Cerium oxide nanoparticles (nCeO2 ) are interesting nanomaterials due to their redox properties. Their wide application could result in unexpected consequences to environmental safety. Unlike acute ...toxicity, the trans-generational effects of carbohydrate-coated nCeO2 in the environment are still unknown. The main aim of this study was to investigate the effect of treating maternal plants of Chenopodium rubrum L. (red goosefoot) and Sinapis alba L. (white mustard) with uncoated (CeO2 ) and glucose-, levan-, or pullulan-coated nCeO2 (G-, L-, or P-CeO2 ) during seed germination on morphological and physiological characteristics of produced seeds in two subsequent generations. The plant response was studied by measuring germination percentage (Ger), total protein content (TPC), total phenolic content (TPhC), total antioxidative activity (TAA), and catalase (CAT) activity. Results showed that maternal effects of the different nCeO2 treatments persist to at least the second generation in seeds. Generally, C. rubrum was more sensitive to nCeO2 treatments than S. alba . The coated nCeO2 were more effective than uncoated ones in both plant species; L- and P-CeO2 were the most effective in S. alba , while CeO2 and G-CeO2 had a dominant impact in C. rubrum . Enhanced germination in all tested generations of S. alba seeds recommends nCeO2 for seed priming.
Drought stress conditions modify source–sink relations, thereby influencing plant growth, adaptive responses, and consequently crop yield. Invertases are key metabolic enzymes regulating sink ...activity through the hydrolytic cleavage of sucrose into hexose monomers, thus playing a crucial role in plant growth and development. However, the physiological role of invertases during adaptation to abiotic stress conditions is not yet fully understood. Here it is shown that plant adaptation to drought stress can be markedly improved in tomato (Solanum lycopersicum L.) by overexpression of the cell wall invertase (cwInv) gene CIN1 from Chenopodium rubrum. CIN1 overexpression limited stomatal conductance under normal watering regimes, leading to reduced water consumption during the drought period, while photosynthetic activity was maintained. This caused a strong increase in water use efficiency (up to 50%), markedly improving water stress adaptation through an efficient physiological strategy of dehydration avoidance. Drought stress strongly reduced cwInv activity and induced its proteinaceous inhibitor in the leaves of the wild-type plants. However, the CIN1-overexpressing plants registered 3- to 6-fold higher cwInv activity in all analysed conditions. Surprisingly, the enhanced invertase activity did not result in increased hexose concentrations due to the activation of the metabolic carbohydrate fluxes, as reflected by the maintenance of the activity of key enzymes of primary metabolism and increased levels of sugar-phosphate intermediates under water deprivation. The induced sink metabolism in the leaves explained the maintenance of photosynthetic activity, delayed senescence, and increased source activity under drought stress. Moreover, CIN1 plants also presented a better control of production of reactive oxygen species and sustained membrane protection. Those metabolic changes conferred by CIN1 overexpression were accompanied by increases in the concentrations of the senescence-delaying hormone trans-zeatin and decreases in the senescence-inducing ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) in the leaves. Thus, cwInv critically functions at the integration point of metabolic, hormonal, and stress signals, providing a novel strategy to overcome drought-induced limitations to crop yield, without negatively affecting plant fitness under optimal growth conditions.
The transition from vegetative to reproductive phases is the most fundamental and tightly controlled switch in the life of flowering plants. The short-day plant Chenopodium rubrum is a fast cycling ...annual plant lacking a juvenile phase. It can be induced to flowering at the seedling stage by exposure to a single period of darkness. This floral induction may then be cancelled by a short pulse of red light at midnight called night break (NB), which also inhibits the floral activator FLOWERING LOCUS T LIKE 1 (CrFTL1). We performed a comparative transcriptomic study between C. rubrum seedlings treated by NB and ones growing through uninterrupted night, and found about six hundred differentially expressed genes, including the B-BOX DOMAIN (BBX) genes. We focused on the CrBBX19 and BOLTING TIME CONTROL 1 (BTC1) genes, homologous to the upstream regulators of the BvFT2, a floral inducer in sugar beet. The transcription patterns of the two genes were compatible with their putative role as a sensor of the dark period length optimal for flowering (CrBBX19), and a signal of lights-on (CrBTC1), but the participation of other genes cannot be excluded. The expression profiles of CrBBX19 and the homolog of the core endogenous clock gene LATE ELONGATED HYPOCOTYL (LHY) were highly similar, which suggested their co-regulation.
•Short pulse of red light (night break) deactivates floral induction in C. rubrum.•Night break affects expression of the CrBBX genes, including CrBBX19.•CrBBX19 and CrBTC1 are the orthologs of floral regulators in sugar beet.•CrBBX19 and CrBTC1 may be involved in floral induction in C. rubrum.•The homolog of the clock gene CrLHY is co-expressed with CrBBx19.
