Combined application of biochar and peatmoss for mitigation of drought stress in tobacco.

Drought poses a significant ecological threat that limits the production of crops worldwide. The objective of this study to examine the impact of soil applied biochar (BC) and peatmoss (PM) on the morpho-biochemical and quality traits of tobacco plants under drought conditions. In the present experiment work, a pot trial was conducted with two levels of drought severity (~ well-watered 75 ± 5% field capacity) and severe drought stress (~ 35 ± 5% field capacity), two levels of peatmoss (PM) @ 5% [PM+ (with peatmoss) and PM- (without peatmoss)] and three levels of rice straw biochar (BC0 = no biochar; BC1 = 150 mg kg- 1; and BC2 = 300 mg kg- 1 of soil) in tobacco plants. The results indicate that drought conditions significantly impacted the performance of tobacco plants. However, the combined approach of BC and PM significantly improved the growth, biomass, and total chlorophyll content (27.94%) and carotenoids (32.00%) of tobacco. This study further revealed that the drought conditions decreased the production of lipid peroxidation and proline accumulation. But the synergistic approach of BC and PM application increased soluble sugars (17.63 and 12.20%), soluble protein (31.16 and 15.88%), decreased the proline accumulation (13.92 and 9.03%), and MDA content (16.40 and 8.62%) under control and drought stressed conditions, respectively. Furthermore, the combined approach of BC and PM also improved the leaf potassium content (19.02%) by limiting the chloride ions (33.33%) under drought stressed conditions. Altogether, the balanced application of PM and BC has significant potential as an effective approach and sustainable method to increase the tolerance of tobacco plants subjected to drought conditions. This research uniquely highlights the combined potential of PM and BC as an eco-friendly strategy to enhance plant resilience under drought conditions, offering new insights into sustainable agricultural practices.

Artemisia annua ZFP8L regulates glandular trichome development.

Trichomes are known to be important biofactories that contribute to the production of secondary metabolites, such as terpenoids. C2H2-zinc finger proteins (C2H2-ZFPs) are vital transcription factors of plants' trichome development. However, little is known about the function of Artemisia annua C2H2-ZFPs in trichome development. To explore the roles of this gene family in trichome development, two C2H2-ZFP transcription factors, named AaZFP8L and AaGIS3, were identified; both are hormonally regulated in A. annua. Overexpression of AaZFP8L in tobacco led to a significant increase in the density and length of glandular trichomes, and improved terpenoid content. In contrast, AaGIS3 was found to positively regulate non-glandular trichome initiation and elongation, which reduces terpenoid accumulation. In addition, ABA contents significantly increased in AaZFP8L-overexpressing tobacco lines and AaZFP8L also can directly bind the promoter of the ABA biosynthesis genes. This study lays the foundation for further investigating A. annua C2H2-ZFPs in trichome development and terpenoid accumulation.

A novel AP2/ERF transcription factor, NtERF10, positively regulates plant height in tobacco.

Ethylene response factors have been shown to be involved in the effects of plant developmental processes and to regulate stress tolerance. The aim of this study was to recognize the regulatory mechanisms of ethylene response factors on tobacco plant height. In this study, a gene-edited mutant (ERF10-KO) and wild type (WT) were utilized as experimental materials. Transcriptome and metabolome analyses were used to investigate the regulatory mechanism of NtERF10 gene editing on plant height in tobacco. Here, through the analysis of differentially expressed genes (DEGs), 2051 genes were upregulated and 1965 genes were downregulated. We characterized the different ERF10-KO and WT plant heights and identified key genes for photosynthesis, the plant hormone signal transduction pathway and the terpene biosynthesis pathway. NtERF10 was found to affect the growth and development of tobacco by regulating the expression levels of the PSAA, PSBA, GLY17 and GGP3 genes. Amino acid metabolism was analyzed by combining analyses of differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs). In addition, we found that members of the bHLH, NAC, MYB, and WRKY transcription factor families have vital roles in regulating plant height. This study not only provides important insights into the positive regulation of the ethylene response factor NtERF10 on plant height during plant growth and development but also provides new research ideas for tobacco molecular breeding.

Enhancing rooting tobacco (Nicotiana tabacum) plant by loaded indole-3-butyric acid in alginate/chitosan nanocapsule.

