Genome-wide identification of TCP transcription factors and their potential roles in hydrolyzable tannin production in Quercus variabilis cupule.

Hydrolyzable tannins (HTs) have garnered significant attention due to their proven beneficial effects in the clinical treatment of various diseases. The cupule of Chinese cork oak (Quercus variabilis Blume) has been used as raw material of traditional medicine for centuries for its high content of HTs. Previous studies have identified UGT84A13 as a key enzyme in the HT biosynthesis pathway in Q. variabilis, but the transcriptional regulation network of UGT84A13 remains obscure. Here, we performed a comprehensive genome-wide identification of the TCP transcription factors in Q. variabilis, elucidating their molecular evolution and gene structure. Gene expression analysis showed that TCP3 from the CIN subfamily and TCP6 from the PCF subfamily were co-expressed with UGT84A13 in cupule. Further functional characterization using dual-luciferase assays confirmed that TCP3, rather than TCP6, played a role in the transcriptional regulation of UGT84A13, thus promoting HT biosynthesis in the cupule of Q. variabilis. Our work identified TCP family members in Q. variabilis for the first time, and provided novel insights into the transcriptional regulatory network of UGT84A13 and HT biosynthesis in Q. variabilis, explaining the reason why the cupule enriches HTs that could be used for traditional medicine.

Characteristic of epicotyl dormancy and its hormonal regulation in Chinese cork oak (Quercus variabilis).

Emergence heterogeneity caused by epicotyl dormancy contributes to variations in seedling quality during large-scale breeding. However, the mechanism of epicotyl dormancy release remains obscure. We first categorized the emergence stages of Chinese cork oak (Quercus variabilis) using the BBCH-scale. Subsequently, we identified the key stage of the epicotyl dormancy process. Our findings indicated that cold stratification significantly released epicotyl dormancy by increasing the levels of gibberellic acid 3 (GA3) and GA4. Genes associated with GA biosynthesis and signaling also exhibited altered expression patterns. Inhibition of GA biosynthesis by paclobutrazol (PAC) treatment severely inhibited emergence, with no effect on seed germination. Different concentrations (50 µM, 100 µM, and 200 µM) of GA3 and GA4+7 treatments of germinated seeds demonstrated that both can promote the emergence, with GA4 exhibiting a more pronounced effect. In conclusion, this study provides valuable insights into the characterization of epicotyl dormancy in Chinese cork oak and highlights the critical role of GA biosynthesis in seedling emergence. These findings serve as a basis for further investigations on epicotyl dormancy and advancing large-scale breeding techniques.

ABA exerts a promotive effect on the early process of somatic embryogenesis in Quercus aliena Bl.

Quercus aliena, a native Chinese tree species, is significant in industry and landscaping. However, it is traditionally propagated by seeds with many limitations, such as pest infestations, seed yield and quality. Thus, this study firstly introduces a somatic embryogenesis (SE) system for Q. aliena, enhancing its cultivation prospects. Thereinto, the development stage of zygotic embryo had a significant effect on SE, only immature embryos in 10-11 weeks after full bloom (WAF), rich in endogenous abscisic acid (ABA), could induce SE. Exogenous application ABA had positive roles in the early development process of both primary and secondary SE, while its antagonist had opposite roles. Transcriptome analysis showed that transcription regulation occupied the major position. Mfuzz cluster and WGCNA co-expression analysis showed that 24 candidate genes were involved in the SE process. The expression of the 24 genes were also affected by exogenous ABA signals, among which QaLEC2, QaCALS11 and QaSSRP1 occupied the important roles. Additionally, the callose content were also affected by exogenous ABA signals, which had significantly positive correlations with the expression of QaLEC2 and QaCALS11. This study not only established an efficient reproduction system for Q. aliena, but also revealed the difference in embryogenic ability of zygotic embryos from the aspects of transcriptome and endogenous hormone content, and lay a foundation for clarifying the molecular mechanism of SE, and provided a reference for exploring the vital roles of ABA in SE.

