Project description:We conducted two amiRNA (amiR417 and amiR519) transgenic lettuce lines. In order to confirm that the target artificial miRNAs (amiR417 and amiR519) were correctly transcribed and analysis the cleavage sites of the 3’ and 5’ ends of amiR471, small RNA fragments were extracted from ten independent positive T2 generations and examined using Solexa deep sequencing.
Project description:Chitin soil amendment is known to improve soil quality, plant growth and plant stress resilience, but the underlying mechanisms are not well understood. In this study, we monitored chitin’s effect on lettuce physiology every two weeks through an eight-week growth period, analyzed the early transcriptional reprogramming and related metabolomic changes of lettuce, in response to crab chitin treatment in peat-based potting soil. In commercial growth conditions, chitin amendment still promoted lettuce growth, increased chlorophyll content, the number of leaves and crop head weight from week six. The flavonoid content in lettuce leaves was altered as well, showing an increase at week two but a decrease from week six. Transcriptomic analysis showed that over 300 genes in lettuce root were significant differentially expressed after chitin soil treatment. Gene Ontology-term (GO) enrichment analysis revealed statistical overrepresentation of GO terms linked to photosynthesis, pigment metabolic process and phenylpropanoid metabolic process. Further analysis of the differentially expressed genes (DEGs) showed that the flavonoid pathway is mostly upregulated whereas the bifurcation of upstream phenylpropanoid pathway towards lignin biosynthesis is mostly downregulated. Metabolomic analysis revealed the upregulation of salicylic acid, chlorogenic acid, ferulic acid, and p-coumaric acid in chitin treated lettuce seedlings. These phenolic compounds mainly influence the phenylpropanoid biosynthesis pathway and may play important roles in plant defense reactions. Our results suggest that chitin soil amendments might activate induced resistance by priming lettuce plants and promote lettuce growth via transcriptional changes.
Project description:We performed RNA-sequencing of Bgh-infected barley leaves at two different time-points after infection to examine gene expression in the barley powdery mildew isolate DH14 during plant pathogenesis.
Project description:UV-B radiation is one of the major environmental stresses that triggers a variety of plant responses. However, limited information is available regarding plant biological reactions which help to circumvent the potentially harmful effects of UV-B radiation in lettuce (Lactuca sativa L.). In this study, RNA-seq was performed to identify differentially expressed genes in response to UV-B radiation.
Project description:Increasing evidence of Pseudomonas aeruginosa on fresh plant-based foods raises food safety concerns. While internalization of pathogens such as Salmonella enterica in vegetables such as lettuce is well documented, corresponding data for P. aeruginosa are lacking. Moreover, climate change-associated temperature shifts may influence the plant microbiota and the presence of human pathogens. This study investigates the internalization and temperature-dependent gene expression of P. aeruginosa PAO1 on green oak leaf lettuce as a model system. For this purpose, oak leaf lettuce was cultivated in soil inoculated with P. aeruginosa PAO1_sfGFP_UHH07, and internalization was analyzed using confocal laser scanning microscopy. Temperature-dependent transcriptomic changes of P. aeruginosa PAO1 were assessed by analyzing differentially expressed genes following plant inoculation and incubation at 18 and 22 °C, respectively. P. aeruginosa PAO1 is capable of internalizing into the roots of oak leaf lettuce, but a translocation into leaves was not detected. Transcriptomic analyses showed that a moderate temperature increase shifts bacterial gene expression, with virulence genes upregulated at 22 °C and persistence-associated genes predominating at 18 °C. These results show that temperature influences the persistence and pathogenic potential of P. aeruginosa present on oak leaf lettuce, highlighting potential impacts of climate change on food safety.