Nicotiana tabacum(2n=4x=48),an economically important non-food crop and a model plant for genetic studies,faces challenges in efficient genotyping of novel germplasm.To address this,we developed the Ta-LD-SC,a 20K SNP...Nicotiana tabacum(2n=4x=48),an economically important non-food crop and a model plant for genetic studies,faces challenges in efficient genotyping of novel germplasm.To address this,we developed the Ta-LD-SC,a 20K SNP Affymetrix Axiom array,based on resequencing data from 150 tobacco accessions.A total of 20,213 unique SNPs were carefully selected,achieving coverage of over 90%of the tobacco genome(Nitab4.5 and NtaSR1)with a uniform probe distribution,limiting density to no more than 5 SNPs per 200 kb.The array underwent extensive validation using 866 tobacco accessions(NP panel)and 288 F2 individuals from a cross between K326 and Oxford 26(GP panel).Performance metrics demonstrated its robustness,with high SNP call rates(93.6%-99.8%),a low technical error rate(<1%),and a superior PolyHighResolution SNP rate(79.79%)compared to other crop SNP arrays.Population structure analysis of the NP panel revealed two major introductions of foreign germplasm that have significantly influenced the genetic diversity of Chinese tobacco resources.Using the array,a genome-wide association study(GWAS)identified 62 genes linked to eight agronomic traits,and a high-density genetic map encompassing 4553 SNPs across 6606.08 cM was constructed.The Ta-LD-SC array provides a valuable tool for rapid,high-quality genotyping offering supporting marker annotations that may benefit genetic research and breeding of tobacco.展开更多
为探究节水灌溉以及品种类型对再生稻产量和稻米品质的影响,2023年在湖北蕲春和浠水开展大田试验。以3个节水抗旱稻品种(旱优8200、旱优116和旱优73)和3个优质稻品种(箴两优郢香丝苗、荃优粤农丝苗和荃优607)为供试材料,以湖北省再生稻...为探究节水灌溉以及品种类型对再生稻产量和稻米品质的影响,2023年在湖北蕲春和浠水开展大田试验。以3个节水抗旱稻品种(旱优8200、旱优116和旱优73)和3个优质稻品种(箴两优郢香丝苗、荃优粤农丝苗和荃优607)为供试材料,以湖北省再生稻大面积种植的普通水稻品种(两优6326)为对照,设置常规灌溉和节水灌溉2种水分管理方式,分析再生稻模式下不同品种产量和稻米品质对水分管理的响应差异。结果表明,相较于常规灌溉,节水灌溉处理使头季和再生季灌水量分别平均减少76%和85%,但产量和稻米的加工、外观和蒸煮食味品质在水分处理间无显著差异,且这一结果在不同试验地点间保持一致。这表明,与常规灌溉相比,节水抗旱稻和优质稻品种在节水灌溉条件下均能保持较为稳定的头季和再生季产量和稻米品质。优质稻头季和再生季产量分别为8.54 t hm^(-2)和5.88 t hm^(-2),相较于普通水稻产量差异不显著;但头季和再生季整精米率分别显著提高13.5个百分点和20.6个百分点,垩白粒率和垩白度分别显著降低22.6个百分点和6.4个百分点、10.8个百分点和1.8个百分点。节水抗旱稻在头季的产量以及稻米加工、外观和蒸煮食味品质方面与普通水稻无显著差异,但在再生季,产量显著下降17%,整精米率显著提高17.0个百分点,垩白粒率和垩白度分别降低5.5个百分点和1.0个百分点。在同一品种类型中,再生稻产量和稻米品质存在显著的品种间差异。相关性分析表明,再生季稻米的加工、外观和蒸煮食味品质指标均与头季相应指标呈正相关。因此,在降水条件较好的地区,结合优良水稻品种,实施“以雨养为主、关键生育期适时灌溉”的节水灌溉策略,可有效降低水分消耗、提升水分利用效率,同时实现再生稻的高产与优质目标。展开更多
Tobacco(Nicotiana tabacum,2n=48)is a key non-food economic crop,yet its stress response and gene regulatory mechanisms remain poorly understood.By analyzing 603 transcriptome datasets,this study identified 1405 tissue...Tobacco(Nicotiana tabacum,2n=48)is a key non-food economic crop,yet its stress response and gene regulatory mechanisms remain poorly understood.By analyzing 603 transcriptome datasets,this study identified 1405 tissue-specific genes,revealing tissue-specific synthesis of terpenoids and other ecologically important secondary metabolites in sepals and other tissues.Comparative stress-response analysis highlighted distinct gene expression patterns in leaves and roots under biotic and abiotic stresses.Additionally,28,396 expression quantitative trait loci(eQTLs)were mapped in leaves,offering valuable genetic regulatory markers.These findings provide crucial insights into tobacco’s gene expression characteristics and their functional implications,serving as a foundation for future research.展开更多
MYB-type transcription factors contain the conserved MYB DNA-binding domain of approximately 50 amino acids and are involved in the regulation of many aspects of plant growth, development, metabolism and stress respon...MYB-type transcription factors contain the conserved MYB DNA-binding domain of approximately 50 amino acids and are involved in the regulation of many aspects of plant growth, development, metabolism and stress responses. From soybean plants, we identified 156 GmMYB genes using our previously obtained 206 MYB unigenes, and 48 were found to have full-length open-reading frames. Expressions of all these identified genes were examined, and we found that expressions of 43 genes were changed upon treatment with ABA, salt, drought and/or cold stress. Three GmMYB genes, GmMYB76, GmMYB92 and GmMYB177, were chosen for further analysis. Using the yeast assay system, GmMYB76 and GmMYB92 were found to have transactivation activity and can form homodimers. GmMYB177 did not appear to have transactivation activity but can form heterodimers with GmMYB76. Yeast onehybrid assay revealed that all the three GmMYBs could bind to cis-elements TAT AAC GGT TTT TT and CCG GAA AAA AGG AT, but with different affinity, and GmMYB92 could also bind to TCT CAC CTA CC. The transgenic Arabidopsis plants overexpressing GmMYB 76 or GmMYB177 showed better performance than the GmMYB92-transgenic plants in salt and freezing tolerance. However, these transgenic plants exhibited reduced sensitivity to ABA treatment at germination stage in comparison with the wild-type plants. The three GmMYB genes differentially affected a subset of stress-responsive genes in addition to their regulation of a common subset of stress-responsive genes. These resuits indicate that the three GmMYB genes may play differential roles in stress tolerance, possibly through regulation of stress-responsive genes.展开更多
