmical pattern alone; more precisely, in terms of the sequences of rhythmical high points which these lines exhibit. The one-sided character of such a classification will be obvious.' If I undertake it nevertheless, I do so in the hope that it will throw light on the subject and lead to further work in the field. The rhythm of Old English verse grew naturally out of the prose rhythm, by a process of heightening and lowering. A metrically heightened syllable may be called a lift (German hebung); a metrically lowered syllable may be called a drop (German senkung). The lifts in a line of verse regularly coincided with syllables which would (or might) take stress if the line were read as prose; in like manner, the drops coincided with syllables which would (or might) be without prose stress. In other words, the metrical heightening and lowering never did violence to the natural prose rhythm, which depended on the sequence of stressed and unstressed syllables. We may further distinguish three kinds of lifts. A major or primary lift is a stressed syllable metrically heightened and reinforced by alliteration or rime. A minor or secondary lift is a stressed syllable metrically heightened but not reinforced by alliteration or rime. A tertiary lift differs from a secondary in that the metrical heightening takes place at a lower level. Primary, secondary and tertiary lifts will here be symbolized by the numerals 1. 2 and 3. A hyphen will be used to symbolize the boundary between the on-verse (or first half-line) and the off-verse (or second half-line) of an OE alliterative line. The initial sound of each lift will be italicized in the lines quoted. Upon occasion the stave-pattern (or alliterative pattern) of the line as well as its lift-pattern will be given.2