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.

Abscisic acid (ABA) regulates various plant physiological processes, especially participates in the plant responses to harsh environments. The 9-cis-epoxycarotenoid dioxygenase (NCED) is a key enzyme in ABA biosynthesis pathway. Here, a TaNCED with an 1 887-bp open reading frame was cloned from wheat, which encodes a peptide of 628 amino acids. A chloroplast transit peptide sequence was found at the N-terminus of the TaNCED protein. Multiple sequence alignments indicate that the TaNCED protein shared high similarities with other NCEDs from different species. Real-time quantitative PCR analysis shows that expression of TaNCED was strongly up-regulated by treatments with ABA, polyethylene glycol, and drought stress, and it was down-regulated during germination of the wheat seeds. Ectopic overexpression of the TaNCED gene in Arabidopsis resulted in an increase of endogenous ABA and free proline content. A lower water loss rate and stomatal conductance of leaves were found in the transgenic plants in comparison with the wild type. Subsequently, the transgenic plants displayed an enhanced tolerance to drought stress but delayed seed germination. These data provide evidence that the TaNCED might play a primary role in regulation of ABA content during water stress and seed dormancy.

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.

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.

Seed germination and micropropagation protocols of the medicinal species Maytenus canariensis (Loes.) G. Kunkel & Sunding were optimized. In vitro seed germination occurred (86 to 94.7 %) only after treatment of the seeds with H₂SO₄, followed by surface sterilization and culture on solid nutrient medium without any growth regulators. Micropropagation failed when explants were taken from mature trees, and browning of the nutrient medium frequently occurred despite testing many growth media. Nonetheless, adventitious shoot regeneration was achieved employing axillary or apical buds taken from 2-2.5 months old plantlets obtained after in vitro germination of seeds, following culture on nutrient media supplemented with benzylaminopurine, kinetin and naphthalenacetic acid (NAA), attaining up to 3.9 shoots per explant, after 4-6 months. Root induction was best on a medium containing 4.0 mg dm^-3 NAA, achieving a 100 % induction. After hardening of rooted plants, survival after transfer to soil was 71.43 %.

Flood in rice fields at the time of seed sowing and early seedling establishment causes extensive crop loss due to the inability of the seeds to tolerate and overcome submergence. In the present study, rice genotypes from Assam, India tolerant to hypoxia during germination were identified through systematic screening of deep-water rice genotype collection from flood-prone ecosystem of Brahmaputra river valley. The difference in tolerance to hypoxia during germination within the species provides scope for identification of novel hypoxia-responsive factors involved in tolerance as mechanism of tolerance may not be conserved across tolerant germplasms. Tolerant genotypes were further subjected to physiological and molecular characterization. Growth rate kinetics in tolerant genotypes new Rangdhakekua bao (RKB) and cultivar Khao Hlan On (KHO) from International Rice Research Institute (IRRI) used as positive control exhibited stronger escape strategy under hypoxic condition compared to sensitive genotype IR-64 (negative control). Activities of α-amylase and pyruvate decarboxylase were significantly higher in RKB and KHO than in IR-64, while no significant difference was observed in the alcohol dehydrogenase activity. Reverse transcription quantitative PCR confirmed increased amounts of transcripts of sucrose nonfermenting 1 related protein kinase, myeloblastosis-related protein S1, rice amylase 3D, and trehalose phosphate phosphatase 7 genes, which are known to be involved in hypoxia signaling cascade. Besides, transcription factors (TFs) like ethylene responce factors 71 and 63, ethylene insensitive 3-like 1a and proteins like expansins A7 and A2, which are involved in cell elongation had also significantly higher amounts in RKB compared to IR-64. Additional factors that include TFs like ERF71 and ERF63 that shows perturbation at transcription even within tolerant genotypes might constitute the genotype-specific regulation, evolved as a part of its adaptive mechanism to survive under submerged conditions.