1-Deoxy-D-xylulose-5-phosphate reductoisomerase （DXR） is an important enzyme involved in the 2-C-methyi-D- erythritol-4-phosphate （MEP） pathway which provides the basic five-carbon units for isoprenoid biosynthesi...1-Deoxy-D-xylulose-5-phosphate reductoisomerase （DXR） is an important enzyme involved in the 2-C-methyi-D- erythritol-4-phosphate （MEP） pathway which provides the basic five-carbon units for isoprenoid biosynthesis. To investigate the role of the MEP pathway in plant development and metabolism, we carried out detailed analyses on a dxr mutant （GK_215C01） and two DXR transgenic co-suppression fines, OX-DXR-L2 and OX-DXR-L7. We found that the dxr mutant was albino and dwarf. It never bolted, had significantly reduced number of trichomes and most of the stomata could not close normally in the leaves. The two co-suppression lines produced more yellow inflorescences and albino sepals with no trichomes. The transcription levels of genes involved in tricbome initiation were found to be strongly affected, including GLABRA1, TRANSPARENT TESTA GLABROUS 1, TRIPTYCHON and SPINDLY, expression of which is regulated by gibberellic acids （GAs）. Exogenous application of GA3 could partially rescue the dwarf phenotype and the trichome initiation of dxr, whereas exogenous application of abscisic acid （ABA） could rescue the stomata closure defect, suggesting that lower levels of both GA and ABA contribute to the phenotype in the dxr mutants. We further found that genes involved in the biosynthetic pathways of GA and ABA were coordinately regulated. These results indicate that disruption of the plastidial MEP pathway leads to biosynthetic deficiency of photosynthetic pigments, GAs and ABA, and thus the developmental abnormalities, and that the flux from the cytoplasmic mevalonate pathway is not sufficient to rescue the deficiency caused by the blockage of the plastidial MEP pathway. These results reveal a critical role for the MEP biosynthetic pathway in controlling the biosynthesis of isoprenoids.展开更多
Plasma membrane intrinsic proteins （PIPs） are a subfamily ofaquaporins that enable fast and controlled translocation of water across the membrane. In this study, we systematically identified and cloned ten PIP genes...Plasma membrane intrinsic proteins （PIPs） are a subfamily ofaquaporins that enable fast and controlled translocation of water across the membrane. In this study, we systematically identified and cloned ten PIP genes from rice. Based on the similarity of the amino acid sequences they encoded, these rice PIP genes were classified into two groups and designated as OsPIP1-1 to OsPIP1-3 and OsPIP2-1 to OsPIP2-7 following the nomenclature of PIP genes in maize. Quantitative RT-PCR analysis identified three root-specific and one leaf-specific OsPIP genes. Furthermore, the expression profile of each OsPIP gene in response to salt, drought and ABA treatment was examined in detail. Analysis on transgenic plants over-expressing of either OsPIP1 （OsPIP1-1） or OsPIP2 （OsPIP2-2） in wild-type Arabidopsis, showed enhanced tolerance to salt （100 mM of NaCl） and drought （200 mM ofmannitol）, but not to salt treatment of higher concentration （150 mM of NaCl）. Taken together, these data suggest a distinct role of each OsPIP gene in response to different stresses, and should add a new layer to the understanding of the physiological function of rice PIP genes.展开更多
Cytokinin is a critical growth regulator for various aspects of plant growth and development. In Arabidopsis, cytokinin signaling is mediated by a two-component system-based phosphorelay that transmits a signal from t...Cytokinin is a critical growth regulator for various aspects of plant growth and development. In Arabidopsis, cytokinin signaling is mediated by a two-component system-based phosphorelay that transmits a signal from the receptors, through histidine phosphotransfer proteins, to the downstream response regulators （ARRs）. Of these ARRs, type-A ARR genes, whose transcription can be rapidly induced by cytokinin, act as negative regulators of eytokinin signaling. However, because of functional redundancy, the function of type-A ARR genes in plant growth and development is not well understood by analyzing loss-of-function mutants. In this study, we performed a comparative functional study on all ten type-A ARR genes by analyzing transgenic plants overexpressing these ARR genes fused to a MYC epitope tag. Overexpression of ARR genes results in a variety of cytokinin-associated phenotypes. Notably, overexpression of different ARR transgenes causes diverse phenotypes, even between phylogenetically closely-related gene pairs, such as within the ARR3-ARR4 and ARR5-ARR6 pairs. We found that the accumulation of a subset of ARR proteins （ARR3, ARR5, ARR7, ARR16 and ARR17; possibly ARR8 and ARR15） is increased by MG132, a specific proteasomal inhibitor, indicating that stability of these proteins is regulated by proteasomal degradation. Moreover, similar to that of previously characterized ARR5, ARR6 and ARR7, stability of ARR16 and ARR17, possibly including ARR8 and ARR15, is regulated by cytokinin. These results suggest that type-A ARR proteins are regulated by a combinatorial mechanism involving both the cytokinin and proteasome pathways, thereby executing distinctive functions in plant growth and development.展开更多
To further improve upland rice varieties Huhan 3 and Huhan 7, seed samples were sent to outer space with two recoverable spaceships for approximately 1 and 5 d and were propagated for 7 and 5 generations, respectively...To further improve upland rice varieties Huhan 3 and Huhan 7, seed samples were sent to outer space with two recoverable spaceships for approximately 1 and 5 d and were propagated for 7 and 5 generations, respectively. Phenotypic analysis revealed that the morphological traits and the protein and amylose contents of grains changed. Characterization of genomic mutations by the gene-associated simple sequence repeat （SSR） and insertion-delete （InDel） markers indicated that the mutation pattern was very complex. Most of the mutations occurred at the 3＇- or 5＇-end of the fragments in the simple sequence repeat fragment. Reverse transcription-polymerase chain reaction （RT-PCR） assay showed that mutations in those parts of the SSR affected their gene expression, indicating that gene associated markers would be helpful to isolate functional genes. Field survey for breeding also revealed that more lines with high yield, high quality and drought-tolerance could be selected through aerospace breeding. The results indicate that aerospace mutagenesis resulted in molecular variation, as well as physiological and morphological changes for rice breeding.展开更多
