59 research outputs found
Transcriptional regulation of the CRK/DUF26 group of Receptor-like protein kinases by ozone and plant hormones in Arabidopsis
Conclusions: Combining expression analysis from multiple treatments with mutants altered in hormone biosynthesis or signalling suggest a model in which O(3) and salicylic acid (SA) activate separate signaling pathways that exhibit negative crosstalk. Although O(3) is classified as an abiotic stress to plants, transcriptional profiling of CRKs showed strong similarities between the O(3) and biotic stress responses
Photosystem II Repair and Plant Immunity: Lessons Learned from Arabidopsis Mutant Lacking the THYLAKOID LUMEN PROTEIN 18.3
Chloroplasts play an important role in the cellular sensing of abiotic and biotic stress. Signals originating from photosynthetic light reactions, in the form of redox and pH changes, accumulation of reactive oxygen and electrophile species or stromal metabolites are of key importance in chloroplast retrograde signaling. These signals initiate plant acclimation responses to both abiotic and biotic stresses. To reveal the molecular responses activated by rapid fluctuations in growth light intensity, gene expression analysis was performed with Arabidopsis thaliana wild type and the tlp18.3 mutant plants, the latter showing a stunted growth phenotype under fluctuating light conditions (Biochem. J, 406, 415-425). Expression pattern of genes encoding components of the photosynthetic electron transfer chain did not differ between fluctuating and constant light conditions, neither in wild type nor in tlp18.3 plants, and the composition of the thylakoid membrane protein complexes likewise remained unchanged. Nevertheless, the fluctuating light conditions repressed in wild-type plants a broad spectrum of genes involved in immune responses, which likely resulted from shade-avoidance responses and their intermixing with hormonal signaling. On the contrary, in the tlp18.3 mutant plants there was an imperfect repression of defense-related transcripts upon growth under fluctuating light, possibly by signals originating from minor malfunction of the photosystem II (PSII) repair cycle, which directly or indirectly modulated the transcript abundances of genes related to light perception via phytochromes. Consequently, a strong allocation of resources to defense reactions in the tlp18.3 mutant plants presumably results in the stunted growth phenotype under fluctuating light.</p
Increased Anion Channel Activity Is an Unavoidable Event in Ozone-Induced Programmed Cell Death
Ozone is a major secondary air pollutant often reaching high concentrations
in urban areas under strong daylight, high temperature and stagnant
high-pressure systems. Ozone in the troposphere is a pollutant that is
harmful to the plant. generation by salicylic and abscisic acids.
Anion channel activation was also shown to promote the accumulation of
transcripts encoding vacuolar processing enzymes, a family of proteases
previously reported to contribute to the disruption of vacuole integrity
observed during programmed cell death.-induced
programmed cell death. Because ion channels and more specifically anion
channels assume a crucial position in cells, an understanding about the
underlying role(s) for ion channels in the signalling pathway leading to
programmed cell death is a subject that warrants future investigation
Ozone induced emissions of biogenic VOC from tobacco: relationships between ozone uptake and emission of LOX products
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