Bioengineering potato plants to produce benzylglucosinolate for improved broad-spectrum pest and disease resistance

Transgenic Research - In traditional, small-scale agriculture in the Andes, potatoes are frequently co-cultivated with the Andean edible tuber Tropaeolum tuberosum, commonly known as mashua, which...     

Phylogeographic patterns of steppe species in Eastern Central Europe: a review and the implications for conservation

The phylogeography of species associated with European steppes and extrazonal xeric grasslands is poorly understood. This paper summarizes the results of recent studies on the phylogeography and conservation genetics of animals (20 taxa of beetles, butterflies, reptiles and rodents) and flowering plants (18 taxa) of such, "steppic" habitats in Eastern Central Europe. Most species show a similar phylogeographic pattern: relatively high genetic similarity within regional groups of populations and moderate-to-high genetic distinctiveness of populations from currently isolated regions located in the studied area. This distinctiveness of populations suggests a survival here during glacial maxima, including areas north of the Bohemian Massif-Carpathians arc. Steppic species generally do not follow the paradigmatic patterns known for temperate biota (south-north “contraction–expansion”), but to some extent are similar to those of arctic-alpine taxa. There are three main groups of taxa within Eastern Central Europe that differ in their contemporary distribution pattern, which may reflect historical origin and expansion routes. Present diversity patterns of the studied steppic species suggest that they share a unique genetic signature and distinct assemblages exist in each of the now isolated areas rich in steppic habitats. At least some of these areas probably act as present “interglacial refugia” for steppic species. This study strongly supports the need to protect steppic species throughout their entire ranges in the region, as the continuous destruction of steppic habitats in some areas may lead not only to the disappearance of local populations, but also to the extinction of unique evolutionary units.     

Comparison of chito-oligosaccharide production from three different colloidal chitosans using the endochitonsanolytic system of Bacillus thuringiensis

Bacillus thuringiensis is a nonhuman pathogen bacterium that is used as a fungal and insect biocontrol agent. Because of its environmental interaction, it possesses several extracellular enzymes that are able to degrade chitin and chitosan, two of the most important polymers because of their application in numerous fields. However, in recent years, it has been observed that oligosaccharides from the enzymatic degradation of chitosan have important benefits for human health. Comparison and exploration of the production of chito-oligosaccharides from different sources of chitosan will improve the process parameters and expand the biotechnology based in these molecules. This study shows the production of chito-oligosaccharides from three different sources of colloidal chitosan and conducts a qualitative–quantitative comparison between them, using the extracellular enzyme of B. thuringiensis. We found that in the three substrates, it is possible to get a mixture of chito-oligosaccharides from dimer to hexamer in a concentration range from 0.72 to 8.09?mg?·?g^?1 of original substrate. The best substrate to obtain these molecules was commercial chitosan as it has the highest production yields.     

Excitation of the L intermediate of bacteriorhodopsin: electric responses to test x-ray structures

The L intermediate of bacteriorhodopsin was excited, and its electrical response was measured. Two positive components were found in it with respect to the direction of proton pumping: an unresolved fast component, and a slower one (tau=7 micros) of small amplitude. The fast component was assigned to a charge motion corresponding to reisomerization of the retinal moiety, whereas the slow one was attributed to charge rearrangements reestablishing the ground state. Because three x-ray crystallographic structures have recently been reported for the L intermediate, it seemed important to calculate the intramolecular dipole moment changes associated to bR-->L for all three structures, so as to compare them with similar quantities determined from the electrical signals. The results are discussed in terms of amino acid side chains possibly contributing to the observed effect. We propose to use electrical signals as a verification tool for intermediate structures of the photocycle, and thus for molecular models of proton pumping.     

Relationships between Training Load,Salivary Cortisol Responses and Performance during Season Training in Middle and Long Distance Runners

Purpose

Monitoring training from a multifactorial point of view is of great importance in elite endurance athletes. This study aims to analyze the relationships between indicators of training load, hormonal status and neuromuscular performance, and to compare these values with competition performance, in elite middle and long-distance runners.

Method

Fifteen elite middle and long-distance runners (12 men, 3 women; age = 26.3±5.1 yrs) were measured for training volume, training zone and session rate of perceived exertion (RPE) (daily), countermovement jump (CMJ) and salivary free cortisol (weekly) for 39 weeks (i.e., the whole season). Competition performance was also observed throughout the study, registering the season best and worst competitions.

Results

Season average salivary free cortisol concentrations correlate significantly with CMJ (r = −0.777) and RPE (r = 0.551). Also, weekly averages of CMJ significantly correlates with RPE (r = −0.426), distance run (r = −0.593, p<0.001) and training zone (r = 0.437, p<0.05). Finally, it was found that the CMJ (+8.5%, g = 0.65) and the RPE (−17.6%, g = 0.94) measured the week before the best competition performance of the season were significantly different compared with the measurement conducted the week before the season’s worst competition performance.

Conclusions

Monitoring weekly measurements of CMJ and RPE could be recommended to control training process of such athletes in a non-invasive, field-based, systematic way.