Toxic secondary metabolite production in genetically modified potatoes in response to stress

Potatoes produce a number of toxic secondary metabolites, which are divided into two groups: the sesquiterpenes and the glycoalkaloids (PGAs): whereas PGAs are largely preformed and present in toxic quantities in both the foliage and "green" potatoes, it is well documented that the levels of PGAs and sesquiterpenes are effected by many biotic an abiotic stresses. The development of genetically modified potato varieties has made it prudent to ascertain whether there may be changes in the amounts or types of these secondary metabolites either as a direct effect of the transgene or due to its interactions with environmental variables. Transgenic potato lines were exposed, along with nontransgenic lines, to a range of biotic and abiotic stresses and a range of environmental conditions in the field and store. Following stressing, a comparison was made of levels of potato glycoalkaloid and sesquiterpene levels between the two groups. Significant differences were observed in the levels of both glycoalkaloid and sesquiterpene levels between transgenic and control material and between infected and noninfected material.     

Soy Protein Isolate versus Meat-Based Low-Protein Diet for Dogs with Congenital Portosystemic Shunts

Background: Both presurgical preparation and long-term support of nonoperable dogs with congenital portosystemic shunts (CPSS) require optimal dietary management. Studies suggested that protein source may play an important role, with vegetable and dairy protein sources having better effects on hepatic encephalopathy (HE) than meat proteins.
Objectives: Determine whether a low-protein test diet with soy as its main protein source results in better scores than a control diet with the same composition but with poultry as its main protein source in dogs with CPSS.
Methods: In a double-blind cross-over study, 16 dogs received each diet for 4 weeks. Dogs in group T first received the test diet and then the control diet, whereas dogs in group C were fed the diets in the opposite order. Different variables (body weight, body condition score, HE score, fecal score, CBC, plasma tests of liver function including NH₃, and coagulation tests) were measured at the start of the study and after completion of each diet.
Results: One-way repeated measures ANOVA was performed. Plasma NH₃ was significantly lower after the test diet than after the control diet. The test diet also resulted in significantly higher fibrinogen concentrations and lower prothrombin times. The HE score improved with both diets, with no significant difference between the 2 diets.
Conclusions: Both diets achieved a significant improvement in HE score. The influence of the soy-based diet on plasma NH₃ concentration and coagulation parameters suggests that such a diet decreases the risk for HE and gives better support of liver function.     

Remnant genetic diversity detected in an ancient crop: Triticum dicoccon Schrank landraces from Asturias, Spain

Emmer wheat, Triticum dicoccon Schrank was one of the founder crops of Neolithic agriculture. Though its cultivation was largely replaced by hexaploid wheats 2000 years ago, pockets of small scale cultivation can still be found. One such area is the Asturias region of Northern Spain, where emmer wheat remains a traditional crop for high value specialist culinary uses, and farmers grow locally adapted landraces. In order to study the diversity of these landraces, we sampled emmer wheat from different regions of Asturias, and genotyped multiple plants from each village using nuclear and chloroplast microsatellites. A high level of variation was observed with markers from both genomes, including a novel chloroplast haplotype. A strong geographic structure was observed in the Asturian emmer wheats in both the chloroplast markers and the nuclear microsatellite data.     

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