Genome-Wide Identification of GAST Family Members and Their Potential Roles in Epicotyl Dormancy in Chinese Cork Oak (Quercus variabilis).

Chinese cork oak (Quercus variabilis Blume) is a widespread tree species with high economic and ecological values. Chinese cork oak exhibits epicotyl dormancy, causing emergence heterogeneity and affecting the quality of seedling cultivation. Gibberellic acid-stimulated transcript (GAST) is a plant-specific protein family that plays a crucial regulatory role in plant growth, development, and seed germination. However, their evolution in Chinese cork oak and roles in epicotyl dormancy are still unclear. Here, a genome-wide identification of the GAST gene family was conducted in Chinese cork oak. Ten QvGAST genes were identified, and nine of them were expressed in seed. The physicochemical properties and promoter cis-acting elements of the selected Chinese cork oak GAST family genes indicated that the cis-acting elements in the GAST promoter are involved in plant development, hormone response, and stress response. Germinated seeds were subjected to gibberellins (GAs), abscisic acid (ABA), and fluridone treatments to show their response during epicotyl dormancy release. Significant changes in the expression of certain QvGAST genes were observed under different hormone treatments. QvGAST1, QvGAST2, QvGAST3, and QvGAST6 exhibited upregulation in response to gibberellin. QvGAST2 was markedly upregulated during the release of epicotyl dormancy in response to GA. These findings suggested that QvGAST2 might play an important role in epicotyl dormancy release. This study provides a basis for further analysis of the mechanisms underlying the alleviation of epicotyl dormancy in Chinese cork oak by QvGASTs genes.

Waist subcutaneous soft tissue metastasis of rectal mucinous adenocarcinoma: A case report.

BACKGROUND: Rectal mucinous adenocarcinoma (MAC) is a rare pathological type of rectal cancer with unique pathological features and a poor prognosis. It is difficult to diagnose and treat early because of the lack of specific manifestations in some aspects of the disease. The common metastatic organs of rectal cancer are the liver and lung; however, rectal carcinoma with metastasis to subcutaneous soft tissue is a rare finding. CASE SUMMARY: In this report, the clinical data, diagnosis and treatment process, and postoperative pathological features of a patient with left waist subcutaneous soft tissue masses were retrospectively analyzed. The patient underwent surgical treatment after admission and recovered well after surgery. The final pathological diagnosis was rectal MAC with left waist subcutaneous soft tissue metastasis. CONCLUSION: Subcutaneous soft tissue metastasis of rectal MAC is rare, and it can suggest that the tumor is disseminated, and it can appear even earlier than the primary malignant tumor, which is occult and leads to a missed diagnosis and misdiagnosis clinically. When a subcutaneous soft tissue mass of unknown origin appears in a patient with rectal cancer, a malignant tumor should be considered.

Genomic basis of the distinct biosynthesis of ß-glucogallin, a biochemical marker for hydrolyzable tannin production, in three oak species.

Hydrolyzable tannins (HTs), predominant polyphenols in oaks, are widely used in grape wine aging, feed additives, and human healthcare. However, the limited availability of a high-quality reference genome of oaks greatly hampered the recognition of the mechanism of HT biosynthesis. Here, high-quality reference genomes of three Asian oak species (Quercus variabilis, Quercus aliena, and Quercus dentata) that have different HT contents were generated. Multi-omics studies were carried out to identify key genes regulating HT biosynthesis. In vitro enzyme activity assay was also conducted. Dual-luciferase and yeast one-hybrid assays were used to reveal the transcriptional regulation. Our results revealed that ß-glucogallin was a biochemical marker for HT production in the cupules of the three Asian oaks. UGT84A13 was confirmed as the key enzyme for ß-glucogallin biosynthesis. The differential expression of UGT84A13, rather than enzyme activity, was the main reason for different ß-glucogallin and HT accumulation. Notably, sequence variations in UGT84A13 promoters led to different trans-activating activities of WRKY32/59, explaining the different expression patterns of UGT84A13 among the three species. Our findings provide three high-quality new reference genomes for oak trees and give new insights into different transcriptional regulation for understanding ß-glucogallin and HT biosynthesis in closely related oak species.

