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Despite the accumulating evidence showing the essential role of pentatricopeptide repeat (PPR) proteins in organellar biogenesis and plant development in Arabidopsis thaliana and maize (Zea mays), the functions of most PPR proteins in rice (Oryza sativa) are still unknown. A former study demonstrated that the mitochondria-localized Arabidopsis PPR19 is crucial for mitochondrial function and normal plant growth and development. In this study, we characterized the functional role of a rice ortholog (LOC_Os12g04110) of Arabidopsis PPR19 protein. The loss-of-function osppr19 mutant displayed delayed seed germination and stunted root and seedling growth compared with wild-type. The height of the osppr19 mutant was significantly shorter, and the grain mass of the mutant was lower than that of the wild-type. The osppr19 mutant carried few filled grains and a higher number of aborted seeds than the wild-type. The structures of mitochondria in the osppr19 mutant were abnormal, and more reactive oxygen species were accumulated in the mutant, suggesting defective mitochondrial biogenesis and function in the osppr19 mutant. Importantly, the amount of mature mitochondrial transcripts was significantly decreased in the mutant. Taken together, these results suggest that the mitochondrial OsPPR19 is essential for mitochondrial biogenesis and function, which is crucial for plant growth and development of rice grain.

Strigolactones (SL) are crucial plant hormones that regulate plant growth. We investigated genetic and metabolic changes in tobacco axillary flower buds following application of GR24 (SL synthetic analogue), administered 2 and 6 days later. The results indicated that GR24 effectively inhibited the growth of axillary buds. RNA sequencing revealed 1 781 differentially expressed genes in axillary buds after 6 days of GR24 treatment compared to untreated controls. Among them, 882 genes were up-regulated following GR24 treatment, suggesting substantial number of genes experienced significant changes in expression following GR24 treatment. Four carbohydrate metabolites exhibited altered abundance after 6 days of GR24 treatment; one increased and three decreased. In this study, GR24 induces substantial changes in the transcriptome and metabolome of tobacco axillary buds, with the starch and sucrose metabolic pathways and the phenylpropane biosynthesis pathway playing essential roles in the regulation of tobacco axillary bud development. Transcriptomic and metabolomic analyses highlighted that GR24 treatment significantly modulated the starch and sucrose metabolic pathways and the phenylpropane biosynthesis pathway. Our results suggest that the metabolic pathways of starch and sucrose and the biosynthesis pathway of phenylpropane play important roles in the regulation of growth and development of tobacco axillary buds by GR24.

Phosphorus is a key limiting factor for plant growth. Several approaches are developed to mitigate the impact of P shortage on plants and to the selection of crops with high P mobilizing capacity from P-deficient soils. In this work, four Medicago truncatula genotypes (A17, TN8.20, TN1.11, and TN6.18) were compared for their efficiency to cope with P limiting conditions using several criteria. Significant differences between genotypes, P deficiency treatments, and the interaction of genotypes with P deficiency treatments were found. P limitation resulted in an important decrease in shoot biomass, P content, P use efficiency, and photosynthetic parameters. A significant variability was found between the four genotypes, with A17 and TN8.20 being the most tolerant genotypes to P deficiency. This was consistent with the better ability of these genotypes to acidify rhizosphere and stimulate the activity of acid phosphatase and its relative gene (MtPAP1). The expression of P transporter genes (MtPT1, MtPT3, and MtPT5) was induced by P deficiency, however, the overexpression of those genes was more pronounced in tolerant genotypes. Overall, our data indicate that A17 and TN8.20 are more efficient in mobilizing P under limiting conditions and could be cultivated in P-deficient soils as forage crops.

The intensification of agriculture is closely linked to high emissions of greenhouse gases. To address the challenges, the European Commission published the European Green Deal in 2019. The aim of our study was to compare the yield of maize genotypes bred in Martonvásár in three different cropping environments (organic, irrigated conventional, and non-irrigated conventional). The silage and grain yields of different maize hybrids and parental lines were evaluated in a three-replicate small plot experiments. The green mass yield of the organic area was 19 and 15% lower compared to the irrigated conventional and non-irrigated conventional treatments. The dry matter yield of the maize hybrids was 12.9 t ha-1 in the organic area, 15.7 t ha-1 in the irrigated, and 15.8 t ha-1 in the non-irrigated environment. Hybrids had significantly better grain yield in the conventional systems (irrigated: 10.0 t ha-1 and non-irrigated: 9.8 t ha-1) than in the organic environment (7.6 t ha-1). The difference in yield results was not as considerable for the parental lines as for the hybrids. In addition, our results indicated high presence of heterosis for yields. The heterosis of the grain yields was two times higher than for silage yields. Heterosis was highest at the non-irrigated conventional area.

Perennial ryegrass (PRG; Lolium perenne) remains the backbone of grass swards in Northern Ireland due to its improved digestibility persistence, and ease of management compared with other grass species. However, innovative breeding approaches are needed that include positive environmental outcomes, as well as improved productivity in ruminants. The objective of this study was to evaluate the feasibility of root-trait screening and selection using the in situ coring method under commercial grass breeding field conditions. 108 root cores were sampled over a 2-year period from a field trial sown in autumn 2021. Root cores were washed, scanned, and analysed using the open-access root scanning platform Rhizovision. A seasonal effect was noted whereby significant differences were detected in October for root volume, network area, and surface area, but no significant differences for any root parameter were detected in April. No association was observed between root volume, network area, or surface area at the October sampling with either dry matter (DM) yield at the 4th cut (October) or annual DM yield. These results suggest that this method may be useful for identifying improved germplasm in PRG for root characteristics; however, being comparatively labour and time intensive this method may not be practicable for large-scale breeding programmes.

Pod shattering is an undesirable process leading to loss of harvestable yields. In the present study, we sought to undertake the first comprehensive phenotyping in 254 bean (Phaseolus vulgaris L.) genotypes for pod shattering including various mechanistic aspects as well as assess natural variation in the germplasm set for 16 seed physical traits including shattering score. There was substantial variability in 16 pod physical traits in the material. Significant diversity of the material in respect of pod traits was indicated by the broad range and coefficient of variation (CV) values. Using Random Impact Assessment (RIA), we found substantial variability in pod shattering score in common bean genotypes indicating significant diversity. Shattering score had a mean value of 6.098 with a range of 1.07 to 9.13. Highest shattering score was recorded in WB-6, WB-20-247, and N-7 while the lowest value for shattering score was recorded in WB-1129 and WB-216. Shattering score was negatively correlated with pod thickness (r = -0.698) followed by ventral/dorsal length ratio (r = -0.468) and positively correlated with breadth/thickness ratio (r = 0.599) and string % (r = 0.590). The principal component analysis (PCA) concentrated 86.91% variability in the first five principal components, and the first two PCs accounted for 55.62% of the total variation.

