Phänotypische und molekularbiologische Analyse der A. thaliana flower-in-flower Mutante

In der vorliegenden Arbeit wird die A. thaliana flower-in-flower Mutante (fif) phänotypisch und molekularbiologisch charakterisiert. Wichtigstes und auch namensgebendes Merkmal von fif sind sekundäre Blüten, welche sich aus der primären Blüte entwickeln. Des Weiteren ist fif größer als ihr korrespondierender Wildtyp und weist eine höhere Verzweigung der primären Achse auf. Molekularbiologisch wird gezeigt, dass die dem fif-Phänotypen zugrundeliegende Mutation ein Einzelbasenaustausch in LEAFY (LFY) ist, welche zu einem Aminosäurenaustausch führt. Dies beeinflusst die DNA-Bindekapazität des fif-Proteins

Plant Core Environmental Stress Response Genes Are Systemically Coordinated during Abiotic Stresses

Hahn A, Kilian J, Mohrholz A, et al. Plant Core Environmental Stress Response Genes Are Systemically Coordinated during Abiotic Stresses. International journal of molecular sciences. 2013;14(4):7617-7641.Studying plant stress responses is an important issue in a world threatened by global warming. Unfortunately, comparative analyses are hampered by varying experimental setups. In contrast, the AtGenExpress abiotic stress experiment displays intercomparability. Importantly, six of the nine stresses (wounding, genotoxic, oxidative, UV-B light, osmotic and salt) can be examined for their capacity to generate systemic signals between the shoot and root, which might be essential to regain homeostasis in Arabidopsis thaliana. We classified the systemic responses into two groups: genes that are regulated in the non-treated tissue only are defined as type I responsive and, accordingly, genes that react in both tissues are termed type II responsive. Analysis of type I and II systemic responses suggest distinct functionalities, but also significant overlap between different stresses. Comparison with salicylic acid (SA) and methyl-jasmonate (MeJA) responsive genes implies that MeJA is involved in the systemic stress response. Certain genes are predominantly responding in only one of the categories, e.g., WRKY genes respond mainly non-systemically. Instead, genes of the plant core environmental stress response (PCESR), e.g., ZAT10, ZAT12, ERD9 or MES9, are part of different response types. Moreover, several PCESR genes switch between the categories in a stress-specific manner