Seed germination and following seedling growth are largely affected by environmental conditions. However, the genes involved in adaptations to these conditions are largely unknown. In this study, we cloned and characterized an Arabidopsis uridine diphosphate glycosyltransferase gene UGT76E12 and investigated its function in seed germination and plant growth under adverse environments. We found that UGT76E12 gene expression was induced by NaCl, mannitol, and abscisic acid (ABA) treatments. Under these treatments, the UGT76E12 overexpression lines exhibited a delayed seed germination and cotyledon growth compared with a wild type, and this delayed growth could be restored by treatment with sodium tungstate, an ABA synthesis inhibitor. Further, real-time quantitative PCR analysis reveals that the stress-induced expressions of genes involved in ABA biosynthesis were greatly enhanced in the UGT76E12 overexpression lines. Therefore, our data suggest that the UGT76E12 gene plays an important role in regulation of seed germination and growth under adverse environmental conditions by affecting ABA biosynthesis.

Water transport across the cell membranes is regulated largely by a family of proteins known as aquaporins (AQPs). Plasma membrane intrinsic protein (PIP) is an important subfamily of plant AQPs localized on the plasma membrane. To investigate the molecular mechanism of water regulation in seed germination, seven genes encoding PIP were initially cloned and sequenced from the germinating seed cDNA pool of Brassica napus. They belong to the PIP1 and PIP2 subfamilies. The transcription of the seven cloned genes plus three previously identified AQP genes from B. napus were analyzed in different organs and different stages of seed germination by quantitative real-time PCR (qRT-PCR). The results show that the expressions of the ten AQP genes were lower or scarcely detected in dry seeds, but were up-regulated during germination as well as in young seedlings. In addition, the expression of these ten AQP genes in response to an abiotic stress during seed germination was investigated and the results also show differential responses to abiotic stress treatments. Our findings suggest that these ten genes play different roles during plant development and response to abiotic stresses in B. napus.

In plants, calcineurin B-like proteins (CBLs) and CBL-interacting protein kinases (CIPKs) regulate Ca2+ signalling and so responses to biotic and abiotic stresses. However, the details of specific CIPKs functions in various stress responses are poorly understood. Here, we report roles of dicot and monocot CIPK2 genes in response to salinity and heavy metals. Arabidopsis thaliana AtCIPK2 was found to be universally expressed in different tissues and organs and furthermore induced by salinity. Overexpression of AtCIPK2 or Tibetan Plateau wild barley (Hordeum spontaneum) HsCIPK2 in Arabidopsis alleviated toxic effects of NaCl and mercury on seed germination and root growth. Similarly, reduced toxic effects of copper and cadmium on seed germination, but not on root growth, were observed in these transgenic lines. Live-cell fluorescence imaging analysis revealed that HsCIPK2 was predominantly distributed in the cytoplasm and nucleus and weakly localized at the plasma membrane (PM), but its PM association was rapidly enhanced upon exposure to high salinity and mercury. These results suggest an involvement of CIPK2 in plant tolerance to salinity and mercury and provide a new insight into physiological functions of CIPKs in plant response to heavy metals.

Aquaporins control the specific transport of water and some other small molecules across membranes and are involved in various physiological processes. Plasma membrane aquaporins (PIPs) were shown to play an important role during tomato seed development. Therefore, we were interested in the participation of PIPs in seed germination and early seedling growth of wild type (WT) and the 7B-1 mutant, affected by blue light responses. We characterised the expression patterns of PIP-type aquaporin genes in these lines during different phases of seed germination and seedling growth after HgCl₂ (an aquaporin blocker) treatment. Further, we investigated whether blue radiation (BL) was involved in the regulation of these processes. Our experiments showed that 7B-1 mutant seed germination and root elongation are less responsive to HgCl₂ compared to WT. In both WT and 7B-1 mutant seeds, BL modulates the expression of PIP1;1 (upregulation) and PIP1;3 (downregulation) aquaporin isoforms. The PIP1;3 gene is downregulated not only by BL but also by HgCl₂ with a stronger effect in WT seeds. Thus, we show that BL can alter PIPs gene expression during tomato seed germination and seedling growth and that the 7B-1 mutation reduced the responsiveness to mercury blockage of aquaporins. Altogether, our data indicate that PIP aquaporins participate in tomato seed germination and radicle elongation and that the 7B-1 mutation and BL have an impact on these processes.

