Cross-talk between high light stress and plant defence to the two-spotted spider mite in Arabidopsis thaliana.

Little is known about how plants deal with arthropod herbivores under the fluctuating light intensity and spectra which occur in natural environments. Moreover, the role of simultaneous stress such as excess light (EL) in the regulation of plant responses to herbivores is poorly characterized. In the current study, we focused on a mite-herbivore, specifically, the two-spotted spider mite (TSSM), which is one of the major agricultural pests worldwide. Our results showed that TSSM-induced leaf damage (visualized by trypan blue staining) and oviposition rate (measured as daily female fecundity) decreased after EL pre-treatment in wild-type Arabidopsis plants, but the observed responses were not wavelength specific. Thus, we established that EL pre-treatment reduced Arabidopsis susceptibility to TSSM infestation. Due to the fact that a portion of EL energy is dissipated by plants as heat in the mechanism known as non-photochemical quenching (NPQ) of chlorophyll fluorescence, we tested an Arabidopsis npq4-1 mutant impaired in NPQ. We showed that npq4-1 plants are significantly less susceptible to TSSM feeding activity, and this result was not dependent on light pre-treatment. Therefore, our findings strongly support the role of light in plant defence against TSSM, pointing to a key role for a photo-protective mechanism such as NPQ in this regulation. We hypothesize that plants impaired in NPQ are constantly primed to mite attack, as this seems to be a universal evolutionarily conserved mechanism for herbivores.

Systemic signaling and acclimation in response to excess excitation energy in Arabidopsis.

Land plants are sessile and have developed sophisticated mechanisms that allow for both immediate and acclimatory responses to changing environments. Partial exposure of low light-adapted Arabidopsis plants to excess light results in a systemic acclimation to excess excitation energy and consequent photooxidative stress in unexposed leaves. Thus, plants possess a mechanism to communicate excess excitation energy systemically, allowing them to mount a defense against further episodes of such stress. Systemic redox changes in the proximity of photosystem II, hydrogen peroxide, and the induction of antioxidant defenses are key determinants of this mechanism of systemic acquired acclimation.

Molecular Responses to Photooxidative Stress in Pinus sylvestris (L.) (II. Differential Expression of CuZn-Superoxide Dismutases and Glutathione Reductase.

The influence of photooxidative stress on genes expressing superoxide dismutase (Sod) and glutathione reductase (Gor) was analyzed in needles of top and side shoots of 3-year-old Pinus sylvestris (L.) seedlings. The study was carried out in the field during spring recovery. From mid-April the top shoots of seedlings protruded above the snow and thus were exposed to sunlight, whereas the side shoots were covered with snow until May 4. Needles were sampled from top and side shoots on five different occasions. At the beginning of May the mRNA levels for cytosolic CuZn-Sod were significantly higher in top-shoot needles than in side-shoot needles. Similar results were obtained for chloroplastic CuZn-Sod mRNA. After May 6 we could not detect any significant differences between top- and side-shoot needles for either CuZn-Sod mRNA level. Transcript accumulation for the chloroplastic CuZn-Sod was up to 4-fold higher than for cytosolic CuZn-Sod in both types of shoots. On June 1 minimum transcript levels were observed for both CuZn-SOD isoforms. Protein activity analysis for CuZn-SOD isozymes did not reveal any significant differences between top- and side-shoot needles during the whole period of measurements. The mRNA level for chloroplastic Gor was similar in both types of shoots. However, the total GR activity was significantly higher in top-shoot needles than in side-shoot needles at the beginning of May. The analysis of mRNA accumulation for chloroplastic CuZn-Sod and Gor indicates that transcript levels were at least 5- to 20-fold higher for CuZn-Sod than for chloroplastic Gor. The differential expressions of Sod and Gor genes are discussed in relation to regulation of the enzymic scavenging system during photooxidative stress conditions.

Lupin chloroplast and mitochondrial tRNA populations and their genes.

Transfer RNAs isolated from lupin chloroplasts and mitochondria were compared by two-dimensional gel electrophoresis. Twenty chloroplast and 24 mitochondrial tRNA species were identified. The saturation hybridization between lupin chloroplast DNA and 125I-labelled lupin chloroplast tRNAs pointed to the presence of about 34 tRNA genes in lupin chloroplast DNA. The number of mitochondrial tRNA genes estimated by the same method was about 30 genes. EcoRI restriction digest of lupin mitochondrial DNA probed with 32P-labelled lupin mitochondrial tRNAs revealed only a small number of positive restriction fragments. Some of these mitochondrial restriction fragments hybridized with 32P-labelled chloroplast tRNA.