Metabolism of S-nitrosoglutathione （GSNO）, a major biologically active nitric oxide （NO） species, is catalyzed by the evolutionally conserved GSNO reductase （GSNOR）. Previous studies showed that the Arabidopsis ...Metabolism of S-nitrosoglutathione （GSNO）, a major biologically active nitric oxide （NO） species, is catalyzed by the evolutionally conserved GSNO reductase （GSNOR）. Previous studies showed that the Arabidopsis GSNOR1/ HOT5 gene regulates salicylic acid signaling and thermotolerance by modulating the intracellular S-nitrosothiol level. Here, we report the characterization of the Arabidopsisparaquat resistant2-1 （par2-1） mutant that shows an anti-cell death phenotype. The production of superoxide in par2-1 is comparable to that of wild-type plants when treated by paraquat （1,1＇-dimethyl-4,4＇-bipyridinium dichloride）, suggesting that PAR2 acts downstream of superoxide to regulate cell death. PAR2, identified by positional cloning, is shown to be identical to GSNOR1/HOT5. The par2-1 mutant carries a missense mutation in a highly conserved glycine, which renders the mutant protein unstable. Compared to wild type, par2-1 mutant has a higher NO level, as revealed by staining with 4,5-diaminofluorescein diacetate. Consistent with this result, wild-type plants treated with an NO donor display resistance to paraquat. Interestingly, the GSNOR1/HOT5/PAR2 protein level, other than its steady-state mRNA level, is induced by paraquat, but is reduced by NO donors. Taken together, these results suggest that GSNOR1/HOT5/PAR2 plays an important role in regulating cell death in plant cells through modulating intracellular NO level.展开更多
MYB proteins play important roles in eukaryotic organisms. In plants, the R1R2R3-type MYB proteins function in cell cycle control. However, whether the R2R3-type MYB protein is also involved in the cell division proce...MYB proteins play important roles in eukaryotic organisms. In plants, the R1R2R3-type MYB proteins function in cell cycle control. However, whether the R2R3-type MYB protein is also involved in the cell division process remains unknown. Here, we report that an R2R3-type transcription factor gene, AtMYB59, is involved in the regulation of cell cycle progression and root growth. The AtMYB59 protein is localized in the nuclei of onion epidermal cells and has transactivation activity. Expression of AtMYB59 in yeast cells suppresses cell proliferation, and the transfor- mants have more nuclei and higher anenpioid DNA content with longer cells. Mutation in the conserved domain of AtMYB59 abolishes its effects on yeast cell growth. In synchronized Arabidopsis cell suspensions, the AtMYB59 gene is specifically expressed in the S phase during cell cycle progression. Expression and promoter-GUS analysis reveals that the AtMYB59 gene is abundantly expressed in roots. Transgenic plants overexpressing AtMYB59 have shorter roots compared with wild-type plants （Arabidopsis accession Col-0）, and around half of the mitotic cells in root tips are at metaphase. Conversely, the null mutant myb59-1 has longer roots and fewer mitotic cells at metaphase than Col, suggesting that AtMYB59 may inhibit root growth by extending the metaphase of mitotic cells. AtMYB59 regulates many downstream genes, including the CYCB1;1 gene, probably through binding to MYB-responsive elements. These results support a role forAtMYB59 in cell cycle regulation and plant root growth.展开更多
The field of gene therapy has been increasingly studied in the last four decades, and its clinical application has become a reality in the last 15 years. Traditional Chinese medicine （TCM）, an important component of...The field of gene therapy has been increasingly studied in the last four decades, and its clinical application has become a reality in the last 15 years. Traditional Chinese medicine （TCM）, an important component of complementary and alternative medicine, has evolved over thousands of years with its own unique system of theories, diagnostics and therapies. TCM is well-known for its various roles in preventing and treating infectious and chronic diseases, and its usage in other modern clinical practice. However, whether TCM can be applied alongside gene therapy is a topic that has not been systematically examined. Here we provide an overview of TCM theories in relation to gene therapy. We believe that TCM theories are congruent with some principles of gene therapy. TCM-derived drugs may also act as gene therapy vehicles, therapeutic genes, synergistic therapeutic treatments, and as co-administrated drugs to reduce side effects. We also discuss in this review some possible approaches to combine TCM and gene therapy.展开更多
Carotenoids play an important role in many physiological processes in plants and the phytoene desaturase gene （PDS3） encodes one of the important enzymes in the carotenoid biosynthesis pathway. Here we report the id...Carotenoids play an important role in many physiological processes in plants and the phytoene desaturase gene （PDS3） encodes one of the important enzymes in the carotenoid biosynthesis pathway. Here we report the identification and analysis of a T-DNA insertion mutant of PDS3 gene. Functional complementation confirmed that both the albino and dwarfphenotypes ofthepds3 mutant resulted from functional disruption of the PDS3 gene. Chloroplast development was arrested at the proplastid stage in thepds3 mutant. Further analysis showed that high level ofphytoene was accumulated in the pds3 mutant. Addition of exogenous GA3 could partially rescue the dwarf phenotype, suggesting that the dwarf phenotype ofthepds3 mutant might be due to GA deficiency. Microarray and RT-PCR analysis showed that disrupting PDS3 gene resulted in gene expression changes involved in at least 20 metabolic pathways, including the inhibition of many genes in carotenoid, chlorophyll, and GA biosynthesis pathways. Our data suggest that the accumulated phytoene in the pds3 mutant might play an important role in certain negative feedbacks to affect gene expression of diverse cellular pathways.展开更多