Circular RNAs (circRNAs), an emerging class of non-coding RNAs, are abundant in eukaryotic transcriptomes. Seed germination is one of the most important stages in the entire life cycle of plants that can be slowed down or totally restrained by high temperature. Our aim is to identify heat-responsive circRNAs and explore the potential function of circRNAs in tomato seeds at high temperature. Following high-throughput sequencing, 4 164 circRNAs were identified, and 980 circRNAs were shared in the control and high-temperature libraries. Among the 748 circRNAs with high expressions, 73 circRNAs were significantly up-/down- regulated in tomato seeds germinated at high temperature compared to the control. The parental genes of circRNAs existing in seeds only at high temperature were mainly involved in metabolic processes, cellular processes, catalytic activities, and binding based on Gene Ontology analysis. The results suggested that circRNAs were widespread in tomato and were generated from different chromosomes and diverse genomic regions. Some circRNAs in tomato seeds responded to high temperature during germination. This study provides the first genome-wide profile of circRNAs in response to high temperature during tomato seed germination and lays a foundation for studying the potential biological functions of circRNAs responding to heat stress.

Seeds of Citrus reticulata were germinated efficiently when they were sown directly after their extraction from fruits harvested in January, and incubated at constant temperature (25 °C). Seed drying decreased both the percentage of seed germination and the number of seedling per seed. Germination of seeds was better on Murashige and Skoog (MS) medium supplemented with 0.5 mg dm^-3 benzylaminopurine (BAP) than in a soil. Shoot cuttings obtained from germinated seeds were subcultured on B5 medium supplemented with 1 mg dm^-3 BAP, 0.5 mg dm^-3 kinetin (KIN) and 0.5 mg dm^-3 naphthalene acetic acid (NAA), where shoots grew and multiplied. They were rooted on half strength MS medium supplemented with 0.25 mg dm^-3 BAP, 0.5 mg dm^-3 NAA and 1 mg dm^-3 isobutyric acid (IBA). Rooting under light was better than under dark. Seedlings and shoot cuttings with roots were transferred successfully to the soil after three weeks of acclimatization.

A lot of pepper seeds having 87 % germination were subjected to X-ray inspection using a non lethal dose of radiation. Seeds with less than 2.7 % (on the basis of total seed area) of free space area, i.e. the spaces between embryo and endosperm, were classified as highly viable seeds (97-100 % germination) with the lowest level of abnormal seedlings. Seeds X-ray classified as good were subjected to a computerised image analysis to study seed imbibition and radicle elongation. The patterns of seed area increase, chosen as the most accurate indicator of seed swelling, resembled the triphasic curve of water uptake. The first phase was completed at 9 h followed by a second phase that varied widely in time until completion of germination between 52 and 96 h. The proportion of seeds with radicle protrusion between 52-56 h and 64-72 h assessed with the image analysis was significantly higher than that recorded using a conventional germination test. In addition, the rate of increase of seed area during the third phase of imbibition, mostly due to protrusion of the radicle tip and its growth, was highly correlated with the corresponding radicle elongation rate.

To further elucidate the molecular mechanism of the germination in common wheat, a differential proteomic analysis was completed between the F₁ hybrid RS5322 and its parental lines (RS53 and SN22) using isobaric tags for relative and absolute quantitation (iTRAQ) based strategy. Rapid grain germination and superior young seedling growth were observed in the F₁ hybrid line. A total of 807 differentially abundant proteins (DAPs) were identified by iTRAQ analysis of grains at 48 h after imbibition in distilled water. Bioinformatics analysis shows that 638 DAPs were annotated in 38 Gene Ontology functional groups, 764 DAPs were classified into 23 clusters of orthologous groups of protein categories, and 538 DAPs were enriched in 65 Kyoto encyclopedia of genes and genomes pathways. Real time quantitative PCR of 12 genes encoding different important proteins showed certain transcriptional and translational expression similarities during grain development. In the F₁ hybrid, the DAPs were particularly those involved in starch and sugar metabolism, protein metabolism, protein modification, and ubiquitin proteasome system (UPS). It was speculated that UPS might be responsible for a high germination ability in the F₁ hybrid by regulating storage substance metabolism. The DAPs identified in this study provide a scope for improving the grain germination trait in agricultural crops.