Recently, nanocarriers have been utilized for encapsulating and sustained release of agrochemicals specifically auxins. Due to their potential applications such as increased bioavailability and improved crop yield and nutritional quality. Herein, the efficacy of alginate/chitosan nanocapsules as a nanocarrier for the hormone indole-3-butyric acid (IBA) loading and its effect on rooting tobacco plants has been carried out in the present study. The average particle size of IBA-alginate/chitosan nanocapsules was measured by Dynamic light scattering analysis at 321 nm. Scanning electron microscope studies revealed the spherical shape of nanoparticles with an average size of 97 nm. The average particle size of IBA-alginate/chitosan nanocapsules was measured by Dynamic light scattering analysis at 321 nm. The characteristic peaks of IBA on alginate/chitosan nanocapsules were identified by Fourier transform infrared spectroscopic analysis. Also, high efficiency (35%) of IBA hormone loading was observed. The findings indicated that the concentration of 3 mgL-1 of IBA-alginate/chitosan nanocapsules has the highest efficiency in increasing the rooting in tobacco (Nicotiana tabacum) plants compared to other treatments. According to our results, we can introduce alginate/chitosan nanocapsules as an efficient nanocarrier in IBA hormone transfer applications and their use in agriculture.

The Complex FtBBX22 and FtHY5 Positively Regulates Light-Induced Anthocyanin Accumulation by Activating FtMYB42 in Tartary Buckwheat Sprouts.

Anthocyanin is one important nutrition composition in Tartary buckwheat (Fagopyrum tataricum) sprouts, a component missing in its seeds. Although anthocyanin biosynthesis requires light, the mechanism of light-induced anthocyanin accumulation in Tartary buckwheat is unclear. Here, comparative transcriptome analysis of Tartary buckwheat sprouts under light and dark treatments and biochemical approaches were performed to identify the roles of one B-box protein BBX22 and ELONGATED HYPOCOTYL 5 (HY5). The overexpression assay showed that FtHY5 and FtBBX22 could both promote anthocyanin synthesis in red-flower tobacco. Additionally, FtBBX22 associated with FtHY5 to form a complex that activates the transcription of MYB transcription factor genes FtMYB42 and FtDFR, leading to anthocyanin accumulation. These findings revealed the regulation mechanism of light-induced anthocyanin synthesis and provide excellent gene resources for breeding high-quality Tartary buckwheat.

Up-regulation of growth-related gene expression in tobacco by volatile compounds released by Bacillus velezensis WSW007.

In order to investigate the mechanism of plant growth promoting (PGP) effects of strain Bacillus velezensis WSW007, its PGP traits and production of volatile organic compounds (VOCs) were tested. The effects of VOCs produced by strain WSW007 on plant growth were observed by co-culturing this strain with tobacco seedlings in I-plates. Meanwhile, the effects of VOCs on tobacco gene expression were analysed by a transcriptome analysis and VOCs were identified by solid phase micro extraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS) analysis. As results, strains WSW007 produced acetic acid and siderophore, and could solubilize phosphate; while it also significantly increased the fresh weight of tobacco seedlings via production of VOCs. In transcriptome analysis, plants co-cultured with strain WSW007 presented the highest up-regulated expression for the genes involved in plant growth and development processes, implying that the bacterial VOCs played a role as regulator of plant gene expression. Conclusively, the up-regulation in expression of growth- and development-related genes via VOCs production is an important PGP mechanism in strain B. velezensis WSW007.

Identification and Functional Studies on the Role of PlSPL14 in Herbaceous Peony Stem Development.

Stem strength plays a crucial role in the growth and development of plants, as well as in their flowering and fruiting. It not only impacts the lodging resistance of crops, but also influences the ornamental value of ornamental plants. Stem development is closely linked to stem strength; however, the roles of the SPL transcription factors in the stem development of herbaceous peony (Paeonia lactiflora Pall.) are not yet fully elucidated. In this study, we obtained and cloned the full-length sequence of PlSPL14, encoding 1085 amino acids. Quantitative real-time PCR (qRT-PCR) analysis revealed that the expression level of PlSPL14 gradually increased with the stem development of P. lactiflora and was significantly expressed in vascular bundles. Subsequently, utilizing the techniques of virus-induced gene silencing (VIGS) and heterologous overexpression in tobacco (Nicotiana tabacum L.), it was determined that PlSPL14-silenced P. lactiflora had a thinner xylem thickness, a decreased stem diameter, and weakened stem strength, while PlSPL14-overexpressing tobacco resulted in a thicker xylem thickness, an increased stem diameter, and enhanced stem strength. Further screening of the interacting proteins of PlSPL14 using a yeast two-hybrid (Y2H) assay revealed an interactive relationship between PlSPL14 and PlSLR1 protein, which acts as a negative regulator of gibberellin (GA). Additionally, the expression level of PlSLR1 gradually decreased during the stem development of P. lactiflora. The above results suggest that PlSPL14 may play a positive regulatory role in stem development and act in the xylem, making it a potential candidate gene for enhancing stem straightness in plants.

