scholarly journals Ascorbate concentration in Arabidopsis thaliana and expression of ascorbate related genes using RNAseq in response to light and the diurnal cycle

2017 ◽  
Author(s):  
William Laing ◽  
Cara Norling ◽  
Di Brewster ◽  
Michele Wright ◽  
Sean Bulley
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Transcriptional Regulation ◽  
Diurnal Cycle ◽  
Regulatory Gene ◽  
Time Of Day ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Ascorbate Concentration ◽  
Ascorbate Biosynthesis

AbstractWe explore where transcriptional regulation of ascorbate concentration lies in plants. Is it in biosynthesis,recycling, regulation or consumption? Arabidopsis thaliana plants were grown under controlled environment at four photon flux density levels (PFD). Rosettes from plants were harvested at the four PFD levels and over a diurnal cycle and after a step change in PFD and analysed for ascorbate concentration and transcript levels measured by RNAseq. Ascorbate concentrations and expression of genes in the L-galactose ascorbate biosynthesis, recycling,consumption pathways and regulation are presented to provide a full analysis of the control of ascorbate by environmentally modulated gene expression. Ascorbate concentration responded to PFD levels but not to time of day and showed only a small response to change of PFD after 2 days. Of the L-galactose pathway genes, only GDP galactose phosphorylase (GGP) showed a significant response in to different PFDs, time of day and to change in PFD. Other genes also showed limited responses. This study compares gene expression of a range of ascorbate related genes to changes in environment in a unified way and supports the concept that GGP is the key regulatory gene in ascorbate biosynthesis and that post transcriptional regulation is also important.HighlightIn a comprehensive study of expression of all ascorbate related genes the data is consistent with the control of leaf ascorbate concentration by transcription being through the expression of GDP galactose phosphorylase.

scholarly journals Time-Course of Changes in Photosynthesis and Secondary Metabolites in Canola (Brassica napus) Under Different UV-B Irradiation Levels in a Plant Factory With Artificial Light

2021 ◽  
Vol 12 ◽  
Author(s):  
Jin-Hui Lee ◽  
Seina Shibata ◽  
Eiji Goto
Keyword(s):  
Gene Expression ◽  
Time Course ◽  
Expression Patterns ◽  
Gene Location ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Total Phenolic ◽  
Artificial Light ◽  
Expression Levels ◽  
Plant Factory

This study aimed to evaluate short-duration (24 h) UV-B irradiation as a preharvest abiotic stressor in canola plants. Moreover, we quantified the expression levels of genes related to bioactive compounds synthesis in response to UV-B radiation. Canola seedlings were cultivated in a plant factory under artificial light (200 μmol m–2 s–1 photosynthetic photon flux density; white LED lamps; 16 h on/8 h off), 25°C/20°C daytime/nighttime air temperature, and 70% relative humidity. Eighteen days after sowing, the seedlings were subjected to supplemental UV-B treatment. The control plants received no UV-B irradiation. The plants were exposed to 3, 5, or 7 W m–2 UV-B irradiation. There were no significant differences in shoot fresh weight between the UV-B-irradiated and control plants. With increasing UV-B irradiation intensity and exposure time, the H2O2 content gradually increased, the expression levels of genes related to photosynthesis downregulated, and phenylpropanoid and flavonoid production, and also total phenolic, flavonoid, antioxidant, and anthocyanin concentrations were significantly enhanced. The genes related to secondary metabolite biosynthesis were immediately upregulated after UV-B irradiation. The relative gene expression patterns identified using qRT-PCR corroborated the variations in gene expression that were revealed using microarray analysis. The time point at which the genes were induced varied with the gene location along the biosynthetic pathway. To the best of our knowledge, this is the first study to demonstrate a temporal difference between the accumulation of antioxidants and the induction of genes related to the synthesis of this compound in UV-B-treated canola plants. Our results demonstrated that short-term UV-B irradiation could augment antioxidant biosynthesis in canola without sacrificing crop yield or quality.