The allelopathic potential of two cultivars of sunflower (Helianthus annuus L.) Lech and Ogrodowy was studied. Leaf aqueous extracts of sunflower at 2.5, 5, and 10 % (m/v) concentrations were applied to determine their effect on mustard (Sinapis alba) seed germination and seedlings growth under laboratory conditions. Increasing concentration of aqueous extracts of sunflower inhibited seed germination, up to almost complete failure of germination, observed in the presence of 10 % extract from sunflower cv. Ogrodowy. The decrease in germinability was well correlated with increased membrane deterioration, assayed as electrical conductivity and enhanced lipid peroxidation, detected as increased malondialdehyde content.

Sunflower seeds behaved as chilling and freezing sensitive and also exhibited acclimation under low seed moisture content (< 1 %). At high seed moisture content (approx. 22 %) they tolerated chilling stress but failed to acclimate under freezing temperatures. Pre-imbibitional chilling (5 °C) or freezing (-5 or -10 °C) stress significantly enhanced total soluble protein (TSP) content. Chilling treatment after imbibition (in contrast to pre-imbibition) enhanced germination and this was accompanied by increase in 30, 24 and 21.9 kDa TSPs content (3 d after germination). Freezing at -5 and -10 °C suppressed seed germination and increased content of 78 and 56.2 kDa wall bound proteins. Chilling acclimation decreased 35.4, 33.9, 29.5, 23.4 and 21.4 kDa TSPs.

Burial and removal techniques with seeds bags were used to examine the Eucalyptus victrix seed longevity. Seeds kept in room temperature (control) had 94% germination within 25 d, however, with increasing duration of burial the E. victrix seed viability decreased to zero before 142 d. Similarly, seed buried in shade and open had no significance difference in germination.

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.

Durum wheat (Triticum turgidum L. var. durum) is mainly produced under rainfed but often sub-optimal moisture conditions in the Mediterranean basin. A set of 114 durum wheat recombinant inbred lines (RILs) developed from the cross of cultivars Omrabi5 × Belikh2 were tested for the ability to tolerate moisture deficiency at the germination and early seedling growth stage. The stress was imposed by exposing the germinating grain to 12 % polyethylene glycol. It induced a measurable reduction in root length, shoot length, and the percentage of normal seedlings. The germination and seedling growth of Belikh2 were more strongly inhibited than those of Omrabi5, and both parents were outperformed by > 50 % of the RILs. A quantitative trait locus (QTL) analysis was carried out by first assembling a linkage map from 265 informative microsatellites. Composite interval mapping revealed nine QTL spread over seven chromosomes. Five of these were associated with coleoptile length, and one of the five explained nearly 29 % of the relevant phenotypic variance. The coleoptile length was significantly correlated with the seedling growth, plant height, and thousand kernel mass derived from field-grown plants of the same RIL population.

Drought is one of the main factors restricting seed germination. In order to reveal the physiological and molecular mechanisms of improved germination ability in upland rice under drought stress, we investigated the seed germination characteristics and the expression of genes related to gibberellic acid (GA₃), α-amylase, and expansin of upland rice cultivar IRAT109 and lowland rice cultivar Yuefu under drought stress induced by 15 % (m/v) polyethylene glycol (PEG) and GA₃ application. Seed germination decreased in upland rice and lowland rice under PEG-induced stress; upland rice was less affected than lowland rice. The germination vigour, root length, and shoot length were significantly higher in upland rice than in lowland rice under PEG stress. The GA₃/abscisic acid ratio, α-amylase activity, and soluble sugar content in the germinated seeds were higher in upland rice. An RNA sequencing analysis revealed that 14 genes related to gibberellins, α-amylase, and expansin had a significantly higher expression in upland rice than in lowland rice. On the other hand, application of GA₃ significantly increased the germination vigour, shoot length, root length, α-amylase activity, and soluble sugar content in upland rice. It also induced higher expressions of α-amylase and expansin related genes in upland rice. The results indicate that GA₃ plays an important role in promoting seed germination in upland rice under drought stress by increasing the expressions of α-amylase and expansin genes.

