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At least 19 recordsLinked to original sources
PubMed1977

Effect of volatile and gaseous exudates of germinating seeds of some plants on the germinative potentialities of some fungal spores in relation to their ability of absorption of some sugars and nitrogen sources.

Volatile and gaseous exudates of germinating seeds of Z. mays, P. armeniaca, C. sativus, and C. olitorius stimulated the spore germination of B. piluliferum. This stimulation was accompanied with an increase in sugar and nitrogen source absorption during the spore germination. On the other hand, the volatile and gaseous exudates of the germinating seeds of P. sativum inhibited the absorption of both sugar and nitrogen source, as well as the percentage of spore germination. In case of B. cinerea, the effect of the volatile and gaseous exudates of the germinating seeds of all plants used on the fungal spore germination differed according to both the sugar and nitrogen source absorbed.

Absorption↗
PubMed2026

Positive feedback loop between RAF12 and ABI5 reinforces ABA-mediated suppression of Arabidopsis seed germination.

ABA-INSENSITIVE 5 (ABI5) is a key transcriptional regulator mediating abscisic acid (ABA)-induced suppression of seed germination. However, the downstream regulatory network through which ABI5 exerts its function remains incompletely understood. Here, by integrating ChIP-seq and RNA-seq analyses, we identify RAF12, a member of the B2 Raf-like kinase subfamily, as a direct transcriptional target of ABI5. ABI5 binds to the RAF12 promoter and activates its expression. Loss-of-function raf12 mutants exhibit reduced sensitivity to ABA during seed germination, suggesting a negative regulatory role for RAF12 in this process. Conversely, RAF12 interacts with and phosphorylates ABI5, thereby enhancing its transcriptional activity. Further analysis showed that RAF12 regulates its own kinase activity through autophosphorylation. Mutations at its phosphorylation sites significantly weaken its ability to enhance ABI5's transcriptional activity. Together, these findings uncover a positive feedback loop wherein ABI5 transcriptionally activates RAF12, which in turn reinforces ABI5 activity through phosphorylation. This module may function in parallel with the canonical SnRK2s-ABI5-mediated ABA signaling cascade, offering new mechanistic insights into the fine-tuning of ABA responses during seed germination.

Arabidopsis↗
PubMed2026

Structural and functional characterization of peanut expansin proteins identifies AhEXPA3 as a stress-responsive regulator of seed germination.

Expansins are cell wall-associated proteins that play important roles in plant growth, development, and environmental responses, yet their structural features and functional significance in peanut remain insufficiently understood. Here, we performed a genome-wide identification and characterization of 70 expansin proteins in cultivated peanut. Phylogenetic analysis classified these genes into four subfamilies (EXPA, EXPB, EXLA, and EXLB), with conserved motif patterns and subgroup-specific exon-intron structures. Collinearity and evolutionary analyses revealed that segmental duplication mainly drove peanut expansin family expansion, with most duplicated gene pairs subsequently undergoing purifying selection. Promoter analysis identified abundant cis-regulatory elements associated with light responses, hormone signaling, and stress responses. Expression profiling indicated that many AhEXP genes were differentially expressed during seed germination and in response to abscisic acid (ABA), salt, and osmotic stresses. Among them, AhEXPA3 was identified as a stress-responsive expansin protein with marked transcriptional induction under abiotic stress conditions. Subcellular localization analysis suggested that AhEXPA3 exhibits an endoplasmic reticulum-associated localization pattern. Functional assays further demonstrated that heterologous expression of AhEXPA3 inhibited seed germination and early seedling establishment under stress conditions in both Arabidopsis thaliana and rice. These findings support a negative regulatory role of AhEXPA3 in stress-responsive seed germination and broaden current understanding of expansin protein function in legumes.

Germination↗
PubMed2026

Comprehensive characterization of the genes in AP2/ERF family and their involvement in salt-alkali stress response during Nelumbo nucifera seed germination.

