Physiology and Molecular Biology of Plants最新文献

An experiment was performed to understand the effects of aluminium toxicity (AlCl₃·6H₂O) on Kachai lemon growth and development. The toxic effects of aluminium were assessed for 45 days in sand media. With untreated pots serving as the control, seedlings of 1 month old were exposed to three concentrations of AlCl₃·6H₂O: 300 μM, 600 μM and 900 μM. The nutrient Hoagland solution was also given to seedlings along with the Aluminium (Al) treatment. The outcome demonstrated that the chlorophyll content and carotenoids declined with the increase of the concentration levels of AlCl₃·6H₂O and interval of treatment. The contents of O₂ ^·- (Super oxide anion), H₂O₂ (Hydrogen peroxide) and OH (Hydroxyl radical) in seedlings increased with the higher concentration levels of aluminium and longer exposure to Al. Additionally, the activity of the enzymes catalase, superoxide dismutase, ascorbate peroxidase, peroxidase and glutathione reductase were increased in seedlings. Different non-enzymatic antioxidants' actions like tocopherol and Vitamin C played important defence mechanisms for the maintenance of tolerance in aluminium toxicity by increasing their content with an increase in the concentration of treatment levels in Kachai Lemon.

Strawberry (Fragaria × ananassa) production has been greatly hampered by anthracnose crown rot caused by Colletotrichum fructicola. Crown, the modified stem of strawberry, is a sink organ involved in sugar allocation. Some Sugar Transport Proteins (STPs) are involved in competition for sugars between pathogen and host. However, the chemical nature and involvement of strawberry STPs (FaSTPs) in crown rot development is largely elusive. To reveal how strawberry alters soluble sugars and upregulates STPs in responses to C. fructicola, high performance liquid chromatograph and FaSTP expression analysis were performed in the crowns of three strawberry varieties, following a genome-wide identification of FaSTPs. Both C. fructicola and mock treatment/control changed glucose, fructose and sucrose accumulation in strawberry crowns. With increasing infection duration, the hexose/sucrose ratio increased in all varieties; no such trend was clearly visible in mock-treated plants. A total of 56 FaSTP loci scattered across four subgenomes were identified in octoploid strawberry, and most of the protein products of these genes had a preferential location on plasma membrane. Putative fungal elicitor responsive cis-elements were identified in the promoters of more than half FaSTPs. At least eight members were upregulated in strawberry crowns during C. fructicola invasion. Of them, FaSTP8 expression was markedly enhanced in three varieties at all time points except for 3 dpi in 'Jiuxiang'. RNAseq data retrieval further validated the expression responses of FaSTPs to Colletotrichum spp. In summary, this work identified several FaSTP candidate genes responsive to Colletotrichum fructicola invasion, demonstrated changes in soluble sugar levels in strawberry crowns as a result of infection, and laid the groundwork for future efforts to engineer strawberry resistance to Colletotrichum spp.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-024-01523-9.

Seed germination is a tightly regulated, non-reversible developmental process, and it is crucial to prevent premature germination under conditions that may not allow the plant's life cycle to be completed. The plant hormone ABA is the key regulator of seed dormancy and inhibition of germination. ABA is also involved in the plant response to drought. Here we report on the involvement of Arabidopsis thaliana PUB41, encoding a U-BOX E3 ubiquitin ligase, in regulating ABA signaling, seed dormancy, germination, and drought resilience. AtPUB41 is expressed in most vegetative and reproductive tissues. AtPUB41 protein is localized in the cytosol and nucleus. pub41 T-DNA insertion mutants display reduced seed dormancy, and their germination is less inhibited by exogenous ABA than seeds of wild-type plants. pub41 mutant plants are also hypersensitive to drought. ABA induces AtPUB41 promoter activity and steady-state mRNA levels in the roots. Our data suggest that AtPUB41 is a positive regulator of ABA signaling.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-024-01526-6.

Production of stevioside and rebaudioside in Stevia rebaudiana is greatly affected due to extreme environmental conditions. MicroRNAs are known to play an important role in post-transcriptional gene regulation. Here, the aim was to study the effect of abiotic stresses on the Stevia plantlets and then to identify and validate the expression of the conserved microRNAs and their targets under abiotic stress conditions. The effect of dehydration, salinity and cold stress treatment on 7-week-old Stevia plantlets was analyzed. Plant growth, relative water content, malondialdehyde content and antioxidant activity were greatly affected under stress treatment. In the present investigation, amongst the various abiotic stresses studied, 9% PEG treatment greatly affected the Stevia plantlets. To identify the microRNAs, BLAST analysis was performed. A homology search of known miRNAs from the PMRD database against non-redundant Stevia genomic sequences resulted in the prediction of 37 conserved miRNAs and their targets were identified using the psRNATarget server. All the predicted miRNAs had lengths of 20, 21, 22, 23, 24, and 25 nucleotides, respectively. The identified potential conserved miRNAs belong to 34 distinct miRNA families. The highest potential miRNAs are represented by miR169 family followed by miR156, miR172, and miR396 families. Promoter analysis of miRNA-targets genes revealed the presence of numerous cis-acting regulatory elements involved in hormonal and stress-response mechanisms. Further, expression analysis revealed an inverse correlation between the selected identified miRNAs and their targets under abiotic stress treatments. Identifying stress-responsive miRNAs and their targets will help us understand the molecular mechanisms of stress tolerance in Stevia.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-024-01527-5.

