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.

With the drastic changes in global climate and the increasing frequency of extreme weather events, abiotic stress poses a significant threat to future food crop production and is a major contributor to crop yield reduction (Ahmad et al., 2010). Wheat, one of the world's primary food crops, is susceptible to both abiotic and biotic stresses at all stages of its growth and development. Numerous studies have indicated that drought stress severely limits the growth and productivity of wheat (Xue et al., 2014; Faran et al., 2019). Therefore, understanding the effects of drought stress on wheat grain germination and developing strategies to mitigate the inhibition of germination caused by drought are crucial for enhancing wheat yield.

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.

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.

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.

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.

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.

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.

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.

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.

Long-term low temperatures restrict the regrowth of winter wheat (Triticum aestivum L.), thus decreasing agricultural output. Non-enzymatic expansins, which are related to plant growth, have been reported to respond to drought, salinity, and low-temperature stress. We obtained an expansin 3 gene, TaEXPA9. It is located in winter wheat cv. Dongnong with high cold hardiness. We analyzed the expression patterns of TaEXPA9-A/B/D in this cultivar and conducted a subcellular localization analysis of TaEXPA9-A/B/D in the onion epidermis. Transgenic Arabidopsis thaliana line with EXPA9-A/B/D overexpression was obtained to examine the effects of the orthologous genes of these expansins on plant growth and low-temperature stress resistance. The results showed that EXPA9-A/B/D expression significantly increased at 4 °C, it was higher in the roots than in shoots, and EXPA9-A/B/D was localized in the cell wall. The roots were well-developed in the transgenic A. thaliana, and the growth-related markers and setting rate were better than in the wild-type. Recovery was stronger in the transgenic plants after freezing stress. At low-temperature stress, the antioxidant enzyme activities and content of osmoregulatory substances in the TaEXPA9-A/B/D-overexpressing A. thaliana plants were significantly higher than in the wild-type plants, and the degree of membrane lipid peroxidation was lower. In summary, TaEXPA9 orthologous genes participate in the low-temperature stress response, and they might be of great importance in molecular breeding.

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 4^th 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.

Sugars are important molecules that function not only as primary metabolites, but also as nutrients and signal molecules in plants. The sugar transport protein genes family SWEET has been recently identified. The availability of the Dendrobium officinale and Phalaenopsis equestris genome sequences offered the opportunity to study the SWEET gene family in this two orchid species. We identified 22 and 16 putative SWEET genes, respectively, in the genomes of D. officinale and P. equestris using comprehensive bioinformatics analysis. Based on phylogenetic comparisons with SWEET proteins from Arabidopsis and rice, the DoSWEET and PeSWEET proteins could be divided into four clades; among these, clade II specifically lacked PeSWEETs and clade IV specifically lacked DoSWEETs, and there were orthologs present between D. officinale and P. equestris. Protein sequence alignments suggest that there is a predicted serine phosphorylation site in each of the highly conserved MtN3/saliva domain regions. Gene expression analysis in four tissues showed that three PeSWEET genes were most highly expressed in the flower, leaf, stem, and root, suggesting that these genes might play important roles in growth and development in P. equestris. Analysis of gene expression in different floral organs showed that five PeSWEET genes were highly expressed in the column (gynostemium), implying their possible involvement in reproductive development in this species. The expression patterns of seven PeSWEETs in response to different abiotic stresses showed that three genes were upregulated significantly in response to high temperature and two genes were differently expressed at low temperature. The results of this study lay the foundation for further functional analysis of SWEET genes in orchids.

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.