Carotenoids, a class of natural pigments found in all photosynthetic organisms, are involved in a variety of physiological processes, including coloration, photoprotection, biosynthesis of abscisic acid （ABA） and ch...Carotenoids, a class of natural pigments found in all photosynthetic organisms, are involved in a variety of physiological processes, including coloration, photoprotection, biosynthesis of abscisic acid （ABA） and chloroplast biogenesis. Although carotenoid biosynthesis has been well studied biochemically, the genetic basis of the pathway is not well understood. Here, we report the characterization of two allelic Arabidopsis mutants, spontaneous cell death1-1 （spcl-1） and spc1-2. The weak allele spc1-1 mutant showed characteristics of bleached leaves, accumulation of superoxide and mosaic cell death. The strong mutant allele spc1-2 caused a complete arrest of plant growth and development shortly after germination, leading to a seedling-lethal phenotype. Genetic and molecular analyses indicated that SPC1 encodes a putative ζ-carotene desaturase （ZDS） in the carotenoid biosynthesis pathway. Analysis of carotenoids revealed that several major carotenoid compounds downstream of SPC 1/ZDS were substantially reduced in spc1-1, suggesting that SPC 1 is a functional ZDS. Consistent with the downregulated expression of CAO and PORB, the chlorophyll content was decreased in spc1-1 plants. In addition, expression of Lhcb1. 1, Lhcbl. 4 and RbcS was absent in spc1-2, suggesting the possible involvement of carotenoids in the plastid-to-nucleus retrograde signaling. The spc1-1 mutant also displays an ABA-deficient phenotype that can be partially rescued by the externally supplied phytohormone. These results suggest that SPC1/ZDS is essential for biosynthesis of carotenoids and plays a crucial role in plant growth and development.展开更多
Deep rooting is an important trait in rice drought resistance.Genetic resources of deep-rooting varieties are valuable in breeding of water-saving and drought-resistant rice.In the present study,234BC2F7 backcross int...Deep rooting is an important trait in rice drought resistance.Genetic resources of deep-rooting varieties are valuable in breeding of water-saving and drought-resistant rice.In the present study,234BC2F7 backcross introgression lines were derived from a cross of Dongye 80(an accession of Dongxiang wild rice as the donor parent)and R974(an indica restorer line as the recurrent parent).A genetic linkage map containing 1977 bin markers was constructed by ddRADSeq for QTL analysis.Thirty-one QTLs for four root traits(the number of deep roots,the number of shallow roots,the total number of deep roots and the ratio of deep roots)were assessed on six rice chromosomes in two environments(2020 Shanghai and 2021 Hainan).Two of the QTLs,qDR5.1 and qTR5.2,were located on chromosome 5 in a 70-kb interval.They were detected in both environments.qDR5.1 explained 13.35%of the phenotypic variance in 2020 Shanghai and 12.01%of the phenotypic variance in 2021 Hainan.qTR5.2 accounted for 10.88%and 10.93%of the phenotypic variance,respectively.One QTL(qRDR2.2)for the ratio of deep roots was detected on chromosome 2 in a 210-kb interval and accounted for 6.72%of the phenotypic variance in 2020.The positive effects of these three QTLs were all from Dongxiang wild rice.Furthermore,nine and four putative candidate genes were identified in qRDR2.2 and qDR5.1/qTR5.2,respectively.These findings added to our knowledge of the genetic control of root traits in rice.In addition,this study will facilitate the future isolation of candidate genes of the deep-rooting trait and the utilization of Dongxiang wild rice in the improvement of rice drought resistance.展开更多
Complex I （the NADH：ubiquinone oxidoreductase） of the mitochondrial respiratory chain is a complicated, multi-subunit, membrane- bound assembly and contains more than 40 different proteins in higher plants. In this...Complex I （the NADH：ubiquinone oxidoreductase） of the mitochondrial respiratory chain is a complicated, multi-subunit, membrane- bound assembly and contains more than 40 different proteins in higher plants. In this paper, we characterize the Arabidopsis homologue （designated as AtCIB22） of the B22 subunit of eukaryotic mitochondriai Complex I. AtCIB22 is a single-copy gene and is highly con- served throughout eukaryotes. AtCIB22 protein is located in mitochondria and the AtC1B22 gene is widely expressed in different tissues. Mutant Arabidopsis plants with a disrupted AtC1B22 gene display pleiotropic phenotypes including shorter roots, smaller plants and de- layed flowering. Stress analysis indicates that the AtC1B22 mutants＇ seed germination and early seedling growth are severely inhibited by sucrose deprivation stress but more tolerant to ethanol stress. Molecular analysis reveals that in moderate knockdown AtCIB22 mutants, genes including cell redox proteins and stress related proteins are significantly up-regulated, and that in severe knockdown AtCIB22 mu- tants, the alternative respiratory pathways including NDA1, NDB2, AOXla and AtPUMP1 are remarkably elevated. These data demon- strate that AtCIB22 is essential for plant development and mitochondrial electron transport chains in Arabidopsis. Our findings also en- hance our understanding about the physiological role of Complex I in plants.展开更多
P-450-dependent epoxygenase pathway of arachidonic acid and the products of epoxyeicosatrienoic acids（EETs） have been demonstrated to be involved in angiogenesis and tumor progression.This study examined the express...P-450-dependent epoxygenase pathway of arachidonic acid and the products of epoxyeicosatrienoic acids（EETs） have been demonstrated to be involved in angiogenesis and tumor progression.This study examined the expression of EETs and the role of the pathway in the angiogenesis of multiple myeloma（MM）.MM cell lines of U266 and RPMI8226 were cultured,and the EETs levels（11,12-EET and 14,15-EET） in the supernatant were determined by ELISA.Human umbilical vein endothelial cells（HUVECs） were cultured and used for analysis of the angiogenesis activity of the two MM cell lines,which was examined both in vitro and in vivo by employing MTT,chemotaxis,tube formation and matrigel plug assays.11,12-EET and 14,15-EET were found in the supernatant of the cultured MM cells.The levels of the two EETs in the supernatant of U266 cells were significantly higher than those in the RPMI8226 cell supernatant（P〈0.05）,and the levels paralleled the respective angiogenesis activity of the two different MM cell lines.17-octadecynoic acid（17-ODYA）,as a specific inhibitor of P450 enzyme,suppressed HUVECs proliferation and tube formation induced by MM cells.Furthermore,17-ODYA decreased the EET levels in the supernatant of MM cells.These results suggest that EETs may play an important role in the angiogenesis of MM,and the inhibitor 17-ODYA suppresses this effect.展开更多
基金supported by the Guizhou Provincial Basic Research Program(Natural Science)[(2024)648]the Program of China National Tobacco Corporation(110202101032(JY-09),110202201003(JY-03))the Program of Guizhou Branch of China National Tobacco Corporation(2023XM02,2021XM05,2022XM05,2024XM01).
