Retrograde signalling from the mitochondria to the nucleus translates the positive effect of ethylene on dormancy breaking of Arabidopsis thaliana seeds

2020 ◽  
Author(s):  
Rana Jurdak ◽  
Alexandra Launay‐Avon ◽  
Christine Paysant‐Le Roux ◽  
Christophe Bailly
Keyword(s):  
Arabidopsis Thaliana ◽  
Dormancy Breaking ◽  
Retrograde Signalling ◽  
Positive Effect

scholarly journals Proteomic analysis of haem-binding protein from Arabidopsis thaliana and Cyanidioschyzon merolae

2020 ◽  
Vol 375 (1801) ◽  
pp. 20190488 ◽  
Author(s):  
Takayuki Shimizu ◽  
Rintaro Yasuda ◽  
Yui Mukai ◽  
Ryo Tanoue ◽  
Tomohiro Shimada ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Proteomic Analysis ◽  
High Performance ◽  
Biochemical Analysis ◽  
Cyanidioschyzon Merolae ◽  
Genes Expression ◽  
Retrograde Signalling ◽  
Coordinated Expression ◽  
Retrograde Signal ◽  
Affinity Beads

Chloroplast biogenesis involves the coordinated expression of the plastid and nuclear genomes, requiring information to be sent from the nucleus to the developing chloroplasts and vice versa. Although it is well known how the nucleus controls chloroplast development, it is still poorly understood how the plastid communicates with the nucleus. Currently, haem is proposed as a plastid-to-nucleus (retrograde) signal that is involved in various physiological regulations, such as photosynthesis-associated nuclear genes expression and cell cycle in plants and algae. However, components that transduce haem-dependent signalling are still unidentified. In this study, by using haem-immobilized high-performance affinity beads, we performed proteomic analysis of haem-binding proteins from Arabidopsis thaliana and Cyanidioschyzon merolae . Most of the identified proteins were non-canonical haemoproteins localized in various organelles. Interestingly, half of the identified proteins were nucleus proteins, some of them have a similar function or localization in either or both organisms. Following biochemical analysis of selective proteins demonstrated haem binding. This study firstly demonstrates that nucleus proteins in plant and algae show haem-binding properties. This article is part of the theme issue ‘Retrograde signalling from endosymbiotic organelles’.

scholarly journals Graphene Oxide-Assisted Promotion of Plant Growth and Stability

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 758 ◽  
Author(s):  
Sunho Park ◽  
Kyoung Soon Choi ◽  
Sujin Kim ◽  
Yonghyun Gwon ◽  
Jangho Kim
Keyword(s):  
Arabidopsis Thaliana ◽  
Graphene Oxide ◽  
Plant Growth ◽  
Growth Medium ◽  
Fruit Ripening ◽  
Sugar Content ◽  
Flower Buds ◽  
Ripening Process ◽  
Number Of Leaves ◽  
Positive Effect

The control and promotion of plant and crop growth are important challenges globally. In this study, we have developed a nanomaterial-assisted bionic strategy for accelerating plant growth. Although nanomaterials have been shown to be toxic to plants, we demonstrate herein that graphene oxide can be used as a regulator tool for enhancing plant growth and stability. Graphene oxide was added to the growth medium of Arabidopsis thaliana L. as well as injected into the stem of the watermelon plant. We showed that with an appropriate amount provided, graphene oxide had a positive effect on plant growth in terms of increasing the length of roots, the area of leaves, the number of leaves, and the formation of flower buds. In addition, graphene oxide affected the watermelon ripeness, increasing the perimeter and sugar content of the fruit. We believe that graphene oxide may be used as a strategy for enabling the acceleration of both plant growth and the fruit ripening process.

scholarly journals AtRsgA from Arabidopsis thaliana controls maturation of the small subunit of the chloroplast ribosome

2017 ◽  
Author(s):  
Marcin Janowski ◽  
Reimo Zoschke ◽  
Lars Scharff ◽  
Silvia Martinez Jaime ◽  
Camilla Ferrari ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Proteomic Analysis ◽  
Ribosome Biogenesis ◽  
Functional Characterization ◽  
Small Subunit ◽  
Signalling Pathways ◽  
Compensatory Mechanism ◽  
Transcriptional Responses ◽  
Retrograde Signalling ◽  
Assembly Factor