An untargeted metabolomic analysis of five Eucalyptus species was used to compare their chemical profiles. Gas chromatography-mass spectrometry (GC-MS) along with multivariate analyses including principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied to assess variations in the leaf chemical profiles of E. maidenii F. Muell, E. robusta Smith, E. citriodora Hook (syn Corymbia citriodora), E. tereticornis Smith and E. camaldulensis Dehnh. In total, 299 relevant metabolites were identified and subjected to statistical analyses in order to detect either the major common metabolites of the genus or the specific compounds contributing to the characteristic chemical composition of each species. Organic acids, nitrogenous compounds, and phenolic constituents were the main discriminatory groups between the investigated eucalypts. The cluster analysis revealed that fatty acids and fatty alcohols were more concentrated in the leaves of E. citriodora and distinguished it from other species, whereas sugars, polyols, and glycosides were characteristic to E. camaldulensis.

Excess water is an abiotic stress in plants, but the level at which excess water becomes varies widely between plant species. We conducted a two growing season replicated excess flooding experiment that was planted with 24 accessions of perennial ryegrass which had been vegetatively propagated to ensure equal representation of genotypes within an accession, both cultivars and ecotypes, from various geographical origins. The excess water treatment applied over the winter periods was achieved with irrigation. Yields increased in the winter-flooded treatment in contrast to the non-artificial watered control treatment significantly in 2017. In 2018 the same trend could be seen, but was not significant. Differences in composition of macro- and micronutrient profiles were observed. Sulphur was the only element with highly significantly increased concentration (0.25%) in flooded samples compared to control. Phosphorus, copper, iron, manganese, and molybdenum decreased statistically significantly under flooded conditions. In conclusion, perennial ryegrass is coping extremely well with excess water supplied over the winter period and can utilise it effectively in spring.

In plant breeding, polyploidization is an established technique to obtain superior phenotypic characteristics. In seed propagated agricultural crops, seed treatments with antimitotic agents are often used to obtain chromosome doubling. Here, we developed a method to induce polyploidization in clonally propagated fodder grasses Lolium, Festuca, and the intergeneric hybrid Festulolium. The aim was to obtain specific genotypes at both the diploid and tetraploid levels. We evaluated different types of plant explants, and the effects of the type, concentration, and application mode of three antimitotic agents (oryzalin, colchicine, and trifluralin) on the survival rate and the polyploidization efficiency. The treatment of greenhouse-grown tillers with antimitotics only resulted in mixoploids, while tissue culture propagated plants were successfully polyploidized. A shock pretreatment, using a high concentration of an antimitotic agent during a short period, successfully induced tetraploids in all three genera. Additionally, supplementing the tissue culture medium with a lower dosage of an antimitotic agent during minimal four weeks after the shock pretreatment further promoted polyploidization. By our methods, we were able to generate diploid and tetraploid plants with an identical genomic constitution but different ploidy allowing investigation of the effects of polyploidization on plant physiology and gene regulatory networks.

Opportunities exist to accelerate genetic gain in forage breeding using genome-wide selection approaches. In this study, we evaluated rapid cycle recurrent genomic selection (GS) as a means of improving genetic gain for value of annual forage yield. A small population of tetraploid half-sib families was evaluated for seasonal forage yield over two years, and the maternal parent plants were genotyped and genomic prediction models developed. The GS model for value of annual forage yield had a predictive ability of 0.23. An initial round of among-family selection based on field evaluations and within-family selection using genomic estimated breeding values was performed. This was followed by two further GS cycles. New synthetics were produced after each round of selection and were established in a field trial alongside the starting population. A positive response to selection was observed in new synthetics after two successive rounds of rapid cycle recurrent genomic selection before declining in the third round. The genetic gain for the value of annual forage yield was 2.4% from C0 SYN-1 to C1 SYN-1 and 6.4% from C1 SYN-1 to C2 SYN-1. In the case of C0 to C1, genetic gain was compounded by among-family selection based on field evaluations. The implementation of rapid cycle recurrent genomic selection offers an opportunity to increase genetic gain; however, the predictive ability is likely to decay rapidly as selection candidates become more distant from the training population.

Martaban camphor [Cinnamomum parthenoxylon (Jack) Meisn] is a woody tree in India, China, Indonesia, Thailand, and Vietnam and has been widely utilized for commercial purposes. It is threatened due to fragmented habitats, over-deforestation, and oil extraction. To conserve this species, the investigation of genetic diversity and population structure of this species is essential. Herein, we analyzed 192 adult trees from eight populations covering its natural distribution range in Vietnam using ten polymorphic EST-SSR markers. Medium levels of genetic diversity (R = 2.7, Ho = 0.399, He = 0.426) and genetic differences between populations (Fst = 0.223) were determined. Two populations, Cuc Phuong and Xuan Nha have undergone recent bottlenecks. These results indicated that anthropogenic activities may be the major factor for the low heterozygosity and influenced the number of alleles in all C. parthenoxylon populations. Clustering analyses revealed three genetic clusters that related to gene flow between different areas. We proposed in situ conservation for some populations with high levels of allelic richness, genetic diversity, or private alleles. The collecting of the seeds of the remaining populations for ex-situ conservation could be performed.

The coastal areas of western Taiwan feature acidic and saline soils with low fertility. Sodium bicarbonate (NaHCO3), produced readily by carbon capture and storage technologies, could be suitable for the neutralization of acidic soils, but its effects on plant growth and the ability of Bacillus subtilis var. natto to confer salinity tolerance remain unclear. In this study, we examined the potential of sodium bicarbonate and B. subtilis var. natto (NTU18) to improve the growth of tobacco (Nicotiana tabacum L.) under salt stress conditions. We found that salt stress was the main factor affecting tobacco growth, resulting in shorter roots and shoots, a reduced leaf area and leaf number, and clustered dark green leaves. The addition of sodium bicarbonate exacerbated the symptoms of salinity stress. Inoculating the soil with B. subtilis did not enhance salinity tolerance, but intriguingly it increased shoot and root growth under normal conditions and in the presence of sodium bicarbonate. The mechanism of growth promotion mediated by the bacteria is unknown and should be investigated in more detail.

Flavonoids are a class of phenolic compounds that are widely distributed in nature. They have a variety of physiological and pharmacological activities. They exist in free form or in the form of glycosides. The glycosylation occurs by glycosyltransferases, which is a common modification of plant secondary metabolites and the last step of their biosynthesis. Glycosylation can increase the diversity of the structure and function of flavonoids, and is currently a research hotspot. Based on the classification of flavonoids, this paper describes and summarizes the biotransformation and characteristics of glycosylation modification of flavonoids with different structural types, and describes the effects of enzymatic glycosylation using different types of glycosyltransferases on the biological activity and function of flavonoids depending on sugar connection position, sugar quantity, and type. This paper provides a reference for the development and application of flavonoids glycosylation and glycosyltransferases and also opens up a new direction for plant breeding.