文摘Nicotiana tabacum(2n=4x=48),an economically important non-food crop and a model plant for genetic studies,faces challenges in efficient genotyping of novel germplasm.To address this,we developed the Ta-LD-SC,a 20K SNP Affymetrix Axiom array,based on resequencing data from 150 tobacco accessions.A total of 20,213 unique SNPs were carefully selected,achieving coverage of over 90%of the tobacco genome(Nitab4.5 and NtaSR1)with a uniform probe distribution,limiting density to no more than 5 SNPs per 200 kb.The array underwent extensive validation using 866 tobacco accessions(NP panel)and 288 F2 individuals from a cross between K326 and Oxford 26(GP panel).Performance metrics demonstrated its robustness,with high SNP call rates(93.6%-99.8%),a low technical error rate(<1%),and a superior PolyHighResolution SNP rate(79.79%)compared to other crop SNP arrays.Population structure analysis of the NP panel revealed two major introductions of foreign germplasm that have significantly influenced the genetic diversity of Chinese tobacco resources.Using the array,a genome-wide association study(GWAS)identified 62 genes linked to eight agronomic traits,and a high-density genetic map encompassing 4553 SNPs across 6606.08 cM was constructed.The Ta-LD-SC array provides a valuable tool for rapid,high-quality genotyping offering supporting marker annotations that may benefit genetic research and breeding of tobacco.
文摘为探究节水灌溉以及品种类型对再生稻产量和稻米品质的影响,2023年在湖北蕲春和浠水开展大田试验。以3个节水抗旱稻品种(旱优8200、旱优116和旱优73)和3个优质稻品种(箴两优郢香丝苗、荃优粤农丝苗和荃优607)为供试材料,以湖北省再生稻大面积种植的普通水稻品种(两优6326)为对照,设置常规灌溉和节水灌溉2种水分管理方式,分析再生稻模式下不同品种产量和稻米品质对水分管理的响应差异。结果表明,相较于常规灌溉,节水灌溉处理使头季和再生季灌水量分别平均减少76%和85%,但产量和稻米的加工、外观和蒸煮食味品质在水分处理间无显著差异,且这一结果在不同试验地点间保持一致。这表明,与常规灌溉相比,节水抗旱稻和优质稻品种在节水灌溉条件下均能保持较为稳定的头季和再生季产量和稻米品质。优质稻头季和再生季产量分别为8.54 t hm^(-2)和5.88 t hm^(-2),相较于普通水稻产量差异不显著;但头季和再生季整精米率分别显著提高13.5个百分点和20.6个百分点,垩白粒率和垩白度分别显著降低22.6个百分点和6.4个百分点、10.8个百分点和1.8个百分点。节水抗旱稻在头季的产量以及稻米加工、外观和蒸煮食味品质方面与普通水稻无显著差异,但在再生季,产量显著下降17%,整精米率显著提高17.0个百分点,垩白粒率和垩白度分别降低5.5个百分点和1.0个百分点。在同一品种类型中,再生稻产量和稻米品质存在显著的品种间差异。相关性分析表明,再生季稻米的加工、外观和蒸煮食味品质指标均与头季相应指标呈正相关。因此,在降水条件较好的地区,结合优良水稻品种,实施“以雨养为主、关键生育期适时灌溉”的节水灌溉策略,可有效降低水分消耗、提升水分利用效率,同时实现再生稻的高产与优质目标。
基金supported by the Guizhou Provincial Basic Research Program(Natural Science)[(2024)648]the Program of China National Tobacco Corporation(110202101032(JY-09),110202201003(JY-03))+2 种基金the Program of Guizhou Branch of China National Tobacco Corporation(2023XM02,2022XM05 and 2024XM01)the Qiankehe Platform Project(ZSYS[2025]028)the Program of China National Tobacco Corporation(110202102034).
文摘Tobacco(Nicotiana tabacum,2n=48)is a key non-food economic crop,yet its stress response and gene regulatory mechanisms remain poorly understood.By analyzing 603 transcriptome datasets,this study identified 1405 tissue-specific genes,revealing tissue-specific synthesis of terpenoids and other ecologically important secondary metabolites in sepals and other tissues.Comparative stress-response analysis highlighted distinct gene expression patterns in leaves and roots under biotic and abiotic stresses.Additionally,28,396 expression quantitative trait loci(eQTLs)were mapped in leaves,offering valuable genetic regulatory markers.These findings provide crucial insights into tobacco’s gene expression characteristics and their functional implications,serving as a foundation for future research.
基金Acknowledgments This work was supported by the National Natural Science Foundation of China （30490254, 30671316）, the National Basic Research Program of China （2006CB100102）, and the Hi-Tech Research and Development Program of China （2006AA10Z113, 2006AA10A111）.
文摘MYB-type transcription factors contain the conserved MYB DNA-binding domain of approximately 50 amino acids and are involved in the regulation of many aspects of plant growth, development, metabolism and stress responses. From soybean plants, we identified 156 GmMYB genes using our previously obtained 206 MYB unigenes, and 48 were found to have full-length open-reading frames. Expressions of all these identified genes were examined, and we found that expressions of 43 genes were changed upon treatment with ABA, salt, drought and/or cold stress. Three GmMYB genes, GmMYB76, GmMYB92 and GmMYB177, were chosen for further analysis. Using the yeast assay system, GmMYB76 and GmMYB92 were found to have transactivation activity and can form homodimers. GmMYB177 did not appear to have transactivation activity but can form heterodimers with GmMYB76. Yeast onehybrid assay revealed that all the three GmMYBs could bind to cis-elements TAT AAC GGT TTT TT and CCG GAA AAA AGG AT, but with different affinity, and GmMYB92 could also bind to TCT CAC CTA CC. The transgenic Arabidopsis plants overexpressing GmMYB 76 or GmMYB177 showed better performance than the GmMYB92-transgenic plants in salt and freezing tolerance. However, these transgenic plants exhibited reduced sensitivity to ABA treatment at germination stage in comparison with the wild-type plants. The three GmMYB genes differentially affected a subset of stress-responsive genes in addition to their regulation of a common subset of stress-responsive genes. These resuits indicate that the three GmMYB genes may play differential roles in stress tolerance, possibly through regulation of stress-responsive genes.