Aquaporins (AQPs) are proteinaceous channels known to regulate transmembrane water transport, and therefore may be important component of imbibition during osmopriming and germination. To explore the association between AQPs and osmopriming-led enhanced germination performance, we studied the expression patterns of four spinach (Spinacia oleracea) AQP coding genes (SoPIP1;1, SoPIP1;2, SoPIP2;1, and SoδTIP) during osmopriming and subsequent germination under optimal conditions, chilling and drought. All these genes were up-regulated within 2-4 d of priming (phase II-imbibition). We hypothesize such up-regulation to facilitate the pressure potential-driven cell expansion and increase germination potential of primed seeds. Our data during post-priming germination suggest that SoPIP1;1 and SoδTIP were more closely associated with enhanced germination performance. In general, all AQPs were downregulated under chilling and drought. However, under chilling, SoPIP2;1 was expressed at relatively higher level in primed seeds that also exhibited greater chilling tolerance, while SoPIP1;2 and SoδTIP exhibited opposite pattern. Similarly, SoPIP1;1, SoPIP2;1, and SoδTIP exhibited higher expression in primed seeds that also had greater drought tolerance.

Zeaxanthin epoxidase (ZEP) plays important roles in plant growth and development due to its functions in abscisic acid (ABA) biosynthesis and in the xanthophyll cycle. Many studies have been exploring the roles of ZEP in seed germination and response to various environmental stresses. In this study, we reported that heterologously overexpressing the ZEP gene from Medicago sativa (MsZEP) in tobacco increased ABA content in tobacco mature seeds and negatively regulated seed germination. Enhanced ABA synthesis in seed embryo and delayed germination might also be related to the increased 9-cis-epoxycarotenoid dioxygenase (NCED6) expression. Moreover, we found that overexpression of MsZEP resulted in an increased expression of the SOMNUS gene but a decreased expression of the DNA ligase 6 gene (Lig6) suggesting that MsZEP might affect seed proteome and DNA integrity. Furthermore, enhanced chlorophyll content in transgenic tobacco seedlings overexpressing MsZEP might be due to its function in the xanthophyll cycle and ABA biosynthesis.

Hemp (Cannabis sativa L.) seeds have been recognized as a nutritional protein source for humans and animals. In this study, gene families encoding precursor polypeptides of three storage protein classes, including six 11S edestin, two 2S albumin and one 7S vicilin-like genes were identified and characterized from an inbred line of hemp. All edestins showed typical 11S globulin features but based on the amino acid composition, they were grouped in three edestin types (type1, -2 and -3). Genes encoding edestin type1 and -3, were very close to each other in a DNA fragment of 16 071 bp, whereas the two isoforms of edestin type2 were linked on a different DNA fragment of 8 232 bp and arranged in a tailto- tail fashion. All edestin types were very rich in arginine and glutamic acid, but edestin type3 was the richest in cysteine and methionine. Regarding the 2S albumin (Cs2S) two genes were identified in a fragment of 13 738 bp in a tail-to-head array. Finally, only one 7S-vicilin like gene (Cs7S) that exhibited typical 7S vicilin features such as the presence of two cupin domains and several N-glycosylation sites was isolated. Southern blot hybridization is in agreement with the number of genes isolated, and real-time qPCR analysis revealed that all genes are expressed in the seed. The highest expression was observed for edestin type1 (CsEde1) and Cs2S, whereas the lowest expression was detected for Cs7S. The results of this study provide a complete overview of the genes encoding hemp storage proteins and significantly advance our knowledge on the organization of these gene families.

The activities and isoenzyme pattern of catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD) have been studied during germination of Chenopodium murale seeds. CAT and SOD activities were similar in dry seeds and during first 2 d of imbibition. CAT activity increased during radicle protrusion and early seedling development. The maximum SOD activity was found at final stages of germination and early seedling development. POD activity was not detected until the 6^th day of germination, indicating POD involvement not until early seedling development. Gibberellic acid (GA₃, 160 µM) delayed and synchronized C. murale germination.