Morphology, sucrose metabolism and gene network reveal the molecular mechanism of seed fiber development in poplar.

Poplar is an important tree species for ecological protection, wood production, bioenergy and urban greening; it has been widely planted worldwide. However, the catkin fibers produced by female poplars can cause environmental pollution and safety hazards during spring. This study focused on Populus tomentosa, and revealed the sucrose metabolism regulatory mechanism of catkin fibers development from morphological, physiological and molecular aspects. Paraffin section suggested that poplar catkin fibers were not seed hairs and produced from the epidermal cells of funicle and placenta. Sucrose degradation via invertase and sucrose synthase played the dominant role during poplar catkin fibers development. The expression patterns revealed that sucrose metabolism-related genes played important roles during catkin fibers development. Y1H analysis indicated that there was a potential interaction between sucrose synthase 2 (PtoSUS2)/vacuolar invertase 3 (PtoVIN3) and trichome-regulating MYB transcription factors in poplar. Finally, the two key genes, PtoSUS2 and PtoVIN3, had roles in Arabidopsis trichome density, indicating that sucrose metabolism is important in poplar catkin fibers development. This study is not only helpful for clarifying the mechanism of sucrose regulation during trichome development in perennial woody plants, but also establishes a foundation to solve poplar catkin fibers pollution through genetic engineering methods.

Methylation detection of circulating tumor cell miR-486-5p/miR-34c-5p in the progression of colorectal cancer

Aims This study set out to examine the expression and methylation levels of miR-486-5p/miR-34c-5p and its mechanism of action based on the microRNA methylation level of circulating tumor cells (CTCs) in colorectal cancer (CRC) through clinical data and tissue detection. Methods EGFR and EpCAM immunophospholipid magnetic spheres (EpCAM-IML/EGFR-IML) were synthesized by the thin film method to capture CTCs in peripheral blood. The expression of miR-486-5p/miR-34c-5p was detected via real-time fluorescent quantitative PCR (RT-PCR). Methylation-specific PCR was implemented to detect the methylation level of miR-486-5p/miR-34c-5p, and 5-Aza-dC was used for demethylation treatment to detect the effect of changes in methylation levels on the tumor cells development. Cell Counting Kit-8 (CCK-8) analysis, transwell assay, and flow cytometry were used to determine the effects of demethylation and overexpression on the proliferation, invasion, migration, and apoptosis of CRC cells. Results The results showed that the expression and methylation levels of the miR-486-5p/miR-34c-5p isolated from CTCs were low and the methylation level was high in tumor cells and tissues. In CRC cell lines, demethylation and overexpression of miR-486-5p/miR-34c-5p could effectively inhibit the proliferation, invasion and migration of tumor cells, and facilitate tumor apoptosis (p < 0.05). Conclusion The constructed CTCs sorting system has characteristics of high specificity and high sensitivity, is a supplement to tissue samples, and has guiding significance for the clinical rational use of drugs and personalized therapy (AU)

Traits variation of acorns and cupules during maturation process in Quercus variabilis and Quercus aliena.