A plasmid and two isocaudamer systems, namely, NotI/Bsp120I and SpeI/XbaI/NheI, were used to construct a new type of multi-gene plant transformation vector system. This system included a transformation vector containing the restriction enzyme cutting sites Bsp120I and XbaI as well as a cloning vector containing the restriction enzyme cutting sites NotI, Bsp120I, SpeI, and NheI. The open reading frame of the new target genes was connected to the transformation vector. The original restriction enzyme cutting site disappeared after connecting to the isocaudamer. The plant transformation vector p096871, which contained Bacillus thuringiensis (Bt) genes Cry1Ac and Cry3A as well as p09X6, which contained mtlD, strD, betA, nhaA, and ostAB, were constructed using this vector system. Resistant plants were obtained after tobacco was transformed by two vectors via the Agrobacterium-mediated method. Detection by PCR revealed that all exogenous genes were inserted into the genome of tobacco. Real-time fluorescence quantification PCR, reverse transcription PCR, and ELISA detections were performed on five transgenic lines transformed by two Bt genes. Cry1Ac and Cry3A were inserted into the genome with a single copy to transcribe and express Bt toxins. The proposed vector system reduced the number of operational procedures and minimized the difficulty of the experiment.

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.

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.

Chinese cabbage (Brassica rapa L. ssp. pekinensis) is one of the most important economic crops. However, its yield and quality can be severely threatened by Turnip mosaic virus (TuMV). Emerging evidence indicates that epigenetic mechanisms, especially DNA methylation, play an important role in regulating gene expression. Therefore, identification of resistance genes modified by DNA methylation during the virus infection would provide a critical clue for improving disease resistance breeding programs. Here, we present detailed analysis for the correlation of DNA methylation and gene expression involved in several anti-pathogen pathways. We also found that different methylation patterns exist in different methylation sites (CG, CHG, and CHH, where H represents A, G, or T) and genomic regions. Furthermore, we identified disease-resistant genes related to the nucleotide binding site-leucine-rich repeats family, auxin, salicylic acid signaling transduction, cell wall biosynthesis, and protein degradation among the different methylated genes (DMGs) suggesting that these genes may be modified by DNA methylation and work together to activate an immune response. The identified DMGs are a valuable resource for discovering resistance genes. Our study not only provides valuable data for future biotechnology research and epigenetic studies, but also helps to explore how the epigenetic mechanisms modify antiviral pathways.

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.

Owing to cold resistance and a lack of heat resistance in spinach (Spinacea oleracea L.), heat is the primary constraint that limits its production in summer. This study examined the auxiliary effects of spinach rhizosphere microbes on improving the heat resistance of spinach. A strain isolated from the rhizosphere soil of heat-stressed spinach was identified as Bacillus subtilis and designated B. subtilis BE-L21. It produces indoleacetic acid, amylase, and protease and solubilizes phosphorus. Further research revealed that spinach seedlings inoculated with this strain of B. subtilis had increased content of soluble protein, soluble sugar, and proline that adjusted their osmotic potential. The reducing content of malondialdehyde showed alleviated irreversible damage of spinach plants under heat stress. Also the increased activities of antioxidant enzynes peroxidase, superoxide dismutase, and catalase enhanced the heat resistance of spinach. The results indicate that B. subtilis BE-L21 can contribute to tolerance of spinach seedlings to elevated temperatures by inducing physiological and biochemical changes in the plant.

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.

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.

Midvein is an important structure of the upright leaf of rice, and its normal development is essential to the formation of a common plant type of rice (Oryza sativa L.). To reveal the effect of midvein deficiency on photosynthesis-related characteristics, leaf microstructure, and vein characteristics, the photosynthetic features between the midvein-deficient mutant dl-14 and wild-type Huanghuazhan plants were analyzed. The results indicated that the midvein area of the dl-4 mutant lacked large intercellular space and instead it was filled with mesophyll cells. Moreover, the vein density of the dl-14 mutant was significantly higher than that in cv. Huanghuazhan. Chlorophyll (Chl) a, Chl b, and carotenoid content were markedly elevated in dl-14. In terms of photosynthetic characteristics, we observed that under high irradiance and high CO₂ concentration, the net photosynthetic rate of dl-14 plants was significantly higher than that of Huanghuazhan plants, but its water use efficiency was significantly lower. In addition, several major photosynthetic parameters, including characteristics of chlorophyll fluorescence (the efficiency of excitation capture of open PS II center, photochemical quenching, effective quantum yield of PS II photochemistry, and electron transfer rate) were significantly higher in dl-14 plants compared to Huanghuazhan plants, but the nonphotochemical quenching of dl-14 mutant was significantly lower than that of Huanghuazhan. These findings indicate that the dl-14 mutant has higher vein density, stronger photon conversion ability, and weaker radiation dissipation ability. This study can provide theoretical support for breeders to use the midvein-deficient mutant.