SummaryPlastid ribosomes are very similar in structure and function to ribosomes of their bacterial ancestors. Since ribosome biogenesis is not thermodynamically favourable at biological conditions, it requires activity of many assembly factors. Here, we have characterized a homolog of bacterial rsgA in Arabidopsis thaliana and show that it can complement the bacterial homolog. Functional characterization of a strong mutant in Arabidopsis revealed that the protein is essential for plant viability, while a weak mutant produced dwarf, chlorotic plants that incorporated immature pre-16S ribosomal RNA into translating ribosomes. Physiological analysis of the mutant plants revealed smaller, but more numerous chloroplasts in the mesophyll cells, reduction of chlorophyll a and b, depletion of proplastids from the rib meristem and decreased photosynthetic electron transport rate and efficiency. Comparative RNA-sequencing and proteomic analysis of the weak mutant and wild-type plants revealed that various biotic stress-related, transcriptional regulation and post-transcriptional modification pathways were repressed in the mutant. Intriguingly, while nuclear- and chloroplast-encoded photosynthesis-related proteins were less abundant in the mutant, the corresponding transcripts were upregulated, suggesting an elaborate compensatory mechanism, potentially via differentially active retrograde signalling pathways. To conclude, this study reveals a new chloroplast ribosome assembly factor and outlines the transcriptomic and proteomic responses of the compensatory mechanism activated during decreased chloroplast function.Significance statementAtRsgA is an assembly factor necessary for maturation of the small subunit of the chloroplast ribosome. Depletion of AtRsgA leads to dwarfed, chlorotic plants and smaller, but more numerous chloroplasts. Large-scale transcriptomic and proteomic analysis revealed that chloroplast-encoded and - targeted proteins were less abundant, while the corresponding transcripts were upregulated in the mutant. We analyse the transcriptional responses of several retrograde signalling pathways to suggest a mechanism underlying this compensatory response.

Rooting of cuttings of Passiflora suberosa, a medicinal passion fruit species: characterization and modulation by external biochemical factors

2020 ◽  
Vol 67 (1-2) ◽  
pp. 40-51
Author(s):  
Johnatan Vilasboa ◽  
Cibele Tesser da Costa ◽  
Hélio Nitta Matsuura ◽  
Arthur Germano Fett-Neto
Keyword(s):  
Peroxidase Activity ◽  
Bioactive Compound ◽  
Adventitious Rooting ◽  
Culture Solution ◽  
Full Potential ◽  
Dormancy Breaking ◽  
Fruit Species ◽  
Rooting Of Cuttings ◽  
Medicinal Properties ◽  
Positive Effect

Passiflora suberosa L. (Passifloraceae) can be found throughout the Americas, and has several medicinal properties, including antioxidant, antibacterial, anti-hemolytic, hypolipidemic, and hypoglycemic activities. Germination rates of P. suberosa are low, even with dormancy breaking treatments, posing an obstacle for its multiplication. Vegetative propagation is a valuable approach to produce clones of elite individuals with important pharmacological characteristics, affording fast genetic improvement of biomass source for both phytomedicine manufacturing and bioactive compound isolation. Understanding the rooting process of this species is an important step to exploit its full potential in a sustainable way. We investigated adventitious rooting (AR) in absence or presence of exogenous auxin in P. suberosa cuttings, using a non-aerated hydroponic system. Changes in concentration of flavonoids, phenolics, hexoses, starch, and auxin, as well as peroxidase activity, were monitored along AR. Cuttings showed spontaneous rooting, although the application of exogenous indole-3-butyric acid (IBA) yielded higher number of shorter roots. Biochemical parameters, mainly concentration of carbohydrates and total phenolics, as well as peroxidase activity, varied along the course of the experiments. Based on these results, attempts were made to up- or down-modulate rooting responses by applying putative regulators to the growth solution at different time points. It was possible to block the positive effect of auxin on root development, with only minor positive impacts on the modulated control devoid of auxin. Overall analyses suggested that the rooting system proved effective and specific peroxidase activity showed partial correlation with AR, being able to suffer modulation by culture solution factors.