Nelumbo nucifera Gaertn. is an economically and ecologically important aquatic plant, but its growth and productivity are severely constrained by soil salinization and alkalization. AP2/ERF transcription factors are key regulators of plant abiotic stress responses; however, their roles in salt-alkali tolerance in N. nucifera remain largely unclear. In this study, we performed a genome-wide identification and characterization of the AP2/ERF gene family in N. nucifera, followed by phylogenetic, structural, and physicochemical analyses. A total of 101 AP2/ERF genes were identified and classified into five subfamilies, showing both evolutionary conservation and species-specific divergence compared with Arabidopsis thaliana. Physiological analyses during seed germination under salt-alkali stress revealed significant changes in malondialdehyde content, proline accumulation, and antioxidant enzyme activities, suggesting activation of oxidative stress defense and osmotic adjustment mechanisms. Transcriptome profiling of seedlings treated with 150 mM salt-alkali solution for 5 and 10 days identified 7,350 differentially expressed genes, including 29 AP2/ERF members responsive to stress. Among them, 13 genes, including AP2-9, ERF23, ERF15, ERF31, ERF34, and DREB21, were consistently upregulated under both treatments, indicating their potential roles in stress adaptation. qRT-PCR validation further confirmed the sustained upregulation of key genes AP2-9, ERF23, ERF34, and DREB21, consistent with transcriptome data. Overall, this study provides the first comprehensive overview of the AP2/ERF gene family in N. nucifera and identifies candidate regulators involved in salt-alkali stress responses, offering valuable insights into the molecular mechanisms of stress adaptation and potential genetic resources for breeding salt-alkali tolerant aquatic plants.

AP2/ERF transcription factors↗
PubMed1978

Purification and properties of beta-mannanases I and II from the germinated seeds of Trifolium repens. Mode of galactomannan degradation in vitro.

Two beta-mannanases (beta-mannosidases, EC 3.2.1.25) purified from the germinated seeds of Trifolium repens by a procedure that included chromatography on hydroxyapatite, gel filtration on acrylamide/agarose (Ultragel 5/4) and preparative polyacrylamide-gel-electrophoresis. The final purification step completely resolved two beta-mannanases with distinct specificities, which were termed beta-mannanase I and beta-mannanase II. beta-Mannanase I was purified 1400-fold and beta-mannanase II 1000-fold. The purified enzymes showed a single protein band when examined by polyacrylamide-gel disc electrophoresis. beta-Mannanase I, apparent mol.wt. 43 000, accounted for 49% of the total activity recovered from the final step of purification. beta-Mannanase II, apparent mol.wt. 38 000, accounted for the remaining 51% of activity. Molecular-weight determinations were by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and by the electrophoretic method of Hendrick & Smith [(1968) Arch. Biochem. Biophys. 126, 155-164]. The substrate specificities of both enzymes were examined with the galactomannans of T. repens and of Medicago sativa, as well as with manno-oligosaccharides. The pH optimum was between pH 5.1 and 5.6 for both enzymes.

Enzyme Activation↗
PubMed2026

Dual Roles of RAD23b and RAD4 on the Desiccation Tolerance of Germinated Seeds.

Desiccation tolerance (DT) is a survival trait enabling orthodox seeds to withstand extremely low water content. While some protective factors are characterised, it remains mechanistically obscure. Here, based on PEG-induced DT re-establishment in germinated Brassica napus L. seeds, we investigated the dual functions of nucleotide excision repair (NER) components RAD23b and RAD4 in DNA repair and transcriptional regulation of root development. PEG pre-treatment alleviated dehydration-induced DNA damage and activated NER genes, suggesting the involvement of NER in seed DT. Unexpectedly, Arabidopsis atrad23b mutant and BnRAD23b/BnRAD4 over-expressing seeds all exhibited significantly decreased DT after dry back, which evoked a hypothesis that BnRAD23b-BnRAD4 functions beyond NER. Normally, BnRAD4 interacted with BnRAD23b and repressed the expression of root development genes NAC103, EMB1444, RRA1 by directly binding to STRE elements within their promoters. Dehydration stress alleviated this repression, drove transcriptional reprogramming and might redirect the complex to execute DNA repair. Genetic analyses revealed that germinated seeds of atnac103, atemb1444, and atrra1 single mutants all exhibited reduced DT, and double mutants under atrad23b background almost abolished DT. This study suggests that RAD23b and RAD4 may regulate DT re-establishment of germinated seeds through balancing genome integrity and radicle development, with implications for DT study broadly.

Brassica napus L.↗
PubMed1979

Some properties of starch phosphorylase from cotyledons of germinating seeds of Voandzeia subterranea.