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.

Trehalose is a nonreducing disaccharide that is involved in the regulation of plant responses to a variety of environmental stresses. Trehalose 6-phosphate synthase (TPS) and trehalose 6-phosphate phosphatase (TPP) are two key enzymes in trehalose synthesis and they are widely distributed in higher plants. At present, TPS family genes have been systematically identified and analyzed in many plant species, but the TPP family genes have been rarely studied. In this study, ten TPS and six TPP genes in cannabis (Cannabis sativa L.) were identified at the genomic level. The phylogenetic tree of TPS and TPP family members in cannabis, Arabidopsis, and rice was constructed, and all the genes were divided into three subgroups: Class I, Class II, and Class III. The number of exons and motif types among Class I members was exactly the same, as were Class II members, but the gene structure and motif types of Class III members were slightly different. There were four pairs of CsTPSs and CsTPPs that had gene duplication, indicating that gene duplication events played an important role in the amplification of TPS and TPP families in cannabis. The results of expression analysis under abiotic stresses showed that 68.75 % of CsTPS and CsTPP genes were significantly induced by at least one abiotic stress. Among these genes, the expression of CsTPS1, CsTPS9, and CsTPPA was highest under at least one abiotic stress. These three genes may play a key role in abiotic stress responses. Most of the CsTPS and CsTPP genes that are closely located in the evolutionary tree have the same or similar functions. To our knowledge, this is the first paper that systematically reports the TPS and TPP gene families in cannabis.

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 P_N-PAR (P_Nmax), carboxylation efficiency (CE), the maximum net photosynthetic rate of the P_N-CO₂ (P^*_Nmax), carbon dioxide compensation point (CCP) and light respiration rate (R_p) of T. sinense in forest gap (FG) were higher than those in forest edge (FE) and understory (US). In FE, the net photosynthetic rate (P_N), light compensation point (LCP), LSP, P^*_Nmax of T. sinense were lower than those of Pterocarya stenoptera, while the LSP, P_Nmax, and saturation point of carbon dioxide (C_iast) 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 P_Nmax, 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.

Drought and salinity, which can alter the water balance, disrupt the ionic equilibrium, and create reactive oxygen species (ROS), are capable of destroying plant tissues. In this study, transcriptomics, proteomics, and metabolomics have been used to elucidate various abiotic stress responses. In transcriptional signaling pathways, abscisic acid (ABA) is one of the plant phytohormones that regulate the stress response. On the other hand, several regulons and factors of transcription contributed in the reaction to osmotic stresses, as well as in ABA-dependent/independent signaling pathways. However, the findings display that intricate molecular reaction of plants under stress conditions may be controlled by complicated regulative networks of gene expression and signal transduction, as well as by the interaction between them. From the point of view of proteomics, protein modifications in response to stress can be considered as a molecular tool to improve the resistance of plants to environmental stresses. These studies have provided new information about the significance of several gene and protein networks involved in the response of plants to salinity and drought, and the induction of tolerance. Moreover, identifying the crucial pathways which are involved in salinity and drought resistance can open doors for the establishment of commercial-resistant crop cultivars, and might be very useful in the next-generation crop breeding strategies to produce plants with salinity and drought-resistant traits.

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 (H_E = 0.386) and P. stipuleanatus (H_E = 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.

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.