Lettuce is one of our most important leaf vegetables that can be cultivated safely in organic farming, which is not only pesticide-free, but also aims to maintain and stimulate the presence of naturally occurring beneficial organisms, such as algae, mosses, bacteria, or arbuscular mycorrhiza (AM) fungi. These organisms are all beneficial for soil life and nutrient decomposition. The positive effects of beneficial microorganisms could be enhanced by mulching which is a widely used practice in organic farming. Mulching may also increase soil nutrient substance after decomposition and inhibit weed growth. In our experiment, we sought to determine the effect of different mulching techniques (alfalfa, rye, black foil) on AM root colonisation, leaf chlorophyll (Chl) content, and on peroxidase (POD) activity in Lactuca sativa plants and observe whether there are correlations between these parameters. Results show natural mulching has a positive effect on mycorrhiza fungi root colonisation and therefore lowers the stress in lettuce plant. On the other hand, there was no significant correlation between root colonisation and Chl content. As POD enzymes are directly linked to enzymatic browning, the high colonisation rate of AM may consequently lower post-harvest browning in lettuce.

This study aimed to evaluate the effect of putrescine priming on the initial growth, chlorophyll fluorescence, primary metabolites accumulation, and antioxidant enzyme activities in two maize hybrids with contrasting drought tolerances. Seeds of Zea mays L. hybrids DKB 390 (drought tolerant) and BRS 1030 (drought sensitive) were primed with putrescine (10 or 100 µM). Paper rolls moistened with distilled water or mannitol (-0.6 MPa) were maintened at 30°C for 7 d. The growth parameters were higher in the DKB hybrid than in the BRS hybrid. Putrescine priming (10 µM) promoted the root growth of BRS at levels similar to those of DKB and improved photochemical and non-photochemical quenching and maximum quantum efficiency of BRS seedlings. Higher levels of reducing sugars were found in DKB seedlings when compared to BRS in both roots and leaves, especially with 100 µM putrescine. Total soluble sugar and starch were lower in the maize roots under water deficit and with 10 µM putrescine for both hybrids. BRS seedlings showed higher starch content in the leaves in the control and 10 µM putrescine treatments. Superoxide dismutase was activated in BRS plants by the priming, especially in the roots, but this effect was not observed for catalase, ascorbate, or guaiacol peroxidase, although the DKB seedlings presented much higher guaiacol peroxidade activity than BRS seedlings in both the roots and shoots. In conclusion, putrescine priming (10 M) improved the morphological and biochemical responses of the drought sensitive maize hybrid BRS.

Dendrobium williamsonii and Dendrobium cariniferum (Orchidaceae) are endangered perennial herbs, and they are very similar in morphology. Chloroplast genome sequencing technology provides a powerful tool for molecular analysis to get more infomation for phylogenetic analysis and identification of Dendrobium species. In this study, the complete chloroplast genomes of Dendrobium williamsonii and Dendrobium cariniferum were assembled and characterized using Illumina NovaSeq 6000. The genome sizes are 159 695 and 159 479 bp, including pairs of inverted repeats (27 055 and 27 024 bp) each separated by small single-copy regions (18 451 and 18 488 bp) and large single-copy regions (87 134 and 86 943 bp). The chloroplast genome overall GC content was 37.11% and 37.13%, respectively. Each chloroplast genome encoded the same number (147) of genes, including 88 protein-coding genes, 51 tRNA genes, and 8 rRNA genes. Comparative analysis of chloroplast genomes revealed the high degree of divergence included accD-psaL and ycf4 -cemA. The phylogenetic tree showed the two Dendrobium species formed only one small clade. A pair of primers that could effectively identify the two Dendrobium species were also screened. This study will provide theoretical basis for species identification, genetic breeding, and evolution of Dendrobium.

Roots are important for plant anchoring, water and nutrient absorption, and other physiological processes. Gravity is a primary determinant of the spatial distribution of plant roots in the soil. Therefore, in-depth understanding of the molecular mechanisms and biochemical networks of root responses to gravity has both theoretical and practical significance in guiding the genetic improvement of plants. Gravitropism, the process through which plants sense the direction of gravity and respond by making the roots grow downward and the stem grow upward, has been widely studied in roots. The perception of gravity and the gravitational growth of roots, key steps in root growth and development, are regulated by auxins and other factors. Here, we review the latest progress in the regulation of root gravitropism by hormone signals and environmental factors from a molecular perspective, and look forward to the direction of future research on root gravitropism.

Circular RNAs (circRNAs) are relatively new members of the RNA world and can contribute to crucial biological functions. CircRNAs have tissue-specific expression profiles depending on cell type and developmental stage. In Sistan region cultivated grapes are seedless but have small berries. The compact clusters are another notable characteristic of these grape cultivars, which negatively impacts their marketability. In this study, we aimed to identify the circRNAs that are active in cluster formation and investigated the effects of gibberellin treatment on their expression. Eight detection tools were used to predict the expressed circRNAs. Reliable circRNAs were used to identify potential functions of differentially expressed circRNAs by gene ontology (GO) analysis and prediction of target microRNAs (miRNAs). Of the 28 157 circRNAs detected, 3 715 were reliable. 900 differently expressed circRNAs were identified in the three developmental stages of the cluster under gibberellin treatment. Among the 503 target miRNAs found, 12 miRNAs were selected based on the number and expression of their circRNA sponges. Of the 29 circRNAs in the circRNAs-miRNAs-mRNAs interaction network, 12 circRNAs are highly conserved. Our results suggest that circRNAs in grape may play a key role in developmental and environmental adaptation in perennial plants.

The cuticle is the first physical barrier between the plant and the outer environment. The cuticle is no longer viewed as a rigid "inert sealer". Components of the cuticle were found to be responsive in their function and chemical composition to environmental signals. Cuticle creation is energy-consuming and complicated. Thus, cuticle composition and renewal dynamics are precisely regulated. Activated plant immunity is also energy "expensive". We briefly summarised our knowledge of the involvement of cuticle in plant-microbe interactions. Changes in cuticle amount and composition affect plant resistance to pathogens and treatment with cutin monomers triggers plant immunity. However, our knowledge about the effects of activated plant immunity on cuticle is scarce. We hypothesise that activated immunity influences cuticle dynamics. Our in-silico gene expression analysis revealed that cuticle biosynthetic genes are modulated under conditions simulating activated immunity. The analysis indicates that the cuticle is not just a rigid component of a plant reaction to the pathogen attack. Strengthening of the cuticle could prevent pathogen penetration. However, inhibition of cuticle production could save the energy needed for plant immunity. We propose questions which should be addressed in future research. Answering them would lead to a better understanding of plant defence against pathogens.

Bacterial diseases of vegetable crops cause significant losses of yield and substantially decrease food quality. For sustainable development of agriculture, it is highly important to use the most effective strategies for the protection of vegetable crops from bacterial diseases which allows the creation of resistant cultivars and their introduction in regions with an increased risk of damage by phytopathogenic bacteria. This paper reviews the most widespread bacterial diseases of tomatoes, the mechanisms of interaction of plants with phytopathogenic bacteria, and the advantages of the biotechnological strategies over traditional and marker-associated breeding for creation of the resistant tomato cultivars. The current research progress on the use of biotechnological approaches such as cell selection, genetic engineering, genome editing, and gene silencing is summarized, with a special emphasis on the advantages and limitations of these methods.