Genome-wide analysis of Citrus medica ABC transporters reveals the regulation of fruit development by CmABCB19 and CmABCC10.

ATP-binding cassette (ABC) transporters are vital for plant growth and development as they facilitate the transport of essential molecules. Despite the family's significance, limited information exists about its functional distinctions in Citrus medica. Our study identified 119 genes encoding ABC transporter proteins in the C. medica genome. Through an evolutionary tree and qPCR analysis, two ABC genes, CmABCB19 and CmABCC10, were implicated in C. medica fruit development, showing upregulation in normal fruits compared to malformed fruits. CmABCB19 was found to localize to the plasma membrane of Nicotiana tabacum, exhibiting indole-3-acetic acid (IAA) efflux activity in the yeast mutant strain yap1. CmABCC10, a tonoplast-localized transporter, exhibited efflux of diosmin, nobiletin, and naringin, with rutin influx in strain ycf1. Transgenic expression of CmABCB19 and CmABCC10 in Arabidopsis thaliana induced alterations in auxin and flavonoid content, impacting silique and seed size. This effect was attributed to the modulation of structural genes in the auxin biosynthesis (YUC5/9, CYP79B2, CYP83B1, SUR1) and flavonoid biosynthesis (4CL2/3, CHS, CHI, FLS1/3) pathways. In summary, the functional characterization of CmABCB19 and CmABCC10 illuminates auxin and flavonoid transport, offering insights into their interplay with biosynthetic pathways and providing a foundation for understanding the transporter's role in fruit development.

Integrative proteome and metabolome unveil the central role of IAA alteration in axillary bud development following topping in tobacco.

Axillary bud is an important aspect of plant morphology, contributing to the final tobacco yield. However, the mechanisms of axillary bud development in tobacco remain largely unknown. To investigate this aspect of tobacco biology, the metabolome and proteome of the axillary buds before and after topping were compared. A total of 569 metabolites were differentially abundant before and 1, 3, and 5 days after topping. KEGG analyses further revealed that the axillary bud was characterized by a striking enrichment of metabolites involved in flavonoid metabolism, suggesting a strong flavonoid biosynthesis activity in the tobacco axillary bud after topping. Additionally, 9035 differentially expressed proteins (DEPs) were identified before and 1, 3, and 5 days after topping. Subsequent GO and KEGG analyses revealed that the DEPs in the axillary bud were enriched in oxidative stress, hormone signal transduction, MAPK signaling pathway, and starch and sucrose metabolism. The integrated proteome and metabolome analysis revealed that the indole-3-acetic acid (IAA) alteration in buds control dormancy release and sustained growth of axillary bud by regulating proteins involved in carbohydrate metabolism, amino acid metabolism, and lipid metabolism. Notably, the proteins related to reactive oxygen species (ROS) scavenging and flavonoid biosynthesis were strongly negatively correlated with IAA content. These findings shed light on a critical role of IAA alteration in regulating axillary bud outgrowth, and implied a potential crosstalk among IAA alteration, ROS homeostasis, and flavonoid biosynthesis in tobacco axillary bud under topping stress, which could improve our understanding of the IAA alteration in axillary bud as an important regulator of axillary bud development.

Integrative analysis of microbiome and metabolome revealed the effect of microbial inoculant on microbial community diversity and function in rhizospheric soil under tobacco monoculture.