Effects of H₂S on seed germination under chromium (Cr) stress were investigated in wheat (Triticum aestivum L.). Under Cr stress, the percentage of germination of wheat seeds decreased, but this decrease could be alleviated by pretreatment with NaHS, an H₂S donor, in a dose-dependent manner. Furthermore, NaHS significantly enhanced the activities of amylase, esterase, superoxide dismutase, catalase, ascorbate peroxidase, and guaiacol peroxidase in Cr-stressed germinating seeds, whereas reduced the Cr-induced increase in lipoxygenase activity and over-production of malondialdehyde (MDA) and H₂O₂, and sustained slightly higher content of endogenous H₂S.

Background: Platycladus orientalis L. is a drought-tolerant conifer valued for its ornamental and medicinal properties. However, efficient regeneration systems for this species remain limited, hindering its propagation and conservation. Aims: The aim of this study was to develop a reliable protocol for indirect organogenesis of Platycladus orientalis under in vitro conditions, evaluating the influence of explant type, culture medium, light exposure, and pretreatment on regeneration efficiency. Methods: Cotyledon, hypocotyl, and radicle explants were cultured on different media formulations. The effects of light and darkness during callus induction and shoot elongation were compared. Seeds underwent or avoided vernalization and scarification treatments to assess their influence on germination and callus formation. Results: Cotyledon explants achieved the highest callus induction rate, reaching 74.06%, particularly under dark conditions. Exposure to light during elongation significantly enhanced callus proliferation and shoots differentiation. Quoirin and LePoivre medium promoted the greatest number of adventitious shoots, with an average of 7.9 shoots per explant, while other media tested showed lower effectiveness. Germination was higher in non-vernalized and non-scarified seeds cultured in Quoirin and LePoivre medium. Conclusions: The established protocol enables efficient indirect organogenesis and shoot regeneration of Platycladus orientalis using cotyledon explants and Quoirin and LePoivre medium. The finding provides a valuable tool for clonal propagation and conservation of this species, supporting both ornamental cultivation and the preservation of its genetic resources.

Background: The tomato brown rugose fruit virus (Tobamovirus fructirugosum, ToBRFV) is an emerging tobamovirus that has quickly become a significant obstacle to the production of tomatoes and peppers worldwide. It is now classified as a regulated quarantine pathogen. Effective containment requires rapid, reliable, inexpensive, and safe diagnostic protocols for routine screening in laboratories and production systems.
Aims: We aimed to thoroughly evaluate integrated molecular and serological diagnostic methods for ToBRFV and develop biosafe positive controls suitable for high-throughput and decentralized applications.
Methods: We evaluated the following methods: conventional RT-PCR, one-enzyme RTX-PCR, immunocapture RT-PCR, recombinase polymerase amplification, loop-mediated isothermal amplification with colorimetric detection, Western blotting, dot blot, and tissue blot immunoassay. The non-infectious positive control was prepared using the GoldenBraid 3.0 cloning system. We developed a single-seed assay that enables direct testing of tomato seed stocks.
Results: Among the evaluated molecular methods, RTX-PCR was particularly advantageous due to its minimal sample handling, reduced cost, and ability to bypass RNA extraction. The tissue blot immunoassay enabled high-throughput, low-cost screening of hundreds of samples per day using only basic equipment. Although ToBRFV was frequently detected in seeds harvested from infected plants, no systemic infection was observed in progeny seedlings, confirming the low rate of true vertical transmission. A non-infectious positive control was prepared and successfully employed in molecular methods.
Conclusions: Our findings provide an integrated diagnostic framework combining molecular, serological, and biosafety tools to effectively monitor and contain ToBRFV in commercial production and phytosanitary settings.

