The strawberry (Fragariaxananassa) fruit-specific rhamnogalacturonate lyase 1 (FaRGLyase1) gene encodes an enzyme involved in the degradation of cell-wall middle lamellae.

Pectins are essential components of primary plant cell walls and middle lamellae, and are related to the consistency of the fruit and its textural changes during ripening. In fact, strawberries become soft as the middle lamellae of cortical parenchyma cells are extensively degraded during ripening, leading to the observed short post-harvest shelf life. Using a custom-made oligonucleotide-based strawberry microarray platform, a putative rhamnogalacturonate lyase gene (FaRGlyase1) was identified. Bioinformatic analysis of the FaRGlyase1 sequence allowed the identification of a conserved rhamnogalacturonate lyase domain, which was also present in other putative RGlyase sequences deposited in the databases. Expression of FaRGlyase1 occurred mainly in the receptacle, concurrently with ripening, and it was positively regulated by abscisic acid and negatively by auxins. FaRGLyase1 gene expression was transiently silenced by injecting live Agrobacterium cells harbouring RNA interference constructs into fruit receptacles. Light and electron microscopy analyses of these transiently silenced fruits revealed that this gene is involved in the degradation of pectins present in the middle lamella region between parenchymatic cells. In addition, genetic linkage association analyses in a strawberry-segregating population showed that FaRGLyase1 is linked to a quantitative trait loci linkage group related to fruit hardness and firmness. The results showed that FaRGlyase1 could play an important role in the fruit ripening-related softening process that reduces strawberry firmness and post-harvest life.

Degradation of simazine by microorganisms isolated from soils of Spanish olive fields.

The capability of the microbial flora isolated from an olive field soil from Andalusia to mineralize simazine has been analyzed. From this soil, a group of bacteria capable of degrading 60 mg simazine litre(-1) in less than a week has been isolated. These microorganisms showed a low capacity for degrading this herbicide to carbon dioxide. When total DNA was isolated from this group of bacteria, we were able to detect by PCR the presence of only the atzC and the trzN genes. Some components of this bacterial population have been identified by sequencing of specific fragments from bacterial 16S rDNA, including Variovorax sp, Pseudoxanthomonas mexicana Thierry et al, Acidovorax sp and Methylopila capsulata Doronina et al. These data suggest that this consortium of bacteria performs an incomplete degradation of the simazine

Intoxicaçäo saturnínica em mecânicos de veículos auto-motores da cidade de Ribeiräo Preto - SP / Lead poisoning among automobile mechanics in garages in the city of Ribeiräo Preto - SP

Os autores estudam a intoxicaçäo saturnínica entre os mecânicos de oficinas da cidade de Ribeiräo Preto. De um total de quinhentas e vinte e duas oficinas, foram sorteadas aleatoriamente cinquenta e duas e todos os cento e oitenta e um trabalhadores dessa amostra foram submetidos ao teste de dosagem da coproporfirina urinária, segundo a técnica modificada por Ribeiro & Stettiner. Para grupo controle foi sorteada aleatoriamente uma amostra de oito serrarias da mesma cidade e os trinta e nove trabalhadores dessa amostra foram submetidos ao mesmo teste (trabalhadores näo expostos ao chumbo). Enquanto trinta e três (18,2%) dos mecânicos apresentaram exames de urina positivos, nenhum serrador apresentou positividade. Há portanto, uma clara evidência de que os mecânicos se intoxicam pelo chumbo. Os autores discutem ainda alguns aspectos gerais da prevençäo do saturnismo