Over-application of chemical fertilizers and continuous cropping obstacles seriously restrict the sustainable development of tobacco production. Localized fertilization of beneficial microbes has potential advantages in achieving higher productivity, but the underlying biological mechanisms of interactions between rhizospheric microorganisms and the related metabolic cycle remain poorly characterized. Here, an integrative analysis of microbiomes with non-targeted metabolomics was performed on 30 soil samples of rhizosphere, root surrounding, and bulk soils from flue-cured tobacco under continuous and non-continuous monocropping systems. The analysis was conducted using UPLC-MS/MS platforms and high-throughput amplicon sequencing targeting the bacterial 16S rRNA gene and fungal ITS gene. The microbial inoculant consisted of Bacillus subtilis, B. velezensis, and B. licheniformis at the ratio of 1:1:1 in effective microbial counts, improved the cured leaf yield and disease resistance of tobacco, and enhanced nicotine and nitrogen contents of tobacco leaves. The bacterial taxa Rhizobium, Pseudomonas, Sphingomonadaceae, and Burkholderiaceae of the phylum Proteobacteria accumulated in high relative abundance and were identified as biomarkers following the application of the microbial inoculant. Under continuous monocropping, metabolomics demonstrated that the application of the microbial inoculant significantly affected the soil metabolite spectrum, and the differential metabolites were significantly enriched to the synthesis and degradation of nicotine (nicotinate and nicotinamide metabolism and biosynthesis of alkaloids derived from nicotinic acid). In addition, microbes were closely related to the accumulation of metabolites through correlation analysis. The interactions between plant roots and rhizospheric microorganisms provide valuable information for understanding how these beneficial microbes affect complex biological processes and the adaption capacity of plants to environments.IMPORTANCEThis study elaborated on how the microbial fertilizer significantly changed overall community structures and metabolite spectrum of rhizospheric microbes, which provide insights into the process of rhizosphere microbial remolding in response to continuous monocropping. we verified the hypothesis that the application of the microbial inoculant in continuous cropping would lead to the selection of distinct microbiota communities by establishing models to correlate biomarkers. Through correlation analysis of the microbiome and metabolome, we proved that rhizospheric microbes were closely related to the accumulation of metabolites, including the synthesis and degradation of nicotine. The interactions between plant roots and rhizospheric microorganisms provide valuable information for understanding how these beneficial microbes affect complex biological processes and the adaption capacity of plants to environments.

Shallow water seeding cultivation enhances cold tolerance in tobacco seedlings.

Cold stress can impact plant biology at both the molecular and morphological levels. We cultivated two different types of tobacco seedlings using distinct seeding methods, observing significant differences in their cold tolerance at 4 °C. After 12 h cold stress, shallow water seeding cultivation treatment demonstrates a relatively good growth state with slight wilting of the leaves. Tobacco grown using the float system exhibited short, thick roots, while those cultivated through shallow water seeding had elongated roots with more tips and forks. After cold stress, the shallow water seeding cultivation treatment demonstrated higher antioxidant enzyme activity, and lower malondialdehyde (MDA) content.Transcriptome analysis was performed on the leaves of these tobacco seedlings at three stages of cold treatment (before cold stress, after cold stress, and after 3 days of recovery). Upon analyzing the raw data, we found that the shallow water seeding cultivation treatment was associated with significant functional enrichment of nicotinamide adenine dinucleotide (NAD) biosynthesis and NAD metabolism before cold stress, enrichment of functions related to the maintenance of cellular structure after cold stress, and substantial functional enrichment related to photosynthesis during the recovery period. Weighted gene co-expression network analysis (WGCNA) was conducted, identifying several hub genes that may contribute to the differences in cold tolerance between the two tobacco seedlings. Hub genes related to energy conversion were predominantly identified in shallow water seeding cultivation treatment during our analysis, surpassing findings in other areas. These include the AS gene, which controls the synthesis of NAD precursors, the PED1 gene, closely associated with fatty acid ß-oxidation, and the RROP1 gene, related to ATP production.Overall, our study provides a valuable theoretical basis for exploring improved methods of cultivating tobacco seedlings. Through transcriptome sequencing technology, we have elucidated the differences in gene expression in different tobacco seedlings at three time points, identifying key genes affecting cold tolerance in tobacco and providing possibilities for future gene editing.

LbCOPT1 is a copper transporter induced in Lycium barbarum mycorrhizal roots, which allows tobacco with improved growth and nutrient uptake.

KEY MESSAGE: Overexpressing the copper transporter LbCOPT1 leads to a notable increase in the abundance of mycorrhizal arbuscules that suggests the potential application of LbCOPT1 in breeding programs aimed at enhancing symbiotic nutrient uptake in Lycium barbarum L.

Transcriptome profiling reveals the impact of various levels of biochar application on the growth of flue-cured tobacco plants.