To obtain immediate homozygosity by androgenesis, the doubled haploid method is often used. As a result, a mapping population was created utilizing rice (Oryza sativa L.) cvs. Mahulata and IR 20 as parents in order to find QTLs/genes for drought tolerance at the vegetative stage. The effectiveness of the doubled haploids (DHs) approach, on the other hand, is largely dependent on the ability to distinguish haploids from diploids among the green regenerants. Although flow cytometry and cytological screening for pollen sterility can be used to identify haploids, these methods are expensive, time-consuming, and need a sophisticated laboratory with highly trained workers. Plant height and other spikelet features have also been used to differentiate haploids from doubled haploids. However, no systematic analysis of several morphological features for distinguishing haploids in doubled haploids has been published to date. As a result, a cost-effective approach for distinguishing haploids from true DHs obtained from anther culture is required. The goal of this work was to identify haploids using morphological features and simple microscopic examinations without the use of chemicals or complex laboratory facilities. The cross between the IR20 and Mahulata yielded a total of 198 anther culture (AC) derived plants. A group of 41 plantlets was chosen as putative haploids based on their shorter height and Cq values using qPCR-based genotyping and finally validated that, in addition to plant height, other morphological traits such as total number of leaves/plant, total number of tillers/plant, and floral characters can be used to successfully identify haploids. We report a variety of morphological signs as indicators of haploid plants, including smaller plants, higher tiller density, narrower and shorter leaf length, and partial exertion of panicle from the flag leaf sheath. Other morphological markers for identifying haploids from DHs include smaller florets and anthers, and small desiccated microspores.

The seasonal patterns of changes in the content of lipophilic antioxidants β-carotene (β-Car), zeaxanthin (Zx), α-tocopherol (α-Toc), plastoquinone (PQ)/plastoquinol (PQH2) were studied in the assimilating shoots of evergreen shrub Ephedra monosperma J.G. Gmel ex C.A. Mey under natural conditions of Central Yakutia. The shortening of the photoperiod and the seasonal decrease in temperature induced a 1.4-fold increase in α-Toc content. The fall in the average daily temperature from 0.1 to -8.1°C in October led to a decrease in the content of β-Car as a result of the accumulation of rhodoxanthin (Rhd). In this period a sharp increase in the content of Zx retained overnight was also detected. In winter, elevated content of Zx and α-Toc persisted. During September, the content of PQH2 increased by 2.5 times and PQ by 1.4 times (compared to July). The beginning of exposure to freezing average daily temperatures from -3 to -5°C led to the depletion of the total PQ pool by 18%. However, the content of PQtot in the winter months was 1.5 times higher than at the end of July. The results revealed different timing and temperature ranges of variation for individual antioxidants during the development of frost resistance in ephedra.

Bacterial leaf blight (BLB) is a common disease that affects rice development and yield. The effects of major nutrients, especially nitrogen, on rice BLB susceptibility have been considered when devising rational fertilization strategies. However, the defense mechanism of rice against BLB under phosphate (Pi)-deficient conditions remains uncertain. Jasmonic acid (JA) is a phytohormone produced by rice plants to respond to abiotic and biotic stresses. Here, the involvement of the JA pathway in rice response to Xanthomonas oryzae pv. oryzae (Xoo) under low Pi was investigated in two contrasting rice cultivars G299 and G22. Expressions of JA-related genes under low Pi and Pi-related genes under JA treatment were assessed. The resistant capacity of G299 and G22 against Xoo infection was also investigated. In the JA-sensitive and Pi-sensitive cv. G299, JA-related genes were highly expressed under low Pi, and low Pi-responsive genes were strongly upregulated under JA treatment. Neither JA nor Pi pathways were activated in the JA-tolerant and low Pi-tolerant cv. G22. Low Pi strongly enhanced rice resistance to Xoo in cv. G299. Our study demonstrated that Pi deficiency confers rice resistance to Xoo. The JA pathway modulates the response to low Pi, depending on the cultivar. Pi-response genes are involved in Pi stress and may participate in the regulation of overall plant growth under various abiotic stresses. These findings provide new insights into the interaction between phosphate deficiency and the JA pathway and the subsequent effect on plant disease resistance.

It is common knowledge that R2R3-MYB transcription factors play significant roles in plant biological and physiological processes, especially in the phenylpropanoid metabolism pathway. The cultivated strawberry (Fragaria × ananassa Duch.) is an octoploid (2n = 8x = 56) species from the Rosaceae family and it is also an important fruit crop species. However, the function of R2R3-MYB genes in strawberry remains largely unknown. Here, based on the genome of the cultivated strawberry cv. Reikou, 66 FanMYB genes were found and systematically analyzed. RNA-seq analysis revealed that some FanMYBs exhibited tissue-specific expressions and were methyl jasmonate (MeJA)-responsive. Phylogenetic relationships and protein-protein interaction analysis suggested that 13 FanMYBs were likely associated with phenylpropanoid metabolism. Out of these genes, FanMYB22, FanMYB36, FanMYB47, FanMYB49, and FanMYB63 were post-transcriptionally regulated by miR858 according to the degradome data analysis, suggesting the conservation and complex regulation network in F. × ananassa. Current findings provide a useful resource for future research on the function of FanMYBs and the regulatory mechanism of the phenylpropanoid pathway in strawberry.

Lycium barbarum Thunb. and Lycium ruthenicum Murray (wolfberries) have been utilized as traditional medicinal and nutritional plants in China for centuries. Much research has been focused on their high quality, yet the molecular mechanisms underlying morphological differences remain unclear. In this study, a comparative analysis of morphological and cytological characteristics indicated that significant differences existed. Meanwhile, transcriptomic analyses of the flower and fruit were performed at different developmental stages, and a total of 54 795 differentially expressed genes (DEGs) were screened. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses showed that these DEGs were significantly enriched in substance metabolism, catalytic activity, single organism process, starch and sucrose metabolism, carotenoid biosynthesis, amino sugar and nucleotide sugar metabolism, phenylpropanoid biosynthesis, and other pathways. Based on these significantly enriched pathways, the ratio between nonsynonymous and synonymous substitution rates (Ka/Ks), and numerous studies related to flower and fruit development, we preliminarily screened eight transcription factor families related to flower and fruit development and counted the number of potential transcription factor genes. These candidate genes could provide a basis for future functional verification, helping to further research on the molecular mechanism of morphological differences in the two Lycium species.

In order to explore the effect of exogenous 24-epibrassinolide (EBR, 0.1 µM) application on photosynthetic parameters in response to different light intensities and CO2 concentrations in maize seedlings under NaCl stress (180 mM), this study investigated the light response curve, CO2 response curve, and diurnal variation of photosynthesis of maize seedlings under NaCl stress. Maize cv. Jinlai 318 was used as the material, and the leaves were sprayed with 0.1 µM EBR. Net photosynthetic rate (PN), stomatal conductance (gs), intercellular CO2 concentration (Ci), and transpiration rate (E) were determined. The results showed that the light response curve, CO2 response curve, and diurnal variation trend under the four treatments (180 mM NaCl, 0.1 µM EBR, 180 mM NaCl with 0.1 µM EBR, pure water) were similar. The light saturation point of the leaves under NaCl stress was the lowest (about 1 031 mol m-2 s-1), and that in the control group (without stress) was the highest (about 1 344 mol m-2 s-1). When the light saturation point was reached (1 030 -1 350 mol m-2 s-1), the maximum PN under NaCl stress was the lowest (about 15.15 μmol m-2 s-1), while that under EBR treatment, it was the highest (about 19.86 μmol m-2 s-1). NaCl stress significantly reduced chlorophyll a, chlorophyll b, and carotenoid content and chlorophyll a/b ratio, while chlorophyll content significantly increased after EBR treatment. These results showed that exogenous EBR could effectively alleviate the damage to maize seedlings under NaCl stress, delay the light saturation phenomenon, and improve the photosynthetic capacity of maize.

