Project description:The characteristic leaf shapes we see in all plants are in good part outcome of the combined action of several transcription factor networks that translate into cell division activity during the early development of the organ. We show here that wild-type leaves have distinct transcriptomic profiles in center and marginal regions. Certain transcripts are enriched in margins, including those of CINCINNATA-like TCPs, and members of the NGATHA (NGA) and STYLISH (STY) gene families. We study in detail the contribution of miR319 regulated TCP (Teosinte branched, Cycloidea, PCF1/2) transcription factors to the development of the center and marginal regions of Arabidopsis leaves. We compare in molecular analyses wildtype, a tcp2 tcp4 mutant that has enlarged flat leaves and a tcp2 tcp3 tcp4 tcp10 mutant with strongly crinkled leaves. The different leaf domains of the tcp mutants show changed expression patterns for many photosynthesis related genes, indicating delayed differentiation, especially in the marginal parts of the organ. At the same time, we found an upregulation of cyclin genes and other genes that are known to participate in cell division, specifically in the marginal regions of tcp2 tcp3 tcp4 tcp10. Using GUS reporter constructs we confirmed extended mitotic activity in the tcp2 tcp3 tcp4 tcp10 leaf which persisted in small defined foci in the margins when the mitotic activity had already ceased in wild-type leaves. Our results describe the role of miR319-regulated TCP transcription factors in the coordination of activities in different leaf domains during the organs development.
Project description:In order to investigate the physiological and biochemical characteristics and molecular mechanisms during the leaf colour change of Acer rubrum L, this study used Acer rubrum L. 'Autumn Blaze' cuttings as material and analysed the transcriptome and miRNAs of Acer rubrum L leaves under different light and temperature treatments. The transcriptome and miRNAs of Acer rubrum L leaves were analysed under different light and temperature treatments, and miRNA-mRNA association analysis was performed for the differentially expressed mRNAs and miRNAs.
Project description:Many signalling pathways are involved in controlling gene expression during plant senescence. Pathways involving SA, JA and ethylene have a role in senescence but none are essential for the senescence process to occur. The aim of this experiment is to classify senescence-enhanced genes into groups depending on the signalling pathways that regulate them. This will provide useful information on the relative importance of each signalling pathway during senescence and allow us to separate potential senescence-specific genes and pathways from the stress response pathways.Mutants in genes in the ethylene pathway (ein2) and the jasmonate pathway (coi1) and the NahG transgenic plant which is defective in the salicylic acid pathway will be grown until the mid flowering stage. Fully developed green and partially senescent leaves will be harvested from the plants at this stage. In addition, two different lines of Arabidopsis (Col-5 glabrous and Col-0) will be grown as controls. Leaves will be harvested from the two control plants before flowering (green) and at mid flowering as above. The control plants will be harvested at two stages to identify the senescence- enhanced genes. The effects of each mutation on the senescence related expression of these genes will then be studied.Mutant RNAs will be isolated in duplicate. The two control accessions will act as replicates for the wild type. Two wild type accessions will be used to reduce possible differences that could be observed the mutants due to slight differences in background.