BACKGROUND: Biochar, a carbon-rich source and natural growth stimulant, is usually produced by the pyrolysis of agricultural biomass. It is widely used to enhance plant growth, enzyme activity, and crop productivity. However, there are no conclusive studies on how different levels of biochar application influence these systems. METHODS AND RESULTS: The present study elucidated the dose-dependent effects of biochar application on the physiological performance, enzyme activity, and dry matter accumulation of tobacco plants via field experiments. In addition, transcriptome analysis was performed on 60-day-old (early growth stage) and 100-day-old (late growth stage) tobacco leaves to determine the changes in transcript levels at the molecular level under various biochar application levels (0, 600, and 1800 kg/ha). The results demonstrated that optimum biochar application enhances plant growth, regulates enzymatic activity, and promotes biomass accumulation in tobacco plants, while higher biochar doses had adverse effects. Furthermore, transcriptome analysis revealed a total of 6561 differentially expressed genes (DEGs) that were up- or down-regulated in the groupwise comparison under different treatments. KEGG pathways analysis demonstrated that carbon fixation in photosynthetic organisms (ko00710), photosynthesis (ko00195), and starch and sucrose metabolism (ko00500) pathways were significantly up-regulated under the optimal biochar dosage (600 kg/ha) and down-regulated under the higher biochar dosage (1800 kg/ha). CONCLUSION: Collectively, these results indicate that biochar application at an optimal rate (600 kg/ha) could positively affect photosynthesis and carbon fixation, which in turn increased the synthesis and accumulation of sucrose and starch, thus promoting the growth and dry matter accumulation of tobacco plants. However, a higher biochar dosage (1800 kg/ha) disturbs the crucial source-sink balance of organic compounds and inhibits the growth of tobacco plants.

Hydroponic Growth of [13C]-Labeled Tobacco for DNA Damage Studies in Cigarette Smokers.

Cigarette smoking is the acknowledged major cause of cancers of the lung and oral cavity and is an established important risk factor for multiple other cancers. DNA addition products (DNA adducts) caused by cigarette smoking are critical factors in its mechanism of carcinogenesis. However, most DNA adducts detected to date in humans cannot be specifically ascribed to smoking but rather have multiple exogenous and endogenous sources. In the study reported here, we prepared [13C]-labeled tobacco to address this problem. We report for the first time the successful growth from seeds to flowering under hydroponic conditions of highly [13C]-labeled tobacco in a controlled 13CO2 environment. The standard growth procedure with optimized conditions is described in detail. The [13C]-enrichment rate was assessed by quantifying nicotine and sugars and their [13C]-isotopologues in this tobacco using high-resolution mass spectrometry, reaching >94% in the tobacco leaves. The [13C]-labeled leaves after curing will be used to make cigarettes, allowing investigation of the specific contributions of tobacco smoke carcinogens to identified DNA adducts in smokers.

Rice Big Grain1 improves grain yield in ectopically expressing rice and heterologously expressing tobacco plants.

Functional genomics through transgenesis has provided faster and more reliable methods for identifying, characterizing, and utilizing genes or quantitative trait loci linked to agronomic traits to target yield. The present study explored the role of Big Grain1 (BG1) gene of rice (Oryza sativa L.) in yield improvement of crop plants. We aimed to identify the genetic variation of OsBG1 in various indica rice cultivars by studying the allelic polymorphism of the gene, while also investigating the gene's potential to increase crop yield through the transgenic approach. Our study reports the presence of an extra 393 bp sequence having two 6 bp enhancer elements in the 3' regulatory sequence of OsBG1 in the large-grain cultivar IR64 but not in the small-grain cultivar Badshahbhog. A single copy of the OsBG1 gene in both the cultivars and a 4.1-fold higher expression of OsBG1 in IR64 than in Badshahbhog imply that the grain size is positively correlated with the level of OsBG1 expression in rice. The ectopic expression of OsBG1 under the endosperm-specific glutelin C promoter in Badshahbhog enhanced the flag leaf length, panicle weight, and panicle length by an average of 33.2%, 33.7%, and 30.5%, respectively. The length of anthers, spikelet fertility, and grain yield per plant increased in transgenic rice lines by an average of 27.5%, 8.3%, and 54.4%, respectively. Heterologous expression of OsBG1 under the constitutive 2xCaMV35S promoter improved the number of seed pods per plant and seed yield per plant in transgenic tobacco lines by an average of 2.2-fold and 2.6-fold, respectively. Improving crop yield is crucial to ensure food security and socio-economic stability, and identifying suitable genetic factor is the essential step towards this endeavor. Our findings suggest that the OsBG1 gene is a promising candidate for improving the grain yield of monocot and dicot plant systems by molecular breeding and genetic engineering.