Quercus variabilis and Quercus aliena are two native tree species in China, which have similar habitats, and their regeneration mainly depends on acorn dispersal. This study analyzed the contents of water, soluble sugar, starch, soluble protein, and total phenolics in acorns and cupules during the whole development process to explore the difference between species. Thereinto, starch and total phenol occupied the dominant roles as their high contents. The acorn starch contents increased sharply during development in both species, but the contents in Q. variabilis were almost twice those of Q. aliena when mature. Similarly, high expression levels of starch synthase, soluble starch synthase 2 (SSS2) were also found in the acorns of Q. variabilis. The total phenol contents in Q. variabilis acorns were high at the early stages, and decreased sharply to similar contents in Q. aliena when mature. Additionally, the cupules in Q. variabilis had high contents of total phenols during the whole development period. Similar trends were also found in the expression patterns of UGT84A13 and SDH. The high total phenols in acorns and cupules of Q. variabilis probably protect the acorns from Mechoris ursulus, as only Q. aliena suffered a severe pest infestation in the early development stages. This study not only clarifies the interspecific difference between storage and defense substances during the development process in acorns and cupules, but also deepens understanding the specialized mechanisms of plant-pest/animal interactions in Quercus.

A wider spectrum of avoidance and tolerance mechanisms explained ozone sensitivity of two white poplar ploidy levels.

BACKGROUND AND AIMS: Polyploidization can improve plant mass yield for bioenergy support, yet few studies have investigated ozone (O3) sensitivity linked to internal regulatory mechanisms at different ploidy levels. METHODS: Diploid and triploid Populus tomentosa plants were exposed to ambient and ambient plus 60 ppb [O3]. We explored their differences in sensitivity (leaf morphological, physiological and biochemical traits, and plant mass) as well as mechanisms of avoidance (stomatal conductance, xanthophyll cycle, thermal dissipation) and tolerance (ROS scavenging system) in response to O3 at two developmental phases. KEY RESULTS: Triploid plants had the highest plant growth under ambient O3, even under O3 fumigation. However, triploid plants were the most sensitive to O3 and under elevated O3 showed the largest decreases in photosynthetic capacity and performance, as well as increased shoot:root ratio, and the highest lipid peroxidation. Thus, plant mass production could be impacted in triploid plants under long-term O3 contamination. Both diploid and triploid plants reduced stomatal aperture in response to O3, thereby reducing O3 entrance, yet only in diploid plants was reduced stomatal aperture associated with minimal (non-significant) damage to photosynthetic pigments and lower lipid peroxidation. CONCLUSIONS: Tolerance mechanisms of plants of both ploidy levels mainly focused on the enzymatic reduction of hydrogen peroxide through catalase and peroxidase, yet these homeostatic regulatory mechanisms were higher in diploid plants. Our study recommends triploid white poplar as a bioenergy species only under short-term O3 contamination. Under continuously elevated O3 over the long term, diploid white poplar may perform better.

The effect of topiramate versus flunarizine on the non-headache symptoms of migraine.

OBJECTIVES: To investigate the impact of topiramate versus flunarizine on the non-headache symptoms (NHS) of migraine, and to observe the changes of dopamine (DA) and prolactin (PRL) before and after prophylactic treatment. METHODS: Sixty-six episodic migraine patients were enrolled and randomized 1:1 to receive either flunarizine or topiramate treatment. Clinical characteristics and NHS associated with migraine were investigated before and after prophylactic treatment. The DA and PRL levels were also determined before and after prophylactic treatment. RESULTS: The NHS of migraine in the two groups were significantly better after treatment than before treatment in premonitory phase (PP), headache phase (HP), and resolution phase (RP). The NHS in the two groups had no significant difference in PP, HP, and RP before and after treatment. In the flunarizine group, the PRL content after treatment was significantly higher than that before treatment (t = -4.097, p < 0.001), but the DA content was decreased slightly compared with that before treatment (t = 1.909, p = 0.066). There was no significant difference in PRL content (t = 1.099, p = 0.280) and DA content (t = 1.556, p = 0.130) in topiramate group before and after treatment. CONCLUSIONS: The two classical prophylactic drugs of migraine were significantly effective in treating the NHS of migraine, but there was no significant difference between the two drugs. The DA-PRL axis may be involved in the underlying mechanism of the flunarizine treatment for the NHS of migraine.