Two isoenzymes (Forms I and II) of starch phosphorylase (1,4-alpha-D-glucan: orthophosphate alpha-glucosyltransferase, EC 2.4.1.1) were found in cotyledons of germinating seeds of Voandzeia subterranea L. Thouars. Phosphorylase I, which was the major component, had a pH optimum of 5.5--5.6, whereas phosphorylase II had a pH optimum of 6.1--6.3. Phosphorylase I had a molecular weight of 204 000 +/- 4000 and a subunit molecular weight of about 95 000. Phosphorylase I was stimulated by Mg2+, Mn2+, AMP, cyclic AMP, pyruvate and EDTA, but inhibited by Fe2+, Cu2+, Zn2+ and ATP. Stimulation of phosphorulase I by AMP was accompanied by changes in the affinity of the enzyme for glucose-1-phosphate in the presence of increasing AMP concentrations, and of AMP in the presence of increasing glucose-1-phosphate concentrations. Double-reciprocal plots of initial velocity data were non-linear (convex up) at low glucose-1-phosphate concentrations but became linear in the presence of AMP or ATP. Double-reciprocal plots were linear at high glucose-1-phosphate concentrations in the absence or presence of modifiers.

Adenosine Monophosphate↗
PubMed1979

Germinating seed in anterior chamber. Report of an unusual case.

A seed introduced into the eye of an 8-year-old boy through a penetrating corneal wound became embedded in the iris. Many months later it germinated. The germinating seed was successfully removed from the iris and anterior chamber with retention of excellent visual acuity. The seed was identified as a dicotyledonous seedling of the family Compositae.

Anterior Chamber↗
PubMed1979

Lipid metabolism in germinating seeds. Purification of ethanolamine kinase from soya bean.

Ethanolamine kinase has been purified to homogeneity from germinating soya bean (Glycine max L.) seeds. The purified enzyme had a molecular weight of 17--19 000 as estimated by gel filtration and sodium dodecyl suphate-polyacrylamide gel electrophoresis. It would not phosphorylate choline, had a Km for ethanolamine of 8 microM and utilised Mg-ATP. The kinase could be purified in a 37 000 molecular weight form (dimer) which would easily dissociate on storage. In contrast to ethanolamine kinase whose activity was unaffected by the presence of choline in the assay system, soya bean choline kinase, although not phosphorylating ethanolamine, was competitively inhibited by the latter. The purification of specific choline and ethanolamine kinases from germinating soya bean confirmed in vivo observations which had indicated separate enzymes.

Choline↗
PubMed1979

Levels of aminoacyl-tRNA synthetases, tRNA nucleotidyltransferase and ATP in germinating lupin seeds.

Transfer RNAs in dry lupin seeds are aminoacylated to a low extent (Kedzierski, W. and Pawełkiewicz, J. (1977) Phytochemistry 16, 503-504) and are partly degraded at the acceptor terminus (Dziegielewski, T. and Pawełkiewicz, J. (1977) Bull. Acad. Polon. Sci. Ser. Biol. 7, 4oo-435). Increase in the levels of tRNA aminoacylation and disappearance of defective tRNA molecules during seed germination are not accompanied by significant changes in the levels of phenylalanyl-, arginyl-, valyl-tRNA synthetases and tRNA nucleotidyltransferase. Additionally, no inhibitor of aminoacylation of valine tRNA has been detected in dry seeds. However, dry seeds contain very low ATP amounts, which increase dramatically during germination. The above results suggest that a very low ATP level is a factor limiting the aminoacylation and reparation of tRNA molecules at early stages of seed germination.

Adenosine Triphosphate↗
PubMed2025

Integrated 16 S rRNA and transcriptome analysis reveal molecular and microbial mechanisms of cold-tolerant germination in hulless barley.

BACKGROUND: Elucidating the mechanisms underlying cold-tolerant germination is crucial for enhancing crop resilience to low temperatures. Hulless barley (Hordeum vulgare var. coeleste L.), with remarkable natural cold adaptation, serves as an ideal model to study cold stress tolerance mechanisms in gramineous crops. In this study, cold-tolerant variety 37 and cold-sensitive variety 44 were screened and used to investigate the molecular mechanisms of cold-tolerant germination, via seed germination assays, combined with phytohormone determination, transcriptome sequencing and 16 S rRNA amplicon sequencing. RESULTS: Low temperature significantly inhibited hulless barley seed germination: the germination rate of cold-sensitive variety 44 decreased by 69%, while that of cold-tolerant variety 37 only decreased by 2%. Transcriptome analysis identified 2,647 and 2,392 differentially expressed genes (DEGs) in variety 37 and 44, respectively. Weighted gene co-expression network analysis (WGCNA) revealed a green module significantly positively correlated with gibberellic acid (GA) content, containing 10 core genes such as late embryogenesis abundant protein (LEA) and Homeobox genes. 16 S rRNA sequencing showed that the cold-tolerant variety 37 had enriched abundances of dominant endophytes including Sphingomonas and Pelomonas, with correlation coefficients of 0.70 and 0.87 with GA content, respectively. Additionally, exogenous GA treatment significantly increased germination rates under cold stress by 176.67% in cold-sensitive variety 44. CONCLUSIONS: This study confirms that the enhanced cold tolerance of hulless barley during seed germination originates from the synergistic interaction between beneficial endophytes (Sphingomonas, Pelomonas), GA, and core genes (e.g., LEA, Homeobox). Exogenous GA application can significantly restore the germination ability of cold-sensitive varieties. These findings provide a critical theoretical basis for improving cold tolerance in hulless barley germplasm.