基金Acknowledgments This work was supported by the National Natural Science Foundation of China （NSFC Grant 90717003 to L-J Qu）.
文摘1-Deoxy-D-xylulose-5-phosphate reductoisomerase （DXR） is an important enzyme involved in the 2-C-methyi-D- erythritol-4-phosphate （MEP） pathway which provides the basic five-carbon units for isoprenoid biosynthesis. To investigate the role of the MEP pathway in plant development and metabolism, we carried out detailed analyses on a dxr mutant （GK_215C01） and two DXR transgenic co-suppression fines, OX-DXR-L2 and OX-DXR-L7. We found that the dxr mutant was albino and dwarf. It never bolted, had significantly reduced number of trichomes and most of the stomata could not close normally in the leaves. The two co-suppression lines produced more yellow inflorescences and albino sepals with no trichomes. The transcription levels of genes involved in tricbome initiation were found to be strongly affected, including GLABRA1, TRANSPARENT TESTA GLABROUS 1, TRIPTYCHON and SPINDLY, expression of which is regulated by gibberellic acids （GAs）. Exogenous application of GA3 could partially rescue the dwarf phenotype and the trichome initiation of dxr, whereas exogenous application of abscisic acid （ABA） could rescue the stomata closure defect, suggesting that lower levels of both GA and ABA contribute to the phenotype in the dxr mutants. We further found that genes involved in the biosynthetic pathways of GA and ABA were coordinately regulated. These results indicate that disruption of the plastidial MEP pathway leads to biosynthetic deficiency of photosynthetic pigments, GAs and ABA, and thus the developmental abnormalities, and that the flux from the cytoplasmic mevalonate pathway is not sufficient to rescue the deficiency caused by the blockage of the plastidial MEP pathway. These results reveal a critical role for the MEP biosynthetic pathway in controlling the biosynthesis of isoprenoids.
文摘Plasma membrane intrinsic proteins （PIPs） are a subfamily ofaquaporins that enable fast and controlled translocation of water across the membrane. In this study, we systematically identified and cloned ten PIP genes from rice. Based on the similarity of the amino acid sequences they encoded, these rice PIP genes were classified into two groups and designated as OsPIP1-1 to OsPIP1-3 and OsPIP2-1 to OsPIP2-7 following the nomenclature of PIP genes in maize. Quantitative RT-PCR analysis identified three root-specific and one leaf-specific OsPIP genes. Furthermore, the expression profile of each OsPIP gene in response to salt, drought and ABA treatment was examined in detail. Analysis on transgenic plants over-expressing of either OsPIP1 （OsPIP1-1） or OsPIP2 （OsPIP2-2） in wild-type Arabidopsis, showed enhanced tolerance to salt （100 mM of NaCl） and drought （200 mM ofmannitol）, but not to salt treatment of higher concentration （150 mM of NaCl）. Taken together, these data suggest a distinct role of each OsPIP gene in response to different stresses, and should add a new layer to the understanding of the physiological function of rice PIP genes.
文摘Cytokinin is a critical growth regulator for various aspects of plant growth and development. In Arabidopsis, cytokinin signaling is mediated by a two-component system-based phosphorelay that transmits a signal from the receptors, through histidine phosphotransfer proteins, to the downstream response regulators （ARRs）. Of these ARRs, type-A ARR genes, whose transcription can be rapidly induced by cytokinin, act as negative regulators of eytokinin signaling. However, because of functional redundancy, the function of type-A ARR genes in plant growth and development is not well understood by analyzing loss-of-function mutants. In this study, we performed a comparative functional study on all ten type-A ARR genes by analyzing transgenic plants overexpressing these ARR genes fused to a MYC epitope tag. Overexpression of ARR genes results in a variety of cytokinin-associated phenotypes. Notably, overexpression of different ARR transgenes causes diverse phenotypes, even between phylogenetically closely-related gene pairs, such as within the ARR3-ARR4 and ARR5-ARR6 pairs. We found that the accumulation of a subset of ARR proteins （ARR3, ARR5, ARR7, ARR16 and ARR17; possibly ARR8 and ARR15） is increased by MG132, a specific proteasomal inhibitor, indicating that stability of these proteins is regulated by proteasomal degradation. Moreover, similar to that of previously characterized ARR5, ARR6 and ARR7, stability of ARR16 and ARR17, possibly including ARR8 and ARR15, is regulated by cytokinin. These results suggest that type-A ARR proteins are regulated by a combinatorial mechanism involving both the cytokinin and proteasome pathways, thereby executing distinctive functions in plant growth and development.
基金supported by the National High-Technology Research and Development Program of China(Grant No.2010AA101805)National Key Technology R&D Program of China(Grant No.2013ZX08001-003)Shanghai Agricultural Science and Technology Key Projects,China(Grant No.2009-6-4-2)
文摘To further improve upland rice varieties Huhan 3 and Huhan 7, seed samples were sent to outer space with two recoverable spaceships for approximately 1 and 5 d and were propagated for 7 and 5 generations, respectively. Phenotypic analysis revealed that the morphological traits and the protein and amylose contents of grains changed. Characterization of genomic mutations by the gene-associated simple sequence repeat （SSR） and insertion-delete （InDel） markers indicated that the mutation pattern was very complex. Most of the mutations occurred at the 3＇- or 5＇-end of the fragments in the simple sequence repeat fragment. Reverse transcription-polymerase chain reaction （RT-PCR） assay showed that mutations in those parts of the SSR affected their gene expression, indicating that gene associated markers would be helpful to isolate functional genes. Field survey for breeding also revealed that more lines with high yield, high quality and drought-tolerance could be selected through aerospace breeding. The results indicate that aerospace mutagenesis resulted in molecular variation, as well as physiological and morphological changes for rice breeding.