scholarly journals Effects of different treatments on seed dormancy breaking and germination in Acer cappadocicum Gleditsch var. cappadocicum

2020 ◽  
Vol 144 (3-4) ◽  
pp. 159-166
Author(s):  
Hanife Erdogan Genç ◽  
Ali Ömer Üçler
Keyword(s):  
Seed Germination ◽  
Seed Dormancy ◽  
Germination Percentage ◽  
Growth Chamber ◽  
Dormancy Breaking ◽  
Seed Collection ◽  
Physiological Dormancy ◽  
Germination Value ◽  
Positive Effect ◽  
Collection Time

This study was carried out to determine effects of different pretreatment on seed germination and to overcome dormancy in Acer cappadocicum seeds. The seeds were collected in 2008 three times with aproximately 15-days intervals. In order to overcome dormancy, several germination treatments were applied. The treatments were (1) different seed collection time, (2)soaking in water, (3) cold-moist stratification and (4) GA<sub>3</sub> (gibberellic acid) application. The treated seeds were germinated in growing chamber at 5 <sup>0</sup>C and in greenhouse conditions. This research showed that seeds of Acer cappadocicum exhibit physiological dormancy and require stratification period to overcome seed dormancy. The highest germination percentage in the growing chamber subjected to GA<sub>3</sub> process after eight weeks of stratification treatment was 62 % for Acer cappadocicum seeds. The highest germination percentage in greenhouse was obtained with cold stratification after eight weeks (95 %). It was found out that GA<sub>3</sub> treatment had a significant effect on germination in growth chamber + 5 <sup>0</sup>C but GA<sub>3</sub> treatment didn’t have a significant effect on germination in greenhouse conditions. GA<sub>3</sub> treatment and soaking of unstratified seeds in water for 48 hr didn’t have any positive effect on germination value in greenhouse conditions. Although growth chamber and green house results both indicated that seed collection time did not seem to play a role as statistically on seed germination, Duncan’s test showed that the third seed collection time was in a different group.

scholarly journals Inhibitor-induced oxidation of the nucleus and cytosol in Arabidopsis thaliana: implications for organelle to nucleus retrograde signalling

2017 ◽  
Vol 372 (1730) ◽  
pp. 20160392 ◽  
Author(s):  
Barbara Karpinska ◽  
Sarah Owdah Alomrani ◽  
Christine H. Foyer
Keyword(s):  
Arabidopsis Thaliana ◽  
Redox State ◽  
Guard Cells ◽  
Signalling Pathways ◽  
Mrna Levels ◽  
Cellular Redox ◽  
Mitochondrial Inhibitors ◽  
Retrograde Signalling ◽  
Stomatal Guard Cells ◽  
Cellular Redox State

Concepts of organelle-to-nucleus signalling pathways are largely based on genetic screens involving inhibitors of chloroplast and mitochondrial functions such as norflurazon, lincomycin (LINC), antimycin A (ANT) and salicylhydroxamic acid. These inhibitors favour enhanced cellular oxidation, but their precise effects on the cellular redox state are unknown. Using the in vivo reduction–oxidation (redox) reporter, roGFP2, inhibitor-induced changes in the glutathione redox potentials of the nuclei and cytosol were measured in Arabidopsis thaliana root, epidermal and stomatal guard cells, together with the expression of nuclear-encoded chloroplast and mitochondrial marker genes. All the chloroplast and mitochondrial inhibitors increased the degree of oxidation in the nuclei and cytosol. However, inhibitor-induced oxidation was less marked in stomatal guard cells than in epidermal or root cells. Moreover, LINC and ANT caused a greater oxidation of guard cell nuclei than the cytosol. Chloroplast and mitochondrial inhibitors significantly decreased the abundance of LHCA1 and LHCB1 transcripts. The levels of WHY1 , WHY3 and LEA5 transcripts were increased in the presence of inhibitors. Chloroplast inhibitors decreased AOXA1 mRNA levels, while mitochondrial inhibitors had the opposite effect. Inhibitors that are used to characterize retrograde signalling pathways therefore have similar general effects on cellular redox state and gene expression. This article is part of the themed issue ‘Enhancing photosynthesis in crop plants: targets for improvement’.