Low temperature is one of the most severe abiotic stress factors that limit chrysanthemum growth and development. Natural temperature changes are more complex, and cold stress from a laboratory incubator cannot accurately represent the natural temperature stress. Here, nine separate high-throughput mRNA sequencing technology (RNA-Seq) libraries were generated from the RNA sample of roots from different temperatures, including chilling (Ch), freezing (Fr), and control (CK). The 7 069 and 3 952 differentially transcribed genes were identified as CK vs. Ch and CK vs. Fr, respectively. The Kyoto encyclopedia of genes and genomes pathway (KEGG) enrichment analysis showed that significantly different flavonoid biosynthesis and linolenic acid pathways commonly appeared in CK vs. Ch and CK vs. Fr. Arginine and proline metabolism, lipid metabolism, fatty acid degradation, and fructose and mannose metabolism pathways were found in CK vs. Ch, and only in the CK vs. Fr enrichment metabolic pathway included steroid biosynthesis and monoterpenoid biosynthesis. The transcription of genes on differential metabolic pathways and MYBs were successfully validated using quantitative real-time PCR. At the same time, the antioxidant activity, malondialdehyde, and proline content were analyzed under low temperature. These datasets may aid in understanding and carrying out future studies on the molecular basis of cold stress and contribute to chrysanthemum breeding.

Solanum nigrum L. is an annual undomesticated berry plant of Solanaceae. The fruits of S. nigrum are tiny, but there are about 25 seeds in a single fruit. The total number of seeds produced in one plant can reach more than 3 000. The height is about 30 - 40 cm, and the whole growth cycle is two months when S. nigrum was cultivated in the light incubator of the laboratory. The Agrobacterium tumefaciens-mediated transformation has been established in S. nigrum. So S. nigrum has the characteristics of model plants. AcMYB110, an R2R3-MYB transcription factor from kiwi (Actinidia spp.), was transformed into S. nigrum mediated by A. tumefaciens. The results indicated that the petals of 35S:AcMYB110 S. nigrum plants are pink compared with white petals in wild-type plants, and content of anthocyanins was significantly increased in the pericarp from young fruit to its maturity, especially in the central part of the fruit flesh. The results showed that the ectopic expression of AcMYB110 in S. nigrum is consistent with the expression of AcMYB110 in kiwi. This suggests that AcMYB110 plays a conserved role in regulating anthocyanins synthesis in fruits and can be potentially applied for improvement of the anthocyanins content in horticulture fruits breeding.

Soil salinity leads to a reduction in plant growth, germination, relative water content, and production of wheat plants worldwide. Chitosan showed a positive effect on plant growth and development and improved plant stress tolerance. The current study aimed to examine the effect of different chitosan concentrations on the gamma-aminobutyric acid (GABA) shunt pathway in germinating seeds of wheat (Triticum durum L.) under salt stress (25 - 200 mM NaCl). We determined the seed germination pattern, seed moisture content, GABA shunt metabolites (GABA, glutamate, and alanine), oxidative damage in terms of malondialdehyde (MDA) accumulation, and the glutamate decarboxylase (GAD) mRNA transcription. Pre-treatment of wheat seeds with chitosan improved germination by enhancing germination percentage, seedling length, and seedling fresh and dry masses under salt stress. Data showed an increase in GABA shunt and their metabolites (alanine and glutamate), MDA content, and GAD mRNA transcription, and a decrease in germination percentage, seedling length, seedling fresh and dry masses for both untreated and chitosan-treated seeds under salt stress. Our results suggest that the elevation of GABA in chitosan-treated seeds was able to maintain metabolic stability under salt stress. The MDA content increased in chitosan-treated seeds as NaCl concentration increased, however, the increase was slightly lower than the MDA content in untreated seeds which confirmed that chitosan activates GAD mRNA expression that leads to activate GABA shunt to involve in the reduction of membrane damage and activation of reactive oxygen species scavenging systems under salt stress. Consequently, this study demonstrated that chitosan significantly enhanced the accumulation of GABA and amino acids metabolism to maintain the C:N balance and improved salt tolerance in wheat seeds during seed germination.

Transcriptome is a collection of mRNA transcripts in a specific physiological state which has become one of the hotspots in biological research to evaluate the genes and networks in different kinds of plants. Transcriptome sequencing technology dates back to 1964 and has nearly 60 years of history. At present, the research mainly focuses on cultivating, breeding, molecular markers, and gene mining. With the increase in oil price, woody oil production can alleviate oil demand, but there are few review articles and molecular biology studies on the transcriptome of woody oil plants. In the past few decades, woody oil plants have made great progress in the development of transcriptome sequencing and bioinformatics. In this review, we reviewed the development history of sequencing technology and the research on the transcriptome of woody oil plants, mainly introducing the germplasm resources, molecular markers, and the application of important functional genes in woody oil plants. This paper not only provides ideas for mining functional genes of oil plants but also provides a reference for molecular breeding research of woody oil plants in the future.

The present work aimed to evaluate the effect of heat stress on common bean (Phaseolus vulgaris L.) genotypes during the reproductive phase as a function of the inoculation of plants with Bacillus subtilis. The treatments were established by inoculating two strains of B. subtilis (AP-3 and AP-12) and a control. The plants were subjected to heat stress when they reached the reproductive stage, with an increase in temperature to 28/33°C. The duration of the stress period was ten days. Flowering, biochemical, and gene expression evaluations were performed. There was the interaction of B. subtilis AP-3 with the bean cultivar IAC-Imperador, reducing flower abortion, promoting the formation of new flower buds, and increasing the content of proline and guaiacol peroxidase activity in plant tissues. However, there was a reduction of transcription of genes encoding the 1-carboxylic acid-1aminocyclopropane oxidase and ethylene response factors and an increase of the Δ1-pyrroline-5-carboxylate synthetase1 gene. These results suggest that B. subtilis may modulate some metabolic pathways in response to high-temperature stress during the reproductive phase of the common bean. This also confirms that Bacillus strains represent a useful option to moderate abiotic stresses.