基金We thank Dr Gary Loake （University of Edinburgh, UK） for providing gsnor1-3 seeds. We are grateful to Drs Chuanyou Li, Shuhua Yang and Yiqin Wang for critically reading the manuscript. This study was supported by grants from the National Natural Science Foundation of China （30330360）, the Ministry of Science and Technology of China （2006AA 10A 112） and the Chinese Academy of Sciences （KSCX2-YW-N-015）.
文摘Metabolism of S-nitrosoglutathione （GSNO）, a major biologically active nitric oxide （NO） species, is catalyzed by the evolutionally conserved GSNO reductase （GSNOR）. Previous studies showed that the Arabidopsis GSNOR1/ HOT5 gene regulates salicylic acid signaling and thermotolerance by modulating the intracellular S-nitrosothiol level. Here, we report the characterization of the Arabidopsisparaquat resistant2-1 （par2-1） mutant that shows an anti-cell death phenotype. The production of superoxide in par2-1 is comparable to that of wild-type plants when treated by paraquat （1,1＇-dimethyl-4,4＇-bipyridinium dichloride）, suggesting that PAR2 acts downstream of superoxide to regulate cell death. PAR2, identified by positional cloning, is shown to be identical to GSNOR1/HOT5. The par2-1 mutant carries a missense mutation in a highly conserved glycine, which renders the mutant protein unstable. Compared to wild type, par2-1 mutant has a higher NO level, as revealed by staining with 4,5-diaminofluorescein diacetate. Consistent with this result, wild-type plants treated with an NO donor display resistance to paraquat. Interestingly, the GSNOR1/HOT5/PAR2 protein level, other than its steady-state mRNA level, is induced by paraquat, but is reduced by NO donors. Taken together, these results suggest that GSNOR1/HOT5/PAR2 plays an important role in regulating cell death in plant cells through modulating intracellular NO level.
文摘MYB proteins play important roles in eukaryotic organisms. In plants, the R1R2R3-type MYB proteins function in cell cycle control. However, whether the R2R3-type MYB protein is also involved in the cell division process remains unknown. Here, we report that an R2R3-type transcription factor gene, AtMYB59, is involved in the regulation of cell cycle progression and root growth. The AtMYB59 protein is localized in the nuclei of onion epidermal cells and has transactivation activity. Expression of AtMYB59 in yeast cells suppresses cell proliferation, and the transfor- mants have more nuclei and higher anenpioid DNA content with longer cells. Mutation in the conserved domain of AtMYB59 abolishes its effects on yeast cell growth. In synchronized Arabidopsis cell suspensions, the AtMYB59 gene is specifically expressed in the S phase during cell cycle progression. Expression and promoter-GUS analysis reveals that the AtMYB59 gene is abundantly expressed in roots. Transgenic plants overexpressing AtMYB59 have shorter roots compared with wild-type plants （Arabidopsis accession Col-0）, and around half of the mitotic cells in root tips are at metaphase. Conversely, the null mutant myb59-1 has longer roots and fewer mitotic cells at metaphase than Col, suggesting that AtMYB59 may inhibit root growth by extending the metaphase of mitotic cells. AtMYB59 regulates many downstream genes, including the CYCB1;1 gene, probably through binding to MYB-responsive elements. These results support a role forAtMYB59 in cell cycle regulation and plant root growth.
文摘The field of gene therapy has been increasingly studied in the last four decades, and its clinical application has become a reality in the last 15 years. Traditional Chinese medicine （TCM）, an important component of complementary and alternative medicine, has evolved over thousands of years with its own unique system of theories, diagnostics and therapies. TCM is well-known for its various roles in preventing and treating infectious and chronic diseases, and its usage in other modern clinical practice. However, whether TCM can be applied alongside gene therapy is a topic that has not been systematically examined. Here we provide an overview of TCM theories in relation to gene therapy. We believe that TCM theories are congruent with some principles of gene therapy. TCM-derived drugs may also act as gene therapy vehicles, therapeutic genes, synergistic therapeutic treatments, and as co-administrated drugs to reduce side effects. We also discuss in this review some possible approaches to combine TCM and gene therapy.
基金the National Natural Science Foundation of China （Grant No. 30470172）.
文摘Carotenoids play an important role in many physiological processes in plants and the phytoene desaturase gene （PDS3） encodes one of the important enzymes in the carotenoid biosynthesis pathway. Here we report the identification and analysis of a T-DNA insertion mutant of PDS3 gene. Functional complementation confirmed that both the albino and dwarfphenotypes ofthepds3 mutant resulted from functional disruption of the PDS3 gene. Chloroplast development was arrested at the proplastid stage in thepds3 mutant. Further analysis showed that high level ofphytoene was accumulated in the pds3 mutant. Addition of exogenous GA3 could partially rescue the dwarf phenotype, suggesting that the dwarf phenotype ofthepds3 mutant might be due to GA deficiency. Microarray and RT-PCR analysis showed that disrupting PDS3 gene resulted in gene expression changes involved in at least 20 metabolic pathways, including the inhibition of many genes in carotenoid, chlorophyll, and GA biosynthesis pathways. Our data suggest that the accumulated phytoene in the pds3 mutant might play an important role in certain negative feedbacks to affect gene expression of diverse cellular pathways.