Rotation with other crops slow down the fungal process in tobacco-growing soil.

Continuous cultivation of tobacco could cause serious soil health problems, which could cause bacterial soil to change to fungal soil. In order to study the diversity and richness of fungal community in tobacco-growing soil under different crop rotation, three treatments were set up in this study: CK (tobacco continuous cropping); B (barley-tobacco rotation cropping) and R (oilseed rape-tobacco rotation cropping). The results of this study showed that rotation with other crops significantly decreased the soil fungal OTUs, and also decreased the community richness, evenness, diversity and coverage of fungal communities. Among them, B decreased the most. In the analysis of the composition and structure of the fungal community, it was found that the proportion of plant pathogens Nectriaceae decreased from 19.67% in CK to 5.63% in B, which greatly reduced the possibility of soil-borne diseases. In the analysis of the correlation between soil environmental factors and fungal communities, it was found that Filobasidiaceae had a strong correlation with TP and AP, and Erysiphaceae had a strong correlation with TK and AK. NO3--N and NH4+-N were the two environmental factors with the strongest correlation with fungal communities. The results of this study showed that rotation with other crops slowed down the process of soil fungi in tobacco-growing soil and changed the dominant species of soil fungi community. At the same time, crop rotation changed the diversity and richness of soil fungal community by changing the physical and chemical properties of soil.

Characterization of YABBY transcription factors in Osmanthus fragrans and functional analysis of OfYABBY12 in floral scent formation and leaf morphology.

BACKGROUND: The plant-specific YABBY transcription factor family plays important roles in plant growth and development, particularly leaf growth, floral organ formation, and secondary metabolite synthesis. RESULTS: Here, we identified a total of 13 OfYABBY genes from the Osmanthus fragrans genome. These 13 OfYABBY genes were divided into five subfamilies through phylogenetic analysis, and genes in the same subfamily showed similar gene structures and conserved protein motifs. Gene duplication promoted the expansion of the OfYABBY family in O. fragrans. Tissue-specific expression analysis showed that the OfYABBY family was mainly expressed in O. fragrans leaves and floral organs. To better understand the role of OfYABBY genes in plant growth and development, OfYABBY12 was selected for heterologous stable overexpression in tobacco, and OfYABBY12-overexpressing tobacco leaves released significantly fewer volatile organic compounds than wild-type tobacco leaves. Overexpression of OfYABBY12 led to the downregulation of NtCCD1/4 and decreased ß-ionone biosynthesis. Correspondingly, a dual-luciferase assay showed that OfYABBY12 negatively regulated the expression of OfCCD4, which promotes ß-ionone synthesis. Furthermore, tobacco leaves overexpressing OfYABBY12 were curled and wrinkled and had significantly reduced leaf thickness and leaf inclusions and significantly extended flower pistils (styles). CONCLUSION: Overall, the results suggest that the OfYABBY gene family may influence the biosynthesis of the floral scent (especially ß-ionone) in O. fragrans and may regulate leaf morphogenesis and lateral organs.

Novel phosphatase PvPAP1 from the As-hyperaccumulator Pteris vittata promotes organic P utilization and plant growth: Extracellular exudation and phytate hydrolysis.

Organic phosphorus (Po) is a large component of soil P, but it is often unavailable for plant uptake. Purple acid phosphatases (PAP) can hydrolyze a wide range of Po, playing an important role in Po utilization by plants. In this study, we investigated a novel secretary PvPAP1 from the As-hyperaccumulator Pteris vittata, which can effectively utilize exogenous Po, including adenosine triphosphate (ATP) and phytate. Unlike other PAP, PvPAP1 was abundantly-expressed in P. vittata roots, which was upregulated 3.5-folds under P-deprivation than P-sufficient conditions. When expressed in tobacco, its activity in the roots of PvPAP1-Ex lines was ∼8 folds greater than that in wild-type (WT) plants. Besides, PvPAP1 exhibited its secretory ability as evidenced by the sapphire-blue color on the root surface after treating with 5-bromo-4-chloro-3-indolyl phosphate. In a long-term experiment using sand media, PvPAP1-expressing tobacco plants showed 25-30 % greater root biomass than WT plants when using ATP as the sole P source. This is because PvPAP1-expression enhanced its phosphatase activity by 6.5-9.2 folds in transgenic tobacco, thereby increasing the P contents by 39-41 % in its roots under ATP treatment and 9.4-30 % under phytate treatment. The results highlight PvPAP1 as a novel secreted phosphatase crucial for external Po utilization in P. vittata, suggesting that PvPAP1 has the potential to serve as a valuable gene resource for enhancing Po utilization by crop plants.