Hordeum↗
PubMed2025

ODR1, the key seed dormancy and germination regulator, promotes seed Proanthocyanidin biosynthesis via interaction with TTG1 and modulation of MBW complex activity.

Seed dormancy and germination are crucial for both plant survival and reproduction and for crop sowing and harvesting. Proanthocyanidins (PAs), one of the most abundant seed metabolites, play a role in enhancing dormancy and inhibiting germination. Multiple regulatory factors involved in PAs biosynthesis can alter seed dormancy or germination capacity. However, whether the dormancy or germination factors reciprocally influence the PAs biosynthesis is unclear. Here, we report that ODR1, a seed dormancy and germination key factor and a transcriptional (co-) repressor, can regulate seed PAs biosynthesis and act as a transcriptional co-activator. The odr1 mutant shows lighter seed coat color, decreased PAs contents, and reduced expression of PAs biosynthesis genes, which are restored in the ODR1 complementary lines. ODR1 interacts with TTG1 and forms a complex with TTG1/TT2/TT8 (three MBW complex components), enhancing their activation on promoters of PAs biosynthesis genes like DFR and ANS. Overexpressing TTG1 in the odr1-2 mutant rescues or even reverses PA-related phenotypes of odr1-2, confirming that ODR1-mediated regulation of PAs biosynthesis is dependent on TTG1. Moreover, three homologous copies of ODR1 in rapeseed were identified, and simultaneous knockout of them reduces the PAs contents. These results revealed the previously uncharacterized functions of ODR1 in PAs biosynthesis, suggested its conservation between Arabidopsis and rapeseed, and provided important gene resources for rapeseed variety improvement.

Proanthocyanidins↗
PubMed1975

Toxicological implications of pesticides: their toxic effects on seeds of food plants.

Pesticides are widely used for the protection of economic crops from a variety of noxious pests. The repeated and indiscriminate uses and the extreme stability of certain pesticides have led to their accumulation in plants, animals, soils and sediments, thus effecting widespread contamination of the environment. Soil contaminants are especially serious because they can inhibit or impair the seed germination of our food and feed crops. Seeds can come in close contact with pesticides through processes such as prematurity application, fumigation, seed dressings, and seed treatments. Several reports have indicated the toxic effects of pesticides on seed germination. Possible mechanisms of the toxic action on pesticides during the germination of seeds have been discussed with emphasis on biochemical, histological, and cytological alterations. Bioassay procedures employing seed germination as a smiple, feasible, economical, time-saving indicator of toxicity have been described briefly. Attention is then drawn to the possible potential health hazards arising from the presence of pesticidal chemicals in food plants since the toxicological implications of long term exposure to pesticides are often more far-reaching.

Animals↗
PubMed1977

Some characteristics of soluble fatty acid synthesis in germinating pea seeds.

Soluble fractions from germinating pea synthesize palmitic acid de novo and stearic acid by elongation. Malonyl CoA, acyl carrier protein and NADPH are required for both reactions. In contrast to some other plant systems, no requirement was found for divalent cations. On the other hand, the formation of both stearate and palmitate was inhibited by sulphydryl reagents and palmitate elongation was sensitive to arsenite. The products of the reactions were examined and found to be principally acyl-acyl carrier proteins and unesterified fatty acids. Unlike the pea microsomal fractions, the soluble enzymes are stimulated only slightly by the addition of exogenous lipids. The substrate for palmitate elongation is palmitoylacyl carrier protein, which is quantitatively elongated to stearate. Comparisons are made with membrane-localised fatty acid synthesis from the same tissue.

Arsenic↗