Methylation detection of circulating tumor cell miR-486-5p/miR-34c-5p in the progression of colorectal cancer.

AIMS: This study set out to examine the expression and methylation levels of miR-486-5p/miR-34c-5p and its mechanism of action based on the microRNA methylation level of circulating tumor cells (CTCs) in colorectal cancer (CRC) through clinical data and tissue detection. METHODS: EGFR and EpCAM immunophospholipid magnetic spheres (EpCAM-IML/EGFR-IML) were synthesized by the thin film method to capture CTCs in peripheral blood. The expression of miR-486-5p/miR-34c-5p was detected via real-time fluorescent quantitative PCR (RT-PCR). Methylation-specific PCR was implemented to detect the methylation level of miR-486-5p/miR-34c-5p, and 5-Aza-dC was used for demethylation treatment to detect the effect of changes in methylation levels on the tumor cells development. Cell Counting Kit-8 (CCK-8) analysis, transwell assay, and flow cytometry were used to determine the effects of demethylation and overexpression on the proliferation, invasion, migration, and apoptosis of CRC cells. RESULTS: The results showed that the expression and methylation levels of the miR-486-5p/miR-34c-5p isolated from CTCs were low and the methylation level was high in tumor cells and tissues. In CRC cell lines, demethylation and overexpression of miR-486-5p/miR-34c-5p could effectively inhibit the proliferation, invasion and migration of tumor cells, and facilitate tumor apoptosis (p < 0.05). CONCLUSION: The constructed CTCs sorting system has characteristics of high specificity and high sensitivity, is a supplement to tissue samples, and has guiding significance for the clinical rational use of drugs and personalized therapy.

Anthocyanin Biosynthesis Associated with Natural Variation in Autumn Leaf Coloration in Quercus aliena Accessions.

Quercus aliena is an economically important tree species and one of the dominant native oak species in China. Although its leaves typically turn yellow in autumn, we observed natural variants with red leaves. It is important to understand the mechanisms involved in leaf color variation in this species. Therefore, we compared a Q. aliena tree with yellow leaves and three variants with red leaves at different stages of senescence in order to determine the causes of natural variation. We found that the accumulation of anthocyanins such as cyanidin 3-O-glucoside and cyanidin 3-O-sambubiglycoside had a significant effect on leaf coloration. Gene expression analysis showed upregulation of almost all genes encoding enzymes involved in anthocyanin synthesis in the red-leaved variants during the early and main discoloration stages of senescence. These findings are consistent with the accumulation of anthocyanin in red variants. Furthermore, the variants showed significantly higher expression of transcription factors associated with anthocyanin synthesis, such as those encoded by genes QaMYB1 and QaMYB3. Our findings provide new insights into the physiological and molecular mechanisms involved in autumn leaf coloration in Q. aliena, as well as provide genetic resources for further development and cultivation of valuable ornamental variants of this species.

Curcumin increases crizotinib sensitivity through the inactivation of autophagy via epigenetic modulation of the miR-142-5p/Ulk1 axis in non-small cell lung cancer.

Drug resistance is a critical factor responsible for the recurrence of non-small cell lung cancer (NSCLC). Previous studies suggest that curcumin acts as a chemosensitizer and radiosensitizer in human malignancies, but the underlying mechanism remains elusive. In the present study, we explored how curcumin regulates the expression of miR-142-5p and sensitizes NSCLC cells to crizotinib. We found that miR-142-5p is significantly downregulated in NSCLC tissue samples and cell lines. Curcumin could increase crizotinib cytotoxicity by epigenetically restoring the expression of miR-142-5p. Furthermore, curcumin treatment suppressed the expression of DNA methylation-related enzymes, including DNMT1, DNMT3A, and DNMT3B, in NSCLC cells. In addition, the upregulation of miR-142-5p expression increased crizotinib cytotoxicity and induced apoptosis in tumor cells in a similar manner to that of curcumin. Strikingly, miR-142-5p overexpression suppressed crizotinib-induced autophagy in A549 and H460 cells. Mechanistically, miR-142-5p inhibited autophagy in lung cancer cells by targeting Ulk1. Overexpression of Ulk1 abrogated the miR-142-5p-induced elevation of crizotinib cytotoxicity in A549 and H460 cells. Collectively, our findings demonstrate that curcumin sensitizes NSCLC cells to crizotinib by inactivating autophagy through the regulation of miR-142-5p and its target Ulk1.

