scholarly journals Studies on the role of kinetin and vitamin E in the flowering of the cold requiring plant Cichorium intybus) and the long-day plant (Arabidopsis thaliana) grown in non-inductive

2015 ◽  
Vol 36 (1) ◽  
pp. 67-72 ◽  
Author(s):  
M. Michniewicz ◽  
A. Kamieńska
Keyword(s):  
Arabidopsis Thaliana ◽  
Vitamin E ◽  
Cichorium Intybus ◽  
Long Day ◽  
Plant Arabidopsis Thaliana

Phytochrome, photosynthesis and flowering of Arabidopsis thaliana: photophysiological studies using mutants and transgenic lines

2001 ◽  
Vol 28 (5) ◽  
pp. 401 ◽  
Author(s):  
David J. Bagnall ◽  
Rod W. King
Keyword(s):  
Arabidopsis Thaliana ◽  
Photoperiodic Response ◽  
High Irradiance ◽  
Phytochrome A ◽  
Wild Type ◽  
Long Day ◽  
Transgenic Lines ◽  
A Minor ◽  
Type Response ◽  
Plant Arabidopsis Thaliana

A number of phytochrome mutants have been examined for involvement in high irradiance (HIR) or red/far-red (R/FR) end-of-day (EOD) photoresponses during flowering of the long-day (LD) plant, Arabidopsis thaliana (L.) Heynh. A large component of phytochrome A (phyA) response is shown to involve an indirect effect via photosynthesis. When grown autotrophically in soil at a low irradiance (80 mol m–2 s–1), the phyA-211 mutant flowered extremely late compared with wild type and its leaf area was halved, both effects being reversed by increase in photosynthetic irradiance. Supplying sucrose via agar led to very early flowering with little indication of an additional direct phyA HIR. For light-stable phytochrome apoprotein mutants (phyB, phyD) or chromophore mutants (hy1, hy2), flowering was early and R/FR photoreversible EOD response was erased. Conversely, flowering was delayed in a transgenic line overexpressing the PHYB apoprotein. The FR EOD promotion of flowering via phyB was retained in darkness, brief night interruptions mimicking LD response. This novel finding emphasizes the importance of phyB-like phytochromes, with phyA acting indirectly. Whether phyB influences time measurement remains uncertain as we found no rhythmicity in this response to night interruptions. Overall, the role(s) of phytochromes in the regulation of flowering of Arabidopsis include EOD phyB-type response, a minor phyA photoperiodic response, and a large indirect phyA effect involving photosynthesis.

Role of miRNAs in root development of model plant Arabidopsis thaliana

2017 ◽  
Vol 22 (4) ◽  
pp. 382-392 ◽  
Author(s):  
Vibhav Gautam ◽  
Archita Singh ◽  
Swati Verma ◽  
Ashutosh Kumar ◽  
Pramod Kumar ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Root Development ◽  
Model Plant ◽  
Model Plant Arabidopsis Thaliana ◽  
Plant Arabidopsis Thaliana

The role of cytochrome P450 enzymes in the biosynthesis of camalexin

2006 ◽  
Vol 34 (6) ◽  
pp. 1206-1208 ◽  
Author(s):  
E. Glawischnig
Keyword(s):  
Arabidopsis Thaliana ◽  
Cytochrome P450 ◽  
Biosynthetic Pathway ◽  
Model System ◽  
Biosynthetic Gene ◽  
Cytochrome P450 Enzymes ◽  
Model Plant Arabidopsis Thaliana ◽  
Phytoalexin Biosynthesis ◽  
Plant Arabidopsis Thaliana

The biosynthesis of camalexin, the main phytoalexin of the model plant Arabidopsis thaliana, involves at least two CYP (cytochrome P450) steps. It is synthesized from tryptophan via indole-3-acetaldoxime in a reaction catalysed by CYP79B2 and CYP79B3. Based on the pad3 mutant phenotype, CYP71B15 (PAD3) had also been suggested as a camalexin biosynthetic gene. CYP71B15 catalyses the final step in camalexin biosynthesis, as recombinant CYP71B15 and microsomes from Arabidopsis leaves expressing functional PAD3 converted dihydrocamalexic acid into camalexin. The biosynthetic pathway is co-ordinately induced, strictly localized to the site of pathogen infection. This provides a model system to study the regulation of CYP enzymes involved in phytoalexin biosynthesis.

A multigene family of glycosyltransferases in a model plant, Arabidopsis thaliana

2002 ◽  
Vol 30 (2) ◽  
pp. 301-306 ◽  
Author(s):  
D. Bowles
Keyword(s):  
Arabidopsis Thaliana ◽  
Multigene Family ◽  
Sequence Similarity ◽  
Plant Cells ◽  
The Family ◽  
Model Plant Arabidopsis Thaliana ◽  
Group 1 ◽  
Plant Arabidopsis Thaliana

Glycosyltransferases transfer sugars from NDP-sugar donors to acceptors. The multigene family of transferases described in this paper typically transfer glucose from UDP-glucose to low-molecular-mass acceptors in the cytosol of plant cells. There are 107 sequences in the genome of Arabidopsis thaliana that contain a consensus, suggesting they belong to this Group 1 multigene family. The family has been analysed phylogenetically, and a functional genomics approach has been applied to explore the relatedness of sequence similarity to catalytic specificity and stereoselectivity. Enzymes belonging to this class of transferases glycosylate a vast array of acceptors, including natural products such as secondary metabolites and hormones, as well as xenobiotics absorbed by the plant, such as herbicides and pesticides. Conjugation to glucose potentially changes the activity of the acceptor molecule and invariably changes its location within the plant cell. Using the genomics approach described, a platform of knowledge has been constructed that will enable an understanding to be gained on the role of these enzymes in cellular homoeostasis, as well as their activity in biotransformations in vitro that require strict regioselectivity of glycosylation.

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