Control of Flowering in Arabidopsis thaliana by Light, Vernalisation and Gibberellins

1992 ◽  
Vol 19 (4) ◽  
pp. 401 ◽  
Author(s):  
DJ Bagnall
Keyword(s):  
Arabidopsis Thaliana ◽  
Single Point ◽  
Red Light ◽  
Leaf Number ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Late Flowering ◽  
Subsequent Flowering ◽  
Incandescent Lamps ◽  
Short Days

The late flowering mutants of the Landsberg erecta race of Arabidopsis thaliana (L.) Heynh. were responsive to both vernalisation treatment and the ratio of red: far-red light (660 : 730 nm) with regard to time to flower and the numbers of leaves formed prior to flowering. The most vernalisation-sensitive mutants, fca, fve, fy and fpa, were also the most sensitive with regard to changes in the red:far-red light ratio. These responsive mutants flowered up to 40% earlier under lighting that included a greater proportion of far-red (730 nm) light from incandescent lamps compared with plants under light at the same photon flux density (PFD) with a greater proportion of energy from fluorescent lamps. Conversely, the mutants that were only slightly responsive to vernalisation (co, gi and fe) were also least responsive to changes in red:far-red ratio. The correlation between responsiveness to vernalisation and responsiveness to changes in red: far-red for the 11 mutants and Landsberg was highly significant (r2 = 0.88). Time to flower and leaf number at flowering were also markedly affected by changes in PFD in the vernalisation-sensitive mutants. Halving the PFD approximately doubled time-to-flower and leaf number of fca, the most responsive of the late flowering mutants, whereas there were only slight changes in the flowering responses of the parent Landsberg. Thus, these single point late flowering mutants are responsive not only to vernalisation but also to changes in light quality and PFD. These responses imply that both daylength perception and photosynthesis have been affected by the mutations. Gibberellins (GAS) induced earlier flowering not only in the late flowering mutant fca, but also in Landsberg, when that race was grown in short days. Dosages of 5 μg plant-1 of GA3, GA5 and GA9 were equaIly effective in promoting flowering of 15-day-old fca plants with subsequent flowering 9-13 days earlier with 4-6 fewer leaves. Photoperiodic sensitivity to a single long day 15 days after sowing showed Landsberg flowering 6 days earlier and with 1.4 fewer leaves than plants continuously in short days.

scholarly journals Instantaneous Light Measurements Predict Relative Cumulative Light Levels within an Apple Canopy

1992 ◽  
Vol 117 (4) ◽  
pp. 678-684 ◽  
Author(s):  
Richard J. Campbell ◽  
Richard P. Marini
Keyword(s):  
Predictive Models ◽  
Predictive Accuracy ◽  
Weather Condition ◽  
Growing Season ◽  
Photosynthetic Photon Flux Density ◽  
Time Of Day ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photon Density ◽  
Canopy Development

Percent instantaneous incident photosynthetic photon flux density (%INPPFD) was measured within an apple (Malus domestica Borkh.) canopy for various sky conditions and used to predict the percent cumulative incident photosynthetic photon density (PPD) for the last 10 weeks of the growing season (%CPPDLS) and the total growing season (%CPPDTS). Instantaneous measurements from overcast conditions were superior to measurements from clear or hazy conditions for the prediction of %CPPDLS in 1989 and 1990. A one-to-one relationship between %INPPFD and %CPPDLS was found for overcast conditions in both years, even though there was an 11% difference in total cumulative PPD between the years. The models had good predictive accuracy, with prediction coefficients of determination (R2Pred) >0.83 in both years (n = 30). %lNPPFD from overcast conditions also yielded accurate predictive models for %CPPDTS (R > 0.84, n = 30), which differed from the models for %CPPDLS. Predictive models (for both %CPPDLS and %CPPDTS) from %lNPPFD made before the canopy was fully developed differed from the models developed after canopy development was complete. The models still had good predictive accuracy, with R2Pred >0.76 (n = 30). Predictive models developed for cloudless conditions had inferior predictive accuracy (R2Pred = 0.49 to 0.80, n = 30) compared to models for overcast conditions. R2Pred were higher for hazy than for clear conditions. Time of day (1000 to 1400 hr) had no consistent effect on the development of predictive models for any weather condition. The most reliable models resulted from the average of several measurements within a day, particularly for cloudless conditions.

Interplay between Pur α and Egr-1 in the transcriptional regulation of amyloid precursor protein gene expression

2010 ◽  
Vol 34 (8) ◽  
pp. S27-S27
Author(s):  
Jianqi Cui ◽  
Xiuying Pei ◽  
Qian Zhang ◽  
Bassel E. Sawaya ◽  
Xiaohong Lu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcriptional Regulation ◽  
Amyloid Precursor Protein ◽  
Protein Gene ◽  
Precursor Protein ◽  
Amyloid Precursor Protein Gene
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