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► Plastid and nuclear data find Chenopodium s.l. as highly paraphyletic. ► Chenopodium s.l. comprises five well supported lineages. ► Two new lineages were found based on the broad ...taxonomic sampling. ► Chenopodium s str. can be well defined. ► Taxonomic and nomenclatural conclusions within Chenopodium are proposed.
Chenopodium is a large and morphologically variable genus of annual and perennial herbs with an almost global distribution. All subgenera and most sections of Chenopodium were sampled along with other genera of Chenopodieae, Atripliceae and Axyrideae across the subfamily Chenopodioideae (Chenopodiaceae), totalling to 140 taxa. Using Maximum parsimony and Bayesian analyses of the non-coding trnL-F (cpDNA) and nuclear ITS regions, we provide a comprehensive picture of relationships of Chenopodium sensu lato. The genus as broadly classified is highly paraphyletic within Chenopodioideae, consisting of five major clades. Compared to previous studies, the tribe Dysphanieae with three genera Dysphania, Teloxys and Suckleya (comprising the aromatic species of Chenopodium s.l.) is now shown to form one of the early branches in the tree of Chenopodioideae. We further recognize the tribe Spinacieae to include Spinacia, several species of Chenopodium, and the genera Monolepis and Scleroblitum. The Chenopodium rubrum and the Ch. murale-clades were newly discovered as distinct major lineages but their relationships within Chenopodioideae will need further evaluation. Based on our results, we suggest the delimitation of Chenopodium to include Einadia and Rhagodia because these are part of the crown group composed of species of subg. Chenopodium that appear sister to the Atripliceae. The tetraploid crops such as Ch. berlandieri subsp. nuttalliae and Ch. quinoa also belong to Chenopodium sensu stricto. Trees derived from trnL-F and ITS were incongruent within this shallow crown group clade. Possible biological causes are discussed, including allopolyploidization.
•We studied the effect of temperature, moisture and soil on seedling emergence of riparian plant species.•Response to the different temperature and moisture treatments was highly ...species-specific.•Seeds of some species that did not emerge might have become physiologically dormant partially.•Moisture conditions strongly affect the composition of the community that is establishing.•Sandy soil is less suitable for the restoration of riparian plant communities.
Restoration of riparian plant communities on bare soil requires germination of seeds and establishment of seedlings. However, species that are present in the soil seed bank do not always establish in the vegetation. Temperature, moisture conditions and soil type could play a major role in the establishment of riparian plant communities, through impacting seedling emergence.
We studied the effects of temperature, combinations of temperature and moisture conditions, and soil type on seedling emergence and mortality of perennial reeds (Typha latifolia and Phragmites australis) and annual or biannual pioneer species (Senecio congestus, Rumex maritimus and Chenopodium rubrum). The responses to the environmental conditions were species-specific and resulted in context-dependent differences in proportions of species emerging from the soil seed bank. Typha latifolia and S. congestus preferred wet or very wet conditions, C. rubrum and R. maritimus preferred dry to very dry conditions. Phragmites australis was able to establish under all conditions. Both cold and very dry conditions resulted in low emergence and survival, which was not fully compensated for when conditions became favorable again. Senecio congestus, R. maritimus and C. rubrum benefitted from secondary seedling emergence when, after a very dry period, the weather became very wet again, while T. latifolia and P. australis remained absent.
When the conditions remained wet, more seedlings emerged from sand than from clay. However, when the soil was drying out, fewer seedlings emerged from sand than from clay.
We propose that using information on plant species-specific responses to abiotic environmental conditions during germination, emergence and establishment can help to restore different target riparian plant communities.
A wheat stay-green mutant, tasg1, was observed to exhibit significantly delayed senescence in the late developmental stage. The photosynthetic capacity of the flag leaf was greater in tasg1 than in ...wild type (WT) plants. In addition, the grain volume of tasg1 was significantly higher than that of WT at the early filling stage. The content of various cytokinins (CKs) in the grain was significantly higher in tasg1 than in WT and was accompanied by an upregulated expression of some cell cycle-related genes. Examination of the metabolism of soluble sugars in tasg1 and WT revealed that the concentrations of glucose (Glu), fructose (Fru), and sucrose (Suc) were higher in the flag leaves and grains of tasg1 than in WT plants. The activities of sucrose-phosphate synthase (SPS), sucrose synthase (SuSy), and cell wall invertase (CW-invertase) were higher in tasg1, suggesting an altered metabolism and transport of soluble sugars. Furthermore, when tasg1 was treated with the CK inhibitor lovastatin, the activity of invertase was inhibited and was associated with premature senescence phenotype. However, the activity of invertase was partially recovered in tasg1 when treated with 6-benzylaminopurine (BAP). The trend of change in the concentrations of Glu, Fru, and Suc was similar to that of invertase. Our results suggest that CKs might regulate the stay-green phenotype of tasg1 by regulating the invertase activity involved in Suc remobilization.