Uptake of nitrogen forms by diploid and triploid white poplar depends on seasonal carbon use strategy and elevated summer ozone.

The ability of plants to acquire soil nitrogen (N) sources is plastic in response to abiotic and biotic factors. However, information about how plant preferences among N forms changes in response to internal plant N demand through growth phases, or to environmental stress such as ozone (O3), is scarce. Diploid and triploid Chinese white poplar were used to investigate N form preferences at two key developmental periods (spring, summer) and in response to summer O3 (ambient, 60 ppb above ambient). We used stable isotopes to quantify NH4+, NO3- and glycine N-uptake rates. Carbon acquisition was recorded simultaneously. Both ploidy levels differed in growth, N form preferences, and N and C use strategies. Diploid white poplars grew faster in spring but slower in summer compared with triploids. Diploid white poplars also showed plasticity among N form preferences through the season, with no preferences in spring, and NO3- preferred in summer, while triploids showed an overall preference for NO3-. Carbon acquisition and NO3- uptake were inhibited in both ploidy levels of poplar at elevated O3, which also reduced diploid total N uptake. However, triploid white poplars alleviated N uptake reduction, switching to similar preferences among N forms. We conclude that N form preferences by white poplar are driven by internal C and N use in response to nutrient demands, and external factors such as O3.

Climate and species stress resistance modulate the higher survival of large seedlings in forest restorations worldwide.

Seedling planting plays a key role in active forest restoration and regeneration of managed stands. Plant attributes at outplanting can determine tree seedling survival and consequently early success of forest plantations. Although many studies show that large seedlings of the same age within a species have higher survival than small ones, others report the opposite. This may be due to differences in environmental conditions at the planting site and in the inherent functional characteristics of species. Here, we conducted a global-scale meta-analysis to evaluate the effect of seedling size on early outplanting survival. Our meta-analysis covered 86 tree species and 142 planting locations distributed worldwide. We also assessed whether planting site aridity and key plant functional traits related to abiotic and biotic stress resistance and growth capacity, namely specific leaf area and wood density, modulate this effect. Planting large seedlings within a species consistently increases survival in forest plantations worldwide. Species' functional traits modulate the magnitude of the positive seedling size-outplanting survival relationship, showing contrasting effects due to aridity and between angiosperms and gymnosperms. For angiosperms planted in arid/semiarid sites and gymnosperms in subhumid/humid sites the magnitude of the positive effect of seedling size on survival was maximized in species with low specific leaf area and high wood density, characteristics linked to high stress resistance and slow growth. By contrast, high specific leaf area and low wood density maximized the positive effect of seedling size on survival for angiosperms planted in subhumid/humid sites. Results have key implications for implementing forest plantations globally, especially for adjusting nursery cultivation to species' functional characteristics and planting site aridity. Nursery cultivation should promote large seedlings, especially for stress sensitive angiosperms planted in humid sites and for stress-resistant species planted in dry sites.

A dose-response study in mice of a tetravalent recombinant dengue envelope domain III protein secreted from insect cells.

