Light signaling via the phytochrome A (phyA) photoreceptor controls basic plant developmental processes including de-etiolation and hypocotyl elongation. We have identified a new Arabidopsis mutant, pat (phytochrome signal transduction)1-1, which shows strongly reduced responses in continuous far-red light. Physiological molecular data indicate that this mutant is disrupted at an early step of phyA transduction. The PAT1 gene encodes cytoplasmic protein 490 amino acids with sequence...

The photoreceptor phytochrome (phy) A has a well-defined role in regulating gene expression response to specific light signals. Here, we describe new Arabidopsis mutant, laf1 (long after far-red 1) that an elongated hypocotyl specifically under light. Gene studies showed reduced responsiveness continuous but retains wild-type responses other wavelengths. As is only perceived by phyA, our results suggest LAF1 involved phyA signal transduction. Further analyses revealed affected subset of...

Abstract Photoreceptors, especially the far-red light-absorbing phytochrome A, play a crucial role in early seedling development, triggering transition from etiolated to photomorphogenic growth. Here, we describe biological functions of two GRAS proteins Arabidopsis (Arabidopsis thaliana), SCARECROW-LIKE21 (SCL21) and PHYTOCHROME A SIGNAL TRANSDUCTION1 (PAT1), which are specifically involved signal transduction. Loss-of-function mutants show an elongated hypocotyl under light impaired other...

Phytochrome A (phyA) mediates different photoresponses what may be connected with the existence of its two types, phyAʹ and phyAʹʹ, differing by spectroscopic, photochemical functional properties. We investigated a role phyA phosphorylation in their formation turning to transgenic Arabidopsis thaliana (L. Heynh.) or phyAphyB mutants overexpressing rice wild-type (phyA WT) mutant SA) first 10 serines substituted alanines. This prevents at these sites modifies photoresponses. Etiolated...

Owing to duplication events in its progenitor, more than 90% of the genes Arabidopsis thaliana genome are members multigene families. A set 2108 gene families, each consisting precisely two unlinked paralogous genes, was identified nuclear A. on basis sequence similarity. systematic method for creation double knock-out lines such pairs, designated as DUPLO lines, established and 200 now publicly available. Their initial phenotypic characterisation led identification seven with defects that...

Since the sequencing of nuclear genome Arabidopsis thaliana ten years ago, various large-scale analyses gene function have been performed in this model species. In particular, availability collections lines harbouring random T-DNA or transposon insertions, which include mutants for almost all ~27,000 A. genes, has crucial success forward and reverse genetic approaches. foreseeable future, genome-wide phenotypic data from mutant will become available Arabidopsis, stimulate a flood novel...

The promoter region -118/-29 of the spinach PetH gene encoding ferredoxin-NADP(+)-oxidoreductase contains crucial cis-elements for regulated expression, while sequences 5'-untranslated leader determine quantitative expression chimeric GUS fusions in transgenic tobacco. Deletion PetE and PsaF genes (for plastocyanin subunit III photosystem I, respectively) results also a decline activity. Appropriate constructs run-on transcription assays demonstrate unambiguously that leaders all three are...

Run‐on assays with isolated nuclei demonstrate that the transcription rates of AtpC and AtpD (gene products: CF 1 subunits γ δ chloroplast ATP synthase) are comparable in spinach seedlings. However, chimeric GUS gene fusions 5′‐flanking regions direct an approximately 10‐fold lower level transgenic tobacco compared equivalent fragments from gene. Both promoters contain sequences vicinity respective TATA boxes, which sufficient to light‐regulated, plastid‐dependent organ‐specific expression...

We have analyzed plastid and nuclear gene expression in tobacco seedlings using the carotenoid biosynthesis inhibitor nor-flurazon. mRNA levels for three nuclear-encoded chlorophyll-binding proteins of photosystem I II (CAB CP 24 apoprotein) are no longer detectable photobleached seedlings, whereas those other components thylakoid membrane (the 33- 23-kD polypeptides Rieske Fe/S polypeptide) accumulate to some extent. Transgenic with promoter fusions from genes exhibit a similar behavior:...

Plastid‐ and light‐regulated expression of the spinach PsaD gene in transgenic tobacco requires sequences downstream transcription start site, promoter alone are not sufficient to respond these stimuli. The mRNA level is still plastid‐ light‐responsive when intron‐containing unit driven by 35S RNA CaMV indicating that contains (a) gene‐internal control element(s). If genomic sequence latter construct was replaced cDNA, a constitutive transcript observed. It concluded intron contributes...

To sense ambient light conditions in order to optimize their growth and development, plants employ a battery of photoreceptors responsive quality quantity. Essential for the sensing red far-red (FR) is phytochrome family photoreceptors. Among them, A special because it mediates responses different conditions, including both very low fluences (very fluence response [VLFR]) high irradiances (high irradiance [HIR]). In contrast with FR-HIR signaling pathway, which several intermediates pathway...

Biogenesis of plastid ribosomes is facilitated by auxiliary factors that process and modify ribosomal RNAs (rRNAs) or are involved in ribosome assembly. In comparison with their bacterial mitochondrial counterparts, the biogenesis less well understood, few have been described so far. this study, we report functional characterization CONSERVED ONLY IN THE GREEN LINEAGE20 (CGL20) Arabidopsis (Arabidopsis thaliana; AtCGL20), which a Pro-rich, ∼10-kD protein targeted to mitochondria...

Phytochrome A plays a major role in early seedling development by triggering the transition from etiolated growth to greening. Seedlings germinated under constant far-red (FR) light show partially de-etiolated phenotype that is not seen phyA mutants. This phytochrome specific response was used screen population of T-DNA mutagenized Arabidopsis seedlings. One mutant line, pat3 (phytochrome signal transduction3), which showed no inhibition hypocotyl elongation FR conditions and FR-induced...

Senescence is a highly regulated process characterized by the active breakdown of cells, which ultimately leads to death plant organs or whole plants. In annual plants such as Arabidopsis thaliana senescence can be observed in each individual leaf. Whether deficiencies photosynthesis promote induction was investigated monitoring chlorophyll degradation, photosynthetic parameters, and reactive oxygen species accumulation mutants. Several mutations affecting components apparatus, including...