The "Centre for Experimental Plant Biology", a joint project of the Institute of Experimental Botany of the Czech Academy of Sciences and CEITEC (represented by Mendel and Masaryk Universities), focused on elucidating the mechanisms of plant responses to abiotic and biotic stresses and their combinations at the cellular level, in intact plants during vegetative and reproductive stages, and fruit development. The consortium demonstrated the importance of shared research facilities, complementary approaches, and knowledge exchange, addressing demanding questions in plant biology. The consortium made breakthrough in plant-pathogen interactions, including identification of exocyst-syntaxin cooperation in non-host resistance. The results confirmed the fundamental role of phytohormones in stress responses, including negative correlation of leaf bioactive gibberellins with drought stress, and the role of cytokinins in ROS homeostasis, sulphur metabolism, and heat stress responses, including volatile emission. Molecular analyses revealed expansin-mediated cell wall remodelling, brassinosteroid-mediated regulation of root growth through PIN2, the role of ALBA and LARP6C proteins in pollen development under abiotic stress, and heat stress impact on fertilization rate, embryo and seed development. Gene Set Enrichment and RNA-Seq analyses allowed to identify crucial genes involved in the apple scab resistance network. The main results obtained during the five-year project are summarised here.

Involving the natural host-resistance mechanisms to pathogens are essential and one of the most promising approaches in development of first-line defenses against viral plant diseases. Polysaccharides isolated from natural sources are considered the most active resistance inducers. The biological activity of polysaccharides depends on the nature and chemical structure of the constituent components of complex preparations. In this view, the objective of our study was to evaluate the biological activity of complex preparations composed of glycans, rhamnolipids, and thiosulfonates as inducers of natural plant resistance and inhibitors of tobacco mosaic virus (TMV). Complex preparations were obtained using the following components: biogenic glycolipids - rhamnolipids of the Pseudomonas sp. strain PS-17, glycans - Ganoderma adspersum glucan and Candida maltosa mannan, as well as synthetic biocides - thiosulfonates (methylthiosulfanilate). The biological activity of the preparations was investigated in the host-virus model system Nicotiana tabacum L. and TMV. It was shown that preparations at concentrations of 10 and 100 μg mL-1 were active plant resistance inducers in N. tabacum cv. Immune 580, hypersensitive to TMV. At the same concentrations, complex preparations also reduced infectivity of TMV on Datura metel L. acting as viral infection inhibitors. The inducing activity of the complex preparations is sensitive to well-known transcription inhibitor actinomycin D (10 μg mL-1). This fact may indicate the important role of RNA synthesis in the activation of plant virus resistance by the studied preparations.

Seedling greening upon irradiance is essential for the survival of plant after germination. Here, we studied the role of nitric oxide (NO) in regulating the accumulation of chlorophyll during greening of Arabidopsis seedlings, and we also investigated the changes of ATP in the chloroplast and cytoplasm during greening by using a fluorescent protein sensor (Ateam 1.03-nD/nA) based on fluorescence resonance energy transfer (FRET) and the effects of NO on the changes of ATP content. The results showed that the content of NO, chlorophyll, and ATP in the chloroplast and cytoplasm increased with the increase of greening time. L-NAME, an inhibitor of NO, not only decreased the accumulation of chlorophyll content but also reduced the ATP content in the chloroplast and cytoplasm during the greening of Arabidopsis seedlings. Therefore, these experiments indicate that the accumulation of chlorophyll and changes of ATP during greening of etiolated Arabidopsis seedlings are mediated by nitric oxide.

Two ginseng species Panax vietnamensis and Panax stipuleanatus are precious medicinal plants restricted in several Vietnam provinces. They are very limited and endangered due to degraded habitats and over-harvesting. To preserve these two species, we used eight nuclear microsatellite markers to investigate genetic variability from the nine populations with 246 individuals for these two ginseng species. Our findings showed a moderate genetic heterozygosity in two species, P. vietnamensis (HE = 0.386) and P. stipuleanatus (HE = 0.342). Deficiency of heterozygosity was observed in all the studied populations of P. vietnamensis and three populations of P. stipuleanatus. Some populations had high allelic richness for both species. Private alleles were determined in all the studied populations of P. vietnamensis and two P. stipuleanatus populations. Genetic differentiation was low in two ginseng species. However, habitat loss, over-utilization and over-harvesting can be the main causes of reduced genetic heterozygosity. Neighbor-joining tree and discriminant analysis of principal components detected three major genetic groups. Finally, based on our findings, we propose in situ conservation of populations with high expected heterozygosity, allelic richness, and private alleles. Seed collection should be performed for ex-situ conservation as genetic pools in the future.

The analysis of single nucleotide polymorphisms of 107 maize inbreds was performed on 384 special single nucleotide polymorphism (SNP) markers to receive their unique certificates and determine their degrees of affinity and heterotic potential. All inbreds were selected in the steppe zone of Ukraine; among them, 39 inbreds belonged to the Iodent and 28 inbreds to the BSSS germplasms. 40 inbreds of the Iodent/BSSS breeding group developed after hybridization of Iodent and BSSS, were also analysed by the same SNP markers. The average homozygosity of lines amounted to 98.05%, and the genetic diversity was 0.1746. According to pairwise SNP distances, lines of the Iodent and BSSS pedigrees formed two separate clusters, while the Iodent/BSSS lines were distributed among them. The allelic patterns of SNP markers specific for Iodent and BSSS inbred lines in comparison with each other and with the original inbreds P165, B14, B37, and B73 were formulated and discussed. Inbreds within the Iodent germplasm were on average much more closely related (GD = 0.2494) than those within the BSSS germplasm (GD = 0.3900) and the Iodent/BSSS breeding group (GD = 0.3967). The potential of the heterotic model Iodent×BSSS was assessed as high (mean GD = 0.4509). Based on SNP distances, inbreds have been recommended for the development of single cross heterotic hybrids, sister hybrids, and initial populations for subsequent breeding cycles.

Radix astragali, from the roots of Astragalus L. species, is regarded as an important traditional medicinal plant and has been widely used as a Qi-Invigorating medicine for more than 2 000 years. Considering the different metabolites or functional compounds of Radix astragali from distinct species, the underlying genetic information among the two species is important. Here, we compared the two different root transcriptomes and expression patterns of genes involved in key medicinal secondary metabolites of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao and Astragalus membranaceus (Fisch.) Bge. A total of 98 017 578 and 102 635 956 reads, including 98 294 560 and 92 494 416 high-quality reads, were obtained for A. mongholicus and A. membranaceus, respectively. In general, 73 785 (39.47%) and 60 739 (34.93%) unigenes for A. mongholicus and A. membranaceus were differentially expressed, indicating that the two species had many homologous genes. In comparison, the carbon metabolism category contained the most abundant unigenes in A. mongholicus, and it contained many more genes than those found in A. membranaceus based on the KEGG results. Genes that may participate in the biosynthesis of flavonoids, diterpenoids, triterpenoids, steroids, isoquinoline alkaloids, and carotenoids, such as CHS, F3H, GA3, and CYPs, were identified based on annotations. A total of 5 227 and 5 101 transcription factors (TFs) were identified in A. mongholicus and A. membranaceus, respectively. Three TF categories were found and showed twice as many numbers for A. mongholicus than A. membranaceus, i.e., SOH1 (4:2), LIM (18:5), and GRF (19:5), while MED7 had more unigenes in A. membranaceus (6:12). These results indicated that the different pathways may be involved in the synthesis of active ingredients in the two germplasm resources, and the data obtained will provide valuable information for further utilization and investigation of these two species.