Variety-dependent responses of common tobacco with differential cadmium resistance: Cadmium uptake and distribution, antioxidative activity, and gene expression.

Cadmium (Cd), which accumulates in tobacco leaves, enters the human body through inhalation of smoke, causing harmful effects on health. Therefore, identifying the pivotal factors that govern the absorption and resistance of Cd in tobacco is crucial for mitigating the harmful impact of Cd. In the present study, four different Cd-sensitive varieties, namely, ZhongChuan208 (ZC) with resistance, ZhongYan100 (ZY), K326 with moderate resistance, and YunYan87 (YY) with sensitivity, were cultivated in hydroponic with different Cd concentrations (20 µM, 40 µM, 60 µM and 80 µM). The results indicated that plant growth was significantly decreased by Cd. Irrespective of the Cd concentration, ZC exhibited the highest biomass, while YY had the lowest biomass; ZY and K326 showed intermediate levels. Enzymatic (APX, CAT, POD) and nonenzymatic antioxidant (Pro, GSH) systems showed notable variations among varieties. The multifactor analysis suggested that the ZC and ZY varieties, with higher levels of Pro and GSH content, contribute to a decrease in the levels of MDA and ROS. Among all the Cd concentrations, ZC exhibited the lowest Cd accumulation, while YY showed the highest. Additionally, there were significant differences observed in Cd distribution and translocation factors among the four different varieties. In terms of Cd distribution, cell wall Cd accounted for the highest proportion of total Cd, and organelles had the lowest proportion. Among the varieties, ZC showed lower Cd levels in the cell wall, soluble fraction, and organelles. Conversely, YY exhibited the highest Cd accumulation in all tissues; K326 and ZY had intermediate levels. Translocation factors (TF) varied among the varieties under Cd stress, with ZC and ZY showing lower TF compared to YY and K326. This phenomenon mainly attributed to regulation of the NtNramp3 and NtNramp5 genes, which are responsible for the absorption and transport of Cd. This study provides a theoretical foundation for the selection and breeding of tobacco varieties that are resistant to or accumulate less Cd.

Integrated multi-omics analysis reveals genes involved in flavonoid biosynthesis and trichome development of Artemisia argyi.

Artemisia argyi is an herbaceous plant of the genus Artemisia. Its young and mature leaves are used as food and medicine, respectively. Glandular trichomes (GTs) are distributed on the leaf surface in A. argyi and are generally considered the location of flavonoid biosynthesis and accumulation. However, the mechanism of flavonoid biosynthesis and accumulation in A. argyi remains unclear. In this study, the coregulatory genes involved in flavonoid biosynthesis and trichome development in this species were screened and evaluated, and the biosynthetic pathways for key flavonoids in A. argyi were uncovered. AaMYB1 and AaYABBY1 were screened using weighted gene co-expression network analysis, and both genes were then genetically transformed into Nicotiana tabacum L. cv. K326 (tobacco). Simultaneously, AaYABBY1 was also genetically transformed into Arabidopsis thaliana. The total flavonoid and rutin contents were increased in tobacco plants overexpressing AaMYB1 and AaYABBY1, and the expression levels of genes participating in the flavonoid synthesis pathway, such as PAL, FLS, and F3H, were significantly up-regulated in plants overexpressing these genes. These results indicated that AaMYB1 and AaYABBY1 promote flavonoid biosynthesis in tobacco. Furthermore, compared to that in the wild-type, the trichome density was significantly increased in tobacco and A. thaliana plants overexpressing AaYABBY1. These results confirm that AaYABBY1 might be involved in regulating trichome formation in A. argyi. This indicates the potential genes involved in and provides new insights into the development of trichome cellular factories based on the "development-metabolism" interaction network and the cultivation of high-quality A. argyi.