The role of phytochrome C in gravitropism and phototropism in Arabidopsis thaliana

2008 ◽  
Vol 35 (4) ◽  
pp. 298 ◽  
Author(s):  
Prem Kumar ◽  
Crystal E. Montgomery ◽  
John Z. Kiss
Keyword(s):  
Arabidopsis Thaliana ◽  
Blue Light ◽  
Leaf Morphology ◽  
Red Light ◽  
Phytochrome A ◽  
Inflorescence Stems ◽  
Root Gravitropism ◽  
Positive Effect ◽  
Rosette Leaf

The phytochrome (phy) photoreceptors, which consist of a small gene family PHYA-E in dicot plants, play important roles in regulating many light-induced responses in plants. Although the best characterised phytochromes are phytochrome A (phyA) and phytochrome (phyB), the functions of phyD and phyE have been increasingly studied. Phytochrome C (phy C) has been the most poorly understood member of the photoreceptor family, since isolation of phyC mutants only has been accomplished within the last few years. Recent reports show that phyC functions in hypocotyl elongation, rosette leaf morphology, and timing of flowering. In the present study, we show that phyC plays a role in tropisms in seedlings and inflorescence stems of light-grown Arabidopsis thaliana (L.) Heynh. (Wassilewskija ecotype). Phytochrome C has a positive effect on gravitropism in hypocotyls and stems, but it has a limited role in root gravitropism. In contrast, phyC attenuates the positive phototropic response to blue light in hypocotyls and the red-light-based positive phototropism in roots. Phytochrome D (phy D) also mediates gravitropism in hypocotyls and inflorescence stems and attenuates positive phototropism in response to blue in hypocotyls and stems. Thus, phyC can be added to the list of the other four phytochromes, which play various roles in both gravitropism and phototropism in plant organs. This report also supports the growing body of evidence demonstrating cross talk between phytochromes and blue-light photoreceptors.

Thermal thresholds for seed germination in Mediterranean species are higher in mountain compared with lowland areas

2018 ◽  
Vol 29 (1) ◽  
pp. 44-54 ◽  
Author(s):  
Rosangela Picciau ◽  
Hugh W. Pritchard ◽  
Efisio Mattana ◽  
Gianluigi Bacchetta
Keyword(s):  
Seed Germination ◽  
Sea Level ◽  
Dormancy Breaking ◽  
Mediterranean Species ◽  
Thermal Thresholds ◽  
Data Loggers ◽  
Soil Temperatures ◽  
Germination Timing ◽  
Positive Effect ◽  
Neutral Effect

AbstractEach taxon is characterized by a temperature range over which seed germination is possible and this may vary in space and time in relation to climate and ecological conditions. We used thermal modelling to test the hypothesis that thermal thresholds for seed germination can predict germination timing of Mediterranean species along an altitudinal and environmental gradient. Seeds of 18 species were collected in Sardinia from sea level to 1810 m above sea level, and germination tests were carried out at a range of constant (5 to 25°C) and alternating (25/10°C) temperatures. Different dormancy-breaking treatments [gibberellic acid (GA3), cold (C) and warm (W) stratifications and dry after ripening (DAR)] were applied. The annual pattern of soil temperatures was recorded using 24 data-loggers buried close to the study species. The logged soil temperatures distinguished ‘Mediterranean lowland’ from ‘Mediterranean mountain’ species. Although germination was >50% in untreated seeds of most species, GA3 had a positive effect in all species. C either inhibited or had a neutral effect on germination, W did not enhanced seed germination, while DAR had a positive effect only in species from coastal environments. The thermal time constant (S) for 50% germination ranged from 22 to 357°Cd (degree days) above base temperatures (Tb) of –9 to 9°C, depending on species and treatments. Mediterranean lowland species had lower Tb values compared with upland species. This study revealed significant differences in germination thresholds of Mediterranean lowland and mountain species in relation to Tb and S that probably have an impact on germination timing in the field and niche competitiveness.

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