The impact of climate change on the physiological processes of Norway spruce in Central Europe is a significant concern. The increased temperature and evaporative demand associated with climate change may negatively affect its photosynthesis and carbon-water balance. This study tests the combined effect of branch position, temperature (T) and water vapour pressure deficit (VPD) on net photosynthetic rate (PN), water vapour stomatal conductance (gs), and intrinsic water-use efficiency (WUEi) of Norway spruce. More than 11 000 gas-exchange measurements during the summer of 2018 revealed that branch position significantly affects gas exchange and WUEi of juvenile Norway spruce trees. Northern branches showed on average 21% increased PN, 35% higher gs, and 8% lower WUEi compared to the southern branches (across T and VPD conditions). The PN and gs differences between the branches were temperature- and VPD-dependent. We observed the negative impact of raising temperature on gas exchange and WUEi for both treatments, with a 40°C threshold causing a rapid decline in WUEi. Variability of the southern branches' WUEi at 42°C was abruptly increased due to the decoupling of PN and gs (low PN, high gs). Surprisingly, raising VPD showed no significant impact on WUEi of Norway spruce. The results of this study provide necessary information for upscaling and process-based modelling of whole-crown gas exchange. Moreover, experimental studies of gas exchange should take into consideration the branch position effect to prevent possible bias errors.

Mesembryanthemum crystallinum is a model halophyte that switches from C3 photosynthesis to Crassulacean acid metabolism (CAM) upon extreme abiotic stresses. This study aimed to investigate alkalinity-induced root transcriptome profiling in M. crystallinum. M. crystallinum seedlings were treated with 50 mM sodium bicarbonate (NaHCO3; pH 7.5) and 90 mM NaHCO3 (pH 9.5) for 7 d, respectively. Alkalinity-induced differentially expressed genes (DEGs) were identified and annotated. Functional enrichment analysis was performed for DEGs. The expression of genes related to response to stress and CAM were analyzed and compared. Comparing with control, 50 and 90 mM NaHCO3 treatments induced 4 027 and 25 403 DEGs in M. crystallinum roots, respectively. Among these DEGs, 832 and 131 DEGs were consistently upregulated and downregulated by both stresses, respectively. These genes were associated with multiple biological processes related to response to abiotic stresses. Alkaline stress upregulated genes encoding heat shock proteins and ethylene-related genes, but downregulated genes encoding glutathione S-transferases. Also, genes that encode phosphoenolpyruvate carboxylases, phosphoenolpyruvate carboxylase kinase 1, and malate dehydrogenases related to malate accumulation were upregulated by alkalinity. This study indicated that alkaline stress affected the genes related to stress responses, metabolism, and malate accumulation in the roots of M. crystallinum.

Artemisia japonica Thunb is an important perennial herb containing abundant chemical compounds utilized in conventional medicine for the treatment of malaria, hepatitis, hypertension, and inflammation. The protoplasts-based transient transformation system is a versatile and convenient tool for functional gene analysis in several Artemisia species. However, effective protoplast preparation and transformation systems are still lacking for A. japonica. We developed an efficient protoplast-based transformation system by optimizing conditions of protoplasts isolation and polyethylene glycol (PEG)-mediated transformation in A. japonica. The optimum conditions for the protoplast preparation were: the enzyme solution containing 1.75% (m/v) cellulase R10, 0.5% (m/v) macerozyme R-10, and 0.4 M D-mannitol with proper leaves treatment and pre-plasmolysis treatment. The maximum protoplast yield was 1.93 × 106 protoplasts g-1(FM) and the viability of protoplasts was approximately 87.5% under optimized conditions using an orthogonal experiment. Furthermore, the transient protoplast transformation efficiency was 47.86% in A. japonica protoplast under the conditions of 40% (m/v) PEG 4000 for 20 min. The establishment of A. japonica protoplasts isolation and transient transformation system can accelerate the gene function studies of A. japonica and provide a fast and simple gene expression platform for molecular, biochemical, and functional gene characterization for other Artemisia species.

Leaves of Lotus japonicus infected by powdery mildew accumulate isoflavonoids, especially vestitol and sativan as protective compounds, whereas their flavonol-glycosides or phenylpropanoic acids content were rather decreased. For a better understanding of the induction of phytoalexin production in L. japonicus, the influence of important signalling molecules, namely methyl jasmonate and salicylic acid, was tested by leaf application, up to 15 d. No effects after spraying the leaves with 0.5 mM salicylic acid were observed regarding the plant isoflavonoid content, whereas methyl jasmonate showed moderate effect on vestitol accumulation. Chitosan application led to a strong increase in vestitol content, sativan and vestitol derivative also increased. In a similar way to the effect of powdery mildew infection, the content of ferulic acid and kaempferol glycosides decreased, except for one compound, identified as kaempferol-6-deoxyhexose, that is the result of acetylation of kaempferol glycosides. The application of chitosan also led to an approximately 2.5- to 3.5-fold increase in hydrogen peroxide content, indicating the involvement of H2O2 in the chitosan signalling pathway. The activity of key enzyme of the phenolic biosynthesis, phenylalanine amonia lyase (PAL), was stimulated as well as the expression of 3 PAL-isogenes (LjPAL4, LjPAL6, and LjPAL9), whereas LjPAL8 decreased. Moreover, the expression of two key enzymes of vestitol and sativan biosythesis: pterocarpan reductase and isoflavone synthase were also strongly induced. The data suggest that chitosan acts as an elicitor of the fungal attack in Lotus japonicus that do not lead to a general stimulation of the metabolism of phenols, but rather to a specific induction of isoflavonoid-phytoalexine production, especially for production of vestitol.

Tomato spotted wilt virus (TSWV) has significant economic impact on horticulture worldwide. One of the five proteins encoded by TSWV genome is the multifunctional NSs protein, which is a viral suppressor of RNA silencing (VSR) besides functioning as the effector of Tsw resistance gene in resistant pepper cultivars. In this study we demonstrate the in vivo self-interaction of NSs protein using bimolecular fluorescence complementation and yeast two-hybrid assays, and propose that a highly charged alpha helix located at the second half of the protein is required for self-interaction. Furthermore, we confirmed that self-interaction is not required for its effector function on pepper. Moreover, self-interaction is dispensable for gene silencing suppressor activity, although it enhances the suppression efficiency.

The artichoke (Cynara cardunculus subsp. scolymus) is an intriguing source of indigestible sugar polymers such as inulin-type fructans. Artichoke represents an important component of a traditional Mediterranean diet and its edible parts are a good source of many high added value compounds such as inulin, a polymer showing relevant prebiotic properties. Compared to the cultivated varieties, the wild cardoon (C. cardunculus var. sylvestris) growing naturally under harsh conditions and well-adapted to many marginal areas, could have a good potential for use in sustainable production in stressed lands. Here, we evaluated by enzymatic assay, the amount of inulin-type fructans both in artichoke and wild cardoon in the two different organs, heads and rhizomes. The expression pattern of the genes encoding the two key enzymes sucrose:sucrose 1-fructosyltransferase and fructan 1-fructosyltransferase, involved in fructan biosynthesis, have been also evaluated. Our results showed that the amount of inulin-type fructans was higher in the wild cardoon than in the artichoke heads, together with a higher expression of the two key genes involved in the fructan biosynthetic pathway. A conspicuous content of inulin-type fructans was found also in the rhizome, supporting the significant role of these compounds in the storage and in protection from cold and/or winter stresses.