BACKGROUND: DENV is the most globally prevalent mosquito-transmitted virus. Induction of a broadly and potently immune response is desirable for dengue vaccine development. METHODS: Several formulations of secreted tetravalent EDIII protein containing different amounts of antigen from eukaryotic cells were used to evaluate the immune responses in mice. RESULTS: We demonstrated that the tetravalent protein induced humoral immunity against all four serotypes of DENV, even at the lowest dose assayed. Besides, cellular immunities against DENV-1 and DENV-2 were elicited by medium dose group. Importantly, the immune responses induced by the tetravalent protein were functional in clearing DENV-2 in circulation of mice. CONCLUSIONS: We believe that the tetravalent secreted EDIII protein is a potential vaccine candidate against DENV and suggest further detailed studies of this formulation in nonhuman primates.

[Preliminary Study on Detection of Circulating Tumor Cells in Lung Cancer by EGFR/Vimentin/Folic Acid Magnetic Sphere].

BACKGROUND: Circulating tumor cells (CTC) play an important role in the screening and prognosis of lung cancer, but the low efficiency and specificity of CTC isolation obviously restrict its clinical application. The purpose of this study is to explore a new and efficient isolation method of CTC in patients with non-small cell lung cancer (NSCLC) in order to achieve the purpose of early diagnosis of NSCLC. METHODS: Three kinds of immunolipid magnetic spheres of epidermal growth factor receptor (EGFR), vimentin and folic acid (FA) were prepared by thin film method. After characterization, the sorting scheme of cell line was explored, the optimal sorting scheme of NSCLC CTC was constructed, and its clinical application value was studied. RESULTS: The average capture efficiency of EGFR, Vimentin and FA magnetic spheres used alone and in combination to lung cancer cell lines was 78%, 79%, 82% and 91%, respectively. In 60 patients with lung cancer, using 2 CTC per 7.5 mL blood as cutoff value, the positive rates of EGFR, Vimentin and FA magnets used alone and in combination were 65.0%, 33.3%, 93.3% and 100%, respectively. It was also found that the number of CTC detected by combined use of the three magnetic spheres was correlated with clinical stages (P<0.05). CONCLUSIONS: The combination of three kinds of magnetic spheres can separate EGFR+, Vimentin+, FA+ expressed CTC, which is beneficial to the downstream analysis of CTC correlation. This study provides a new method to improve the efficiency of NSCLC CTC capture, and verifies that the captured CTC counting method can be used in the auxiliary diagnosis of lung cancer.

Moderate water stress does not inhibit nitrogen remobilization, allowing fast growth in high nitrogen content Quercus variabilis seedlings under dry conditions.

Remobilization of stored nitrogen (N) plays an important role in the early growth of deciduous trees in spring. Several environmental factors can modulate N remobilization, but whether water stress is one such factors is unknown. This study analyzes how the size of N storage in Quercus variabilis Blume seedlings interacts with water stress to affect N remobilization, uptake and new growth. This information is important for improving success of forest tree plantations under dry spring conditions. During the first growing season, we produced seedlings with distinct N content by applying two fall N fertilization rates (12 or 24 mg N per seedling) using 15N-enriched fertilizer. At the beginning of the second growing season, a new experiment was started where seedlings were transplanted into larger pots and subjected to two watering levels (85 or 40% of field capacity). The plants were sampled at 4 weeks (T1), 8 weeks (T2) and 12 weeks (T3) after transplanting. Low watering reduced the growth of high and low N seedlings, but high N seedlings showed greater growth than low N seedlings. During bud burst and initial shoot elongation (T1), restricted watering, which induced a moderate water stress, did not affect the amount of N remobilized from roots, the major source of stored N source at this growth stage. This suggests that high N storage can partially counteract the negative effect of moderate water stress on early growth. At T1, water stress did not affect N uptake, and high N content seedlings absorbed significantly less soil N than did low N content seedlings. At T3, in contrast, water stress was the main determinant for N uptake, with drought-stressed plants showing lower uptake than well-watered plants. We conclude that moderate drought does not inhibit N remobilization from the major storage organ at early growth stages in spring, and that increasing N storage of planted seedlings through fall fertilization can mitigate the negative effect of moderate spring drought on growth.