Organization of the 18S, 5S, 4S rRNA genes and the tRNA-like repeat in the mitochondrial genomes of three lupin species.

Southern blots of mitochondrial (mt) DNAs of three Lupinus species cleaved with three restriction enzymes were probed with Lupinus luteus mtDNA fragments containing 18S, 5S rRNA genes or a tRNA-like repeat. Comparison of the number of hybridizing bands and their intensity suggested that the mt 18S and 5S rRNA genes occur mostly in one copy in the genomes of three lupin species. The exception concerned the Lupinus angustifolius 5S rRNA gene showing two hybridizing bands of unequal intensity. The results of hybridization of the lupin mitochondrial genomes with a probe specific for the Lupinus luteus tRNA-like repeat pointed to the presence of such a repeat in other parts of the genomes besides the vicinity of the 18S rRNA gene. Northern hybridization analysis showed the presence of 18S, 5S and tRNA-like repeat transcripts similar in size in all lupin species.

[Dexamethasone test in the assessment of depression grade in patients with low back pain]. / Zastosowanie testu deksametazonowego dla oceny stopnia depresji u chorych z bólami krzyza.

The results of the dexamethasone test were compared with the depression depth and pain intensity in patients with low back pain caused by degenerative changes and/or disc prolapse. In the light of these studies no correlation was demonstrated between the positive results of the dexamethasone test and depression symptoms and the intensity and duration of pain.

[Assessment of dexamethasone effectiveness in the treatment of ischalgia]. / Ocena skutecznosci leczenia rwy kulszowej deksametazonem.

The authors studied 43 patients admitted to hospital with acute episodes of ischalgia or recurrences caused by intervertebral disc disease. The patients were randomly selected into two groups treated with dexamethasone in high but rapidly decreasing doses, or tramadol. A comparison of the results in both groups showed that dexamethasone was effective and safe when given by this method to patients with ischalgia.

[Work environment and health status of agricultural aviation personnel]. / Srodowisko pracy i stan zdrowia personelu latajacego agrolotnictwa.

The morbidity rate and present health status of flying agricultural aviation personnel under health care of the Main Military Medical Committee for aviation workers were analysed and compared with another group of helicopter pilots. A detailed clinical examination of 77 "Agro" pilots indicated more trauma cases than idiopathic diseases cases, some of those trauma cases were due to professional work. Analysis of the present health status indicated the predominance of pilots with just one health disturbance, pilots with no health disturbances taking the second position in the comparison. The health deviations did not differ from those in other populations, as classified by pilots' age. On the other hand, their percentage was higher than in helicopters pilots control group. Average age of "Agro" pilots was relatively high and number of hours spent in air considerable, too.

[Analgesic effect of imipramine in the treatment of ischium pain and circadian rhythm of cortisol release into the serum]. / Efekt przeciwbólowy imipraminy w leczeniu rwy kulszowej a okolodobowy rytm wydzielania kortyzolu w surowicy.

In the paper the results are presented of treatment of ischialgia with Imipramine, taking into account the circadian rhythm of cortisol release into the serum. The obtained results encourage to the use of tricyclic antidepressants in the treatment refractory cases of ischialgia. No significant differences were observed in the circadian rhythm of cortisol release into the serum before and after the treatment with Imipramine.

The effect of atmospheric pollution on α-glycerophosphate dehydrogenase activity in the satin moth (Leucoma salicis (L.)).

The purpose of this study was to investigate how various combinations of atmospheric pollutants may affect α-GPDH activity in the satin moth. Enzyme activity was measured in crude larva and pupa as well as in hoogenates from the fat body and thoracic muscles of adults. The insects were divided into five groups and treated with dust (containing heavy metals) and gaseous pollutants (SO2, NOx) in different concentrations. Specific activity of α-GPDH was the highest in thoracic muscles of adult satin moth and was significantly higher in males, regardless of their origin. Low concentration of SO2 caused stimulation of enzyme activity but simultaneous action of SO2, NOx and heavy metal containing dust with accompanied acid precipitation caused inhibition of α-GPDH activity, probably as the result of sulphite bounds with pyridine and flavin nucleotides.