基金grants from National Natural Science Foundation of China （Grant Nos. 30330360, 30125025 , 30221002） Chinese Academy of Sciences （Grant No. KSCX2- YW-N-015）
文摘Carotenoids, a class of natural pigments found in all photosynthetic organisms, are involved in a variety of physiological processes, including coloration, photoprotection, biosynthesis of abscisic acid （ABA） and chloroplast biogenesis. Although carotenoid biosynthesis has been well studied biochemically, the genetic basis of the pathway is not well understood. Here, we report the characterization of two allelic Arabidopsis mutants, spontaneous cell death1-1 （spcl-1） and spc1-2. The weak allele spc1-1 mutant showed characteristics of bleached leaves, accumulation of superoxide and mosaic cell death. The strong mutant allele spc1-2 caused a complete arrest of plant growth and development shortly after germination, leading to a seedling-lethal phenotype. Genetic and molecular analyses indicated that SPC1 encodes a putative ζ-carotene desaturase （ZDS） in the carotenoid biosynthesis pathway. Analysis of carotenoids revealed that several major carotenoid compounds downstream of SPC 1/ZDS were substantially reduced in spc1-1, suggesting that SPC 1 is a functional ZDS. Consistent with the downregulated expression of CAO and PORB, the chlorophyll content was decreased in spc1-1 plants. In addition, expression of Lhcb1. 1, Lhcbl. 4 and RbcS was absent in spc1-2, suggesting the possible involvement of carotenoids in the plastid-to-nucleus retrograde signaling. The spc1-1 mutant also displays an ABA-deficient phenotype that can be partially rescued by the externally supplied phytohormone. These results suggest that SPC1/ZDS is essential for biosynthesis of carotenoids and plays a crucial role in plant growth and development.
基金supported by the National Modern Agricultural Industry Technology System Construction Program of China(Grant No.20212BBF63001)the Open Competition Program of Jiangxi Provincial Science and Technology in China(Grant No.20213AAF01001)+2 种基金the Jiangxi Provincial Science and Technology Support Program in China(Grant No.20203BBF63033)the Jiangxi Modern Agricultural Research Collaborative Innovation Project in China(Grant No.JXXTCX202111)the Open Project of State Key Laboratory of Rice Biology in China(Grant No.20200101)。
文摘Deep rooting is an important trait in rice drought resistance.Genetic resources of deep-rooting varieties are valuable in breeding of water-saving and drought-resistant rice.In the present study,234BC2F7 backcross introgression lines were derived from a cross of Dongye 80(an accession of Dongxiang wild rice as the donor parent)and R974(an indica restorer line as the recurrent parent).A genetic linkage map containing 1977 bin markers was constructed by ddRADSeq for QTL analysis.Thirty-one QTLs for four root traits(the number of deep roots,the number of shallow roots,the total number of deep roots and the ratio of deep roots)were assessed on six rice chromosomes in two environments(2020 Shanghai and 2021 Hainan).Two of the QTLs,qDR5.1 and qTR5.2,were located on chromosome 5 in a 70-kb interval.They were detected in both environments.qDR5.1 explained 13.35%of the phenotypic variance in 2020 Shanghai and 12.01%of the phenotypic variance in 2021 Hainan.qTR5.2 accounted for 10.88%and 10.93%of the phenotypic variance,respectively.One QTL(qRDR2.2)for the ratio of deep roots was detected on chromosome 2 in a 210-kb interval and accounted for 6.72%of the phenotypic variance in 2020.The positive effects of these three QTLs were all from Dongxiang wild rice.Furthermore,nine and four putative candidate genes were identified in qRDR2.2 and qDR5.1/qTR5.2,respectively.These findings added to our knowledge of the genetic control of root traits in rice.In addition,this study will facilitate the future isolation of candidate genes of the deep-rooting trait and the utilization of Dongxiang wild rice in the improvement of rice drought resistance.
基金supported by the National Basic Research Program of China (No. 2009CB941503)
文摘Complex I （the NADH：ubiquinone oxidoreductase） of the mitochondrial respiratory chain is a complicated, multi-subunit, membrane- bound assembly and contains more than 40 different proteins in higher plants. In this paper, we characterize the Arabidopsis homologue （designated as AtCIB22） of the B22 subunit of eukaryotic mitochondriai Complex I. AtCIB22 is a single-copy gene and is highly con- served throughout eukaryotes. AtCIB22 protein is located in mitochondria and the AtC1B22 gene is widely expressed in different tissues. Mutant Arabidopsis plants with a disrupted AtC1B22 gene display pleiotropic phenotypes including shorter roots, smaller plants and de- layed flowering. Stress analysis indicates that the AtC1B22 mutants＇ seed germination and early seedling growth are severely inhibited by sucrose deprivation stress but more tolerant to ethanol stress. Molecular analysis reveals that in moderate knockdown AtCIB22 mutants, genes including cell redox proteins and stress related proteins are significantly up-regulated, and that in severe knockdown AtCIB22 mu- tants, the alternative respiratory pathways including NDA1, NDB2, AOXla and AtPUMP1 are remarkably elevated. These data demon- strate that AtCIB22 is essential for plant development and mitochondrial electron transport chains in Arabidopsis. Our findings also en- hance our understanding about the physiological role of Complex I in plants.
基金supported by grants from the National Natural Science Foundation of China(No.81071943)the Foundation of Natural Sciences of Hubei Province of China(No.2007ABA072)
文摘P-450-dependent epoxygenase pathway of arachidonic acid and the products of epoxyeicosatrienoic acids（EETs） have been demonstrated to be involved in angiogenesis and tumor progression.This study examined the expression of EETs and the role of the pathway in the angiogenesis of multiple myeloma（MM）.MM cell lines of U266 and RPMI8226 were cultured,and the EETs levels（11,12-EET and 14,15-EET） in the supernatant were determined by ELISA.Human umbilical vein endothelial cells（HUVECs） were cultured and used for analysis of the angiogenesis activity of the two MM cell lines,which was examined both in vitro and in vivo by employing MTT,chemotaxis,tube formation and matrigel plug assays.11,12-EET and 14,15-EET were found in the supernatant of the cultured MM cells.The levels of the two EETs in the supernatant of U266 cells were significantly higher than those in the RPMI8226 cell supernatant（P〈0.05）,and the levels paralleled the respective angiogenesis activity of the two different MM cell lines.17-octadecynoic acid（17-ODYA）,as a specific inhibitor of P450 enzyme,suppressed HUVECs proliferation and tube formation induced by MM cells.Furthermore,17-ODYA decreased the EET levels in the supernatant of MM cells.These results suggest that EETs may play an important role in the angiogenesis of MM,and the inhibitor 17-ODYA suppresses this effect.