Bacterial communities producing ectoine were studied in the rhizosphere of red goosefoot (
Chenopodium rubrum
L.) and weeping alkaligrass (
Puccinellia distans
(Jacq.) Parl.) growing on technogenic ...soil (Technosol) near the salt dump of the Solikamsk Potash Industrial Ore Administration 2 (SPIOA 2) of Uralkali PJSC (Solikamsk, Perm region) in order to assess the effect of this osmoprotective compound on plants under the conditions of technogenic salinization. It was found that most of bacteria in the studied soil are capable of synthesizing ectoine. The content of ectoine in the soil, as well as the number of producing bacteria, was higher in the rhizosphere than in the soil without plants. The concentration of ectoine was 167.4 ± 9.8 µmol/kg in the rhizosphere of red goosefoot, 92.9 ± 14.1 µmol/kg in the rhizosphere of weeping alkaligrass, and 23.9 ± 8.4 µmol/kg in the soil without plants. Bacteria belonging to the
Pseudomonas
genus predominated in the bacterial community of the rhizosphere of red goosefoot, and representatives of the
Halomonas
genus predominated in the rhizosphere of weeping alkaligrass. A stimulating effect on the growth of seedling roots under the conditions of salt stress was found for the following ectoine-producing strains:
Halomonas
sp. MK 2-1,
Pseudomonas
sp. BR 19-12, and
Dietzia
sp. PMK 9. The data obtained indicate the existence of positive effect of rhizosphere bacterial communities on plants under salinization due to the production of ectoine and may be used to develop biotechnologies that increase the productivity of plants growing on saline soils.
ABSTRACT
In recent years, the concept of shade avoidance has provided a functional meaning to the role of the phytochrome photoreceptor family in mature plants in their natural environment, and the ...question of which of these phytochromes is responsible for shade avoidance reactions has inevitably been raised. Unfortunately, a misconception has arisen that phytochrome B is solely responsible for detecting the environmental signal that initiates the shade avoidance syndrome. This view is too simplistic, and is based upon a selective interpretation of the available evidence. In this short Commentary, we review the concept of the shade avoidance syndrome, show how the misconception arose, and emphasize the plurality of perception and response that is crucial to successful competition for light.
Tanning sludge enriched with high concentrations of Cr and other metals has adverse effects on the environment. Plants growing in the metalliferous soils may have the ability to cope with high metal ...concentrations. This study focuses on potentials of using native plants for bioindication and/or phytoremediation of Cr-contaminated sites. In the study, we characterized plants and soils from six tanning sludge storage sites. Soil in these sites exhibited toxic levels of Cr (averaged 16,492 mg kg
−1
) and other metals (e.g., 48.3 mg Cu kg
−1
, 2370 mg Zn kg
−1
, 44.9 mg Pb kg
−1
, and 0.59 mg Cd kg
−1
). Different metal tolerance and accumulation patterns were observed among the sampled plant species.
Phragmites australis
,
Zephyranthes candida
,
Cynodon dactylon
, and
Alternanthera philoxeroides
accumulated moderate-high concentrations of Cr and other metals, which could make them good bioindicators of heavy metal pollution. High Cr and other metal concentrations (e.g., Cd and Pb) were found in
Chenopodium rubrum
(372 mg Cr kg
−1
),
Aster subulatus
(310 mg Cr kg
−1
), and
Brassica chinensis
(300 mg Cr kg
−1
), being considered as metal accumulators. In addition,
Nerium indicum
and
Z. candida
were able to tolerate high concentrations of Cr and other metals, and they may be used as preferable pioneer species to grow or use for restoration in Cr-contaminated sites. This study can be useful for establishing guidelines to select the most suitable plant species to revegetate and remediate metals in tanning sludge-contaminated fields.
The phenolic acids content of methanolic extracts before and after acidic hydrolysis of different morphological parts of Chenopodium rubrum was determined by LC-ESI-MS/MS. Overall eleven phenolic ...acids were detected and quantified. The most common were p-coumaric, ferulic and salicylic acids, which were present in all analyzed extracts. Gallic, caffeic, vanillic, syringic and sinapic acids were found in bound forms. Gentisic acid was most abundant in roots (3.7 mg/100g d.w.), syringic acid in stalks (2.9 mg/100 g d.w.), ferulic acid in leaves (6.0 mg/100g d.w.), and protocatechuic acid in seeds (2.3 mg/100g d.w.). The highest concentration of examined acids was found in leaves (19.1 mg/100g d.w.) and roots (10.0 mg/100g d.w.). Cytotoxic activity of extracts was tested against human cancer cell lines HTB 140, WM 793, Du 145 and normal PNT2 cells. Only the seed extract showed activity against malignant melanoma WM 793 cell line (69.6 ± 0.7% of dead cells at 100 μg/mL).
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