The NAC (NAM, ATAF1/2 and CUC2) transcription factors (TFs) play important roles in rice abiotic stress tolerance. OsNAC15 has been reported to regulate zinc deficiency and cadmium tolerance. However, the roles of OsNAC15 in rice drought and salt tolerance are largely unknown. In this study, we characterized a nuclear-localized NAC TF in rice, OsNAC15, that positively regulates drought and salt tolerance and directly participates in the biosynthesis of abscisic acid (ABA). Drought and salt treatment significantly induce the expression of OsNAC15. Loss of OsNAC15 could made plants more sensitive to drought and salt stress and led to the accumulation of more H₂O₂ and malondialdehyde (MDA) in vivo after drought and salt stress, while overexpression of OsNAC15 in plants showed stronger tolerance to drought and salt stress. Results of yeast one-hybrid assay and dual-luciferase (LUC) assay revealed that OsNAC15 interacted with the promoters of nine-cis-epoxycarotenoid dehydrogenases (NCEDs) genes (OsNCED1, OsNCED2 and OsNCED5), which are essential genes for ABA biosynthesis in rice, and promoted the expression of these target genes. In summary, our study reveals that OsNAC15, a NAC TF, may enhance drought and salt tolerance in rice by activating the promoters of key ABA biosynthesis genes (OsNCED1, OsNCED2 and OsNCED5). These results can contribute to further study on the regulatory mechanisms of drought and salt tolerance in rice.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-024-01529-3.

The current study is the first comprehensive report on the expression of fibrinogen binding protein (FIB) antigen in the genetically engineered switchgrass. Mammary tissue inflammation is one of the major infectious diseases caused by Staphylococcus aureus in the dairy animals. The aim of the present study is to develop an efficient and economical bioengineered immunogen for controlling mastitis in developing countries. Plant parts are served as bio-factories to produce antigens against infectious diseases. In this research, mastitis antigenic target (FIB) of S. aureus was expressed in switchgrass via Ag-nanoparticle mediated nuclear gene transformation to ease oral delivery of FIB antigen. FIB gene was cloned in expression vector through TOPO and Gateway cloning method. Transformation and integration of transgene was confirmed through PCR. The maximum concentration of total soluble fraction of FIB was calculated, and total soluble protein accumulated up to 0.5%. The recombinant FIB protein was purified and extract was prepared. FIB protein induced humoral immune response in mice and immunized orally. To administration oral immunogens against mastitis, FIB from S. aureus was commercially synthesized and PCR purified, the purified FIB gene was cloned into expression vector. Ag-NPs were encapsulated with pFIB and used as nanocarrier to target delivery of gene in forage grass. Forage seeds were successfully transformed through nuclear delivery and presence of transgene was confirmed through polymerase chain reaction. Transgenic lines of forage grass expressing FIB antigen is successfully developed. The transgenic lines expressing FIB gene were used for mouse study and in-vivo trials showed that switchgrass as transgenic immunogen developed antibodies in blood of animals upon orally delivering the FIB antigen. The expression of mastitis antigen in edible plants could contribute significantly to the development of cost effective and orally administered antigen-based subunit immunogen against dairy mastitis.

As components of a family of proteins with peptidyl-prolyl isomerase activity family, FKBP (FK506-binding protein) and CYP (Cyclophilins) exert crucial roles in various physiological and biochemical processes such as cell signal transduction and stress resistance. The functions of the FKBP or CYP family have been extensively discussed in various organisms, while the comprehensive characterization of this family in Setaria italica remains unreported. In this study, a total of 22 SiFKBPs and 26 SiCYPs genes were identified in the genome of Setaria italica, with highly conserved functional domains observed within each member of these gene families. Phylogenetic analysis revealed that both FKBP and CYP proteins from Setaria italica and other plant species clustered into nine distinct groups. Furthermore, RT-qPCR results indicated that certain genes were induced specifically under salt stress while others were induced under heat stress, suggesting their involvement in stress response processes. The analysis of gene function revealed that SiFKBP16-3 exhibits some degree of functional conservation.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-024-01530-w.

