Control of early plant development by light quality

This thesis describes how different colours of light affect various aspects of the growth and development of Arabidopsis and tomato plants⁠. In the first chapter, we review the current knowledge of light receptors and different light-regulated processes⁠. In the second chapter we investigated the effect of direct illumination of roots⁠. In the third chapter we presented an overview of the phenotypes that arise when plants are grown in white, red or blue light⁠. In the fourth and fifth chapter we further investigate the stem and flowering phenotypes that were observed in the different light conditions⁠. Altogether we show that red and blue light often act antagonistically, and that some light-regulated processes may be species- or age-specific⁠.NWO14212Plant science

Control of early plant development by light quality

This thesis describes how different colours of light affect various aspects of the growth and development of Arabidopsis and tomato plants⁠. In the first chapter, we review the current knowledge of light receptors and different light-regulated processes⁠. In the second chapter we investigated the effect of direct illumination of roots⁠. In the third chapter we presented an overview of the phenotypes that arise when plants are grown in white, red or blue light⁠. In the fourth and fifth chapter we further investigate the stem and flowering phenotypes that were observed in the different light conditions⁠. Altogether we show that red and blue light often act antagonistically, and that some light-regulated processes may be species- or age-specific⁠.</p

Genomic analysis of European bovine Staphylococcus aureus from clinical versus subclinical mastitis

Intramammary infections (IMI) with Staphylococcus aureus are a common cause of bovine mastitis and can result in both clinical (CM) or subclinical mastitis (SCM). Although bacterial isolates of S. aureus differ in their virulence potential it is largely unclear which bacterial virulence factors are responsible for increased clinical severity. We performed a genome wide association study and used a generalized linear mixed model to investigate the correlation between gene carriage, lineage and clinical outcome of IMI in a collection of S. aureus isolates from cattle with CM (n = 125) and SCM (n = 151) from 11 European countries. An additional aim was to describe the genetic variation of bovine S. aureus in Europa. The dominant lineages in our collection were clonal complex (CC) 151 (81/276, 29.3%), CC97 (54/276, 19.6%), CC479 (32/276, 11.6%) and CC398 (19/276, 6.9%). Virulence and antimicrobial resistance (AMR) gene carriage was highly associated with CC. Among a selection of nine virulence and AMR genes, CC151, CC479 and CC133 carried more virulence genes than other CCs, and CC398 was associated with AMR gene carriage. Whereas CC151, CC97 were widespread in Europe, CC479, CC398 and CC8 were only found in specific countries. Compared to CC151, CC479 was associated with CM rather than SCM (OR 3.62; 95% CI 1.38-9.50) and the other CCs were not. Multiple genes were associated with CM, but due to the clustering within CC of carriage of these genes, it was not possible to differentiate between the effect of gene carriage and CC on clinical outcome of IMI. Nevertheless, this study demonstrates that characterization of S. aureus CC and virulence genes helps to predict the likelihood of the occurrence of CM following S. aureus IMI and highlights the potential benefit of diagnostics tools to identify S. aureus CC during bovine mastitis