Thioredoxins (Trx) are small multifunctional redox proteins that contain thioredoxin conserved domain and active site WCXXC. The Trx family has an important role in multiple processes, including electron transport, seed germination, redox regulation, biotic and abiotic stresses resistance, etc. Although Trx genes have been extensively characterized in some plants, they have not been reported in peanut until now. The identification of AhTrx genes provides potential candidate genes for studying their effects and regulatory mechanisms in peanut (Arachis hypogaea L.) growth and development, especially under aluminium (Al) stress. It is also helpful to further analyze the Al resistance pathway in plants. Seventy AhTrx genes were identified using a genome-wide search method and conservative domain analysis. Then the basic physicochemical properties, phylogenetic relationship, gene structure, chromosomal localization, and promoter prediction were studied by the bioinformatic methods. Furthermore, the expressions of AhTrx genes under different Al treatment times in two peanut cultivars were tested using a real-time quantitative polymerase chain reaction. Seventy AhTrx genes were identified and characterized. Phylogenetic tree analysis showed that all AhTrx members could be classified into 9 groups with different conserved domains. Motif 1 was found to exist in every sequence, with an active site. Furthermore, the gene structures showed that the AhTrx family was complicated and changeable during evolution. The chromosomal localization indicated that the distribution and density of the Trx family on 20 peanut chromosomes were uneven. Predictive promoter analysis indicated that AhTrx proteins might play a role in phytohormones synthesis and stress response. Finally, the expression patterns of the AhTrx genes showed that every gene was differently expressed under Al treatment in different peanut cultivars, some were obvious, others had no significant difference, some were at a high level, while others were at a low level. This study systematically identifies the Trx gene family in peanut, providing some candidates for further study on its effects and regulatory mechanism under Al stress in peanut.

Saccharides are a direct energy source for most organisms and the primary components in grains of common wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD). However, genes involved in the metabolism of primary saccharides such as glucose and fructose have not been fully characterized in wheat, which limits our understanding of how these genes influence wheat growth. In this study, genes coding ATP-dependent phosphofructokinase (PFK), fructose-1,6-bisphosphatase (FBP), and pyrophosphate-dependent fructose-6-phosphate 1-phosphotransferase (PFP), which participate in the conversion between fructose 6-phosphate (F-6-P) and fructose 1,6-bisphosphate (F-1,6-P₂), were identified at the genome-wide level. A total of 24, 13, and 12 genes were found encoding TaPFK, TaFBP, and TaPFP, respectively. All predicted peptides of these genes exhibited conserved substrate-binding domain, suggesting they are active enzymes in vivo. Transcriptome data ranked the gene levels as follows: TacyFBP-1 > TacpFBP-1 > TaPFPα-2 ≈ TaPFPβ >> TaPFK-1 ≈ TaPFK-5 >> all remaining genes at different developmental stages of wheat. In the three tapfp-a, b, and d knockout lines, there was a decrease in the plant height, anther length, and thousand-grain mass, while the percentage of abnormal pollen increased compared to that of wild type cv. Huapei3 (HP3). During germination, tapfpβ-a exhibited a lower germination rate, shorter coleoptile and primary root length, and higher fructose content than HP3, tapfpβ-b, and tapfpβ-d lines. Expressions were ranked as follows: TaPFK-5 ≈ TaPFPα-2 >> TaPFPα-1 ≈ TaPFPβ > TacyFBP-1 ≈ TaPFK-7, 9 in HP3. All these genes were downregulated during the 24 - 96 h germinating process in three mutant lines. Collectively, main TaPFK, TaFBP, and TaPFP members cooperated during wheat growth, while TaPFPβ knockout decreased wheat vitality. Results from this study can aid more systematic studies of the physiological and molecular functions of TaPFK, TaFBP, and TaPFP.

Dimorphic seeds of Atriplex prostrata were removed from cold dry storage monthly over a one year period to test for fluctuations in seed dormancy and germination rate. For each seed type, four replicates of 25 seeds were exposed to four alternating night/day temperature regimes mimicking seasonal fluctuations in Ohio: 5/15 °C; 5/25 °C; 15/25 °C and 20/35 °C with a corresponding 12-h photoperiod (20 μmol m^-2 s^-1; 400 - 700 nm). We found a significant three-way interaction of seed size, temperature and month for both percent germination and the rate of germination. Large seeds showed the greatest germination at the 20/35 °C and 5/25 °C temperature regimes and small seeds at the 5/25 °C regime. Large seeds had greater germination at all temperatures as compared to small seeds. Large seeds had the fastest germination rates at 20/35 °C followed by 5/25 °C whereas small seeds had the fastest rates at 5/25 °C followed by 20/35 °C.