Pepino (Solanum muricatum), native to the Andes Mountains, requires exogenous hormones in its brief frost-free plateau environment to induce parthenocarpy and ensure yield.The effects of different plant growth regulators and application methods on pepino's growth, yield, and fruit quality were analyzed. Results showed that exogenous plant growth regulators had significant effects on various plant traits For instance, plant height decreased by 43.56% in the flower dipping treatment with 40 parts per million (ppm) 2,4-Dichlorophenoxyacetic acid (2,4-D), while stem diameter decreased by 21.6% with 40 ppm 4-Chlorophenoxyacetic acid (4-CPA) spraying, indicating a notable inhibition of vegetative growth. In contrast, reproductive growth improved, with the 20 ppm 2,4-D spray treatment boosting yield by 627.06% compared to the control. Furthermore, the 30 ppm 2,4-D spray produced the highest single fruit weight, a 69.16% increase over the control. However, exogenous hormones also caused fruit cracking, with the highest rate (55.5%) in the 20 ppm 2,4-D spray treatment. As for fruit quality, glucose content decreased, while fructose and sucrose levels significantly increased in hormone-treated fruits compared to the control. No significant differences were observed in flavonoid, total phenol, or vitamin C content. Transcriptome sequencing showed that 16,836 genes were significantly downregulated in pepino flower buds 72 h after a 30 ppm 4-CPA spray. KEGG enrichment analysis suggested that 4-CPA regulates parthenocarpy by influencing amino acid and protein synthesis pathways. Applying plant growth regulators in different concentrations and methods significantly impacts pepino's growth, yield, and fruit quality. These findings could guide other crops facing similar environmental challenges and potentially transform agricultural practices in high-altitude regions.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-024-01533-7.

Sophora tonkinensis is a significant medicinal plant indigenous to China and Vietnam. In China, S. tonkinensis is mainly grown naturally on limestone mountains or is cultivated artificially in arable land. Heavy metal contamination in agricultural soil, particularly cadmium (Cd), poses serious threats to soil health, as well as the growth and productivity of S. tonkinensis. However, information regarding the physiological and metabolic mechanism of S. tonkinensis under Cd toxicity conditions remains limited. In this study, a hydroponic experiment was conducted to investigate the physiological and metabolic responses of S. tonkinensis to varying concentrations of Cd (0, 20, 40, 60, 80 μM), designated as T0, T1, T2, T3, and T4 respectively. The results indicated that the Cd stress significantly impaired the growth and physiological activity of S. tonkinensis. Specifically, reductions were observed in plant height (15.3% to 37.1%) along with shoot fresh weight (9.6% to 36.3%), shoot dry weight (8.2% to 34.1%), root fresh weight (6.7% to 38.2%) and root dry weight (5.1% to 51.3%). This impairment was attributed to a higher uptake and accumulation of Cd in the roots. The decrease in growth was closely linked to the increased production of reactive oxygen species (ROS), which led to cellular damage under Cd toxicity; however, increased antioxidant enzyme activities improved the stress tolerance of S. tonkinensis's stress to Cd toxicity. Non-targeted metabolomic analyses identified 380 differential metabolites (DMs) in the roots of S. tonkinensis subjected to varying level of Cd stress, including amino acids, organic acids, fatty acids, ketones, and others compounds. Further KEGG pathway enrichment analysis revealed that several pathways, such as ABC transporters, isoflavonoid biosynthesis, and pyrimidine metabolism were involved in the response to Cd. Notably, the isoflavonoid biosynthesis pathway was significantly enriched in both T0 vs. T2 and T0 vs. the higher level (80 μM) of Cd stress, highlighting its significance in the plant responses to Cd stress. In conclusion, the identification of key pathways and metabolites is crucial for understanding Cd stress tolerance in S. tonkinensis.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-024-01522-w.

Soil cadmium (Cd) contamination in agriculture has intensified due to industrial development and human activities, which seriously affected the safety production in wheat. There are increasing evidences that rhizosphere bacteria contributed to alleviating Cd stress in plants, but the mechanism of how rhizosphere bacteria affecting the adaptive growth of wheat exposed to Cd contamination has not been extensively explored. Therefore, the rhizosphere bacterial community dynamics and plant growth for wheat were investigated under different levels of soil Cd contamination in accordance with risk control standard for soil contamination of agricultural land. The results showed that there was no significant difference in transport coefficient of Cd in wheat plants grown in different levels of soil Cd contamination conditions. Soil Cd contamination led to a decrease in soil pH value and an increase in exchangeable Cd content in rhizosphere soil. Although rhizosphere bacterial richness and diversity had no significant difference between soil Cd contamination conditions, as its community composition changed significantly. Under Cd contamination of risk screening value, Actinobacteria, Chloroflexi, and Nitrospira showed higher abundance, but Bacteroidetes, Patescibacteria, Sphingomonas, ADurbBin063-1 and Bryobacter were more prevalent under Cd contamination of risk intervention value. The enrichment of Patescibacteria, Proteobacteria and Acidobacteria was beneficial for Cd fixation, while Nitrospira enhanced nutrient uptake and utilization. Furthermore, Cd contamination with risk screening value enhanced the relationship among rhizosphere bacterial communities, and Cd contamination with risk intervention value increased the cooperative relationship among rhizosphere bacterial species. Additionally, soil Cd content showed a significantly positive correlation with Patescibacteria and ADurbBin063-1, and a significantly negative correlation with pH. Altogether, the shift in the community structures of rhizosphere bacterial was crucial for farmland protection and food safety in Cd polluted soil.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-024-01532-8.