Populus euphratica belongs to Salicaceae family and grows in extreme desert environments. At present, the identification of the AP2/ERF gene family of transcription factors in Salicaceae is rare, and the role of the AP2/ERF gene family in P. euphratica under salt stress and exogenous hormones has not been reported. In this study, 197, 210, 231, 192, and 147 AP2/ERF genes were identified in P. euphratica, Populus trichocarpa, Populus deltoides, Salix sinopurpurea, and Arabidopsis thaliana, respectively. The 197 AP2/ERF gene family members of P. euphratica were divided into five subfamilies, namely, AP2 (35), RAV (5), ERF (96), DREB (65), and Soloist (1), by sequence alignment and phylogenetic analysis. In addition, these genes were scattered across 19 chromosomes. The detection of 10 motifs in the P. euphratica AP2/ERF gene family revealed that motif-8 and motif-9 only appeared in the ERF subfamily and DREB subfamily, respectively. Transcriptome data showed that PeAP2/ERF genes had different expression patterns under salt stress, abscisic acid (ABA) and gibberellic acid (GA3) treatments, suggesting that the genes PeERF002, PeERF037, PeERF082, PeERF090, and PeAP2-14 may play important roles under salt stress and exogenous hormone treatments. This study provides a reference for the functional study of the PeAP2/ERF gene, and it also lays a foundation for the breeding strategy to improve the salt tolerance of P. euphratica.

Tetracentron sinense Oliv, the only tall deciduous tree in the family Tetracentraceae, is listed as a national second-grade key protected plant in China. To reveal the effect of associated species, irradiance, and altitudes on photosynthetic capacity of T. sinense, photosynthetic physiological characteristics of T. sinense and its associated species Acer pictum and Pterocarya stenoptera were measured by a Li-6400 portable photosynthetic meter. The light saturation point (LSP), the maximum net photosynthetic rate of the PN-PAR (PNmax), carboxylation efficiency (CE), the maximum net photosynthetic rate of the PN-CO2 (P*Nmax), carbon dioxide compensation point (CCP) and light respiration rate (Rp) of T. sinense in forest gap (FG) were higher than those in forest edge (FE) and understory (US). In FE, the net photosynthetic rate (PN), light compensation point (LCP), LSP, P*Nmax of T. sinense were lower than those of Pterocarya stenoptera, while the LSP, PNmax, and saturation point of carbon dioxide (Ciast) of T. sinense in US were lower than those of Acer pictum and Pterocarya stenoptera. The specific leaf area (SLA) of T. sinense decreased with reduction in the irradiance. With increasing altitude, the PNmax, LSP, and SLA of young individuals of T. sinense (YT) increased; the LCP of YT or the LSP of mature individuals of T. sinense (MT) increased first and then decreased. The results showed that 1) the photosynthetic capacity and adaptability of T. sinense were better in FG than that in FE and US; 2) the photosynthetic capacity of T. sinense in FE and US was weaker than that of its associated species, and its ecological range of light adaptation was also narrower than that of its associated species, placing T. sinense at a competitive disadvantage, which may be one of the important reasons for its poor regeneration; and 3) the environmental conditions at higher altitude can contribute to the growth and survival of T. sinense. Therefore, active artificial intervention should be undertaken to expand area of forest gap for T. sinense and transplant its seedlings to higher altitude to promote growth and population regeneration of T. sinense.

Ascorbic acid (AsA) and glutathione (GSH) contribute to defense responses under abiotic stresses. The present study explored the ascorbate-glutathione cycle and ascorbate regeneration under high concentration (30 mM) of cadmium in the tea plant (Camellia sinensis L.). The tea leaves showed speckles and necrosis from the third day of Cd treatment. The content of superoxide anion (O2.-) and hydrogen peroxide (H2O2) in the leaves were significantly higher until the seventh day after Cd treatment. The content of O2.- and H2O2 were the highest on the fifth day (212.7 and 153.6 % of the control, respectively). The AsA content increased (86.9 %) on the first day after Cd treatment and decreased significantly in the subsequent days, while GSH showed a reverse trend. The enzymatic activity assays showed that dehydroascorbate reductase (DHAR) and glutathione reductase (GR) involved in AsA regeneration were downregulated considerably after Cd foliar application. In contrast, the activities of ascorbate peroxidase (APX) and monodehydroascorbate reductase (MDHAR) increased on the first day and then declined. Reverse-transcription quantitative PCR showed upregulation of glutathione synthetase (CsGSHS), γ-glutamylcysteine synthetase (Csγ-ECS), and CsMDHAR of the AsA regeneration pathway and downregulation of CsDHAR and CsGR. The expressions of GDP-L-galactose phosphorylase (CsGGP), L-galactose-1-phosphate phosphatase (CsGPP), and L-galactono- 1,4-lactone dehydrogenase (CsGaILDH) of the L-galactose pathway were also downregulated. The results indicated that AsA, which can respond to Cd stress of plants by increasing antioxidant ability, was consumed to scavenge ROS; moreover, Cd stress inhibited AsA synthesis and regeneration, which made that tea plants suffering severe damage.

Garlic mustard (Alliaria petiolata) is an herbaceous biennial plant native to Europe. In Ukraine, in addition to becoming a serious invader, garlic mustard can serve as a host to several viruses, which may affect agricultural crops. In view of this, the purpose of the study was to identify the virome of garlic mustard growing in Ukraine. Plant samples collected in Kyiv regions were tested for the presence of cucumber mosaic virus (CMV), turnip mosaic virus (TuMV), turnip yellow mosaic virus (TYMV), watermelon mosaic virus II (WMV), and turnip crinkle virus (TCV) by serological and/or molecular methods. According to the results found in the present study, symptomatic A. petiolata obtained in 2021 were infected with CMV (60%), TuMV (20%), or co-infected with CMV + TuMV (20%). TYMV, WMV II, and TCV were not detected in any of the collected samples. The cDNA fragments encoded the coat protein (CP) gene of CMV and TuMV were sequenced and named as CMV-Ap and TuMV-Ap, respectively. In phylogenetic analysis, the CMV-Ap closely resembled the German isolate MW582807 (Sarracenia sp.), with 99.8% nucleotide identity and belongs to subgroup II of CMV. In the phylogenetic tree, TuMV-Ap clustered with isolates AP017803, AP017764, AP017791, and JQ073722, and represented the highest identity (98.6%) to Iranian isolate IRNTRa9 (AP017803) from Rapistrum rugosum and Turkish isolate TUR49 (AP017872) from Raphanus raphanistrum. The sequences of CMV-Ap and TuMV-Ap were deposited in the GenBank under Accession Numbers MZ540213 and OM799323, respectively. The results obtained in the study indicate the important role of infected garlic mustard as alternative host and natural reservoir of CMV and TuMV from which these economically important viruses can spread to other wild and cultivated plants. This is the first molecular evidence of TuMV infection in A. petiolata from Ukraine.