Journal of plant physiology最新文献

Physalis peruviana L. (P. peruviana) is an edible medicinal plant rich in bioactive phenolics. This study aimed to establish a hairy root (HR) culture of P. peruviana as a potential source for the synthesis of natural compounds. HRs were induced in P. peruviana using different Agrobacterium rhizogenes strains (R1601, C58C1, A4, and K599). Notably, K599 did not induce HR formation, whereas R1601, C58C1, and A4 yielded transformation frequencies of 57.78, 65.14, and 72.31%, respectively. Secondary metabolite production and antioxidant capacity were further examined in HRs induced using C58C1, R1601, and A4. It was found that A. rhizogenes R1601 induced the greatest increase (44% compared to that observed in the non-transformed culture). The methanolic extract of HRs induced by A. rhizogenes R1601 exhibited strong antioxidant capacity, with IC₅₀ values of 1.41 mg DE/mL and 2.33 mg DE/mL for 2,2-diphenyl-1-picrylhydrazyl and 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid), respectively. The HR culture showed higher production of phenolic compounds and higher antioxidant capacity than the non-transformed cultures. Ultra-performance liquid chromatography time-of-flight tandem mass spectrometry was used to identify eight alkaloids, phenolics, and glycoside compounds. A. rhizogenes R1601 is emerging as a possible strain for the mass production of HR and bioactive phenolic compounds in P. peruviana.

As our planet faces increasing environmental challenges, such as biotic pressures, abiotic stressors, and climate change, it is crucial to understand the complex mechanisms that underlie stress responses in crop plants. Over past few years, the integration of techniques of proteomics, transcriptomics, and genomics like LC-MS, IT-MS, MALDI-MS, DIGE, ESTs, SAGE, WGS, GWAS, GBS, 2D-PAGE, CRISPR-Cas, cDNA-AFLP, HLS, HRPF, MPSS, CAGE, MAS, IEF, MudPIT, SRM/MRM, SWATH-MS, ESI have significantly enhanced our ability to comprehend the molecular pathways and regulatory networks, involved in balancing the ecosystem/ecology stress adaptation. This review offers thorough synopsis of the current research on utilizing these multi-omics methods (including metabolomics, ionomics) for battling abiotic (salinity, temperature (chilling/freezing/cold/heat), flood (hypoxia), drought, heavy metals/loids), biotic (pathogens like fungi, bacteria, virus, pests, and insects (aphids, caterpillars, moths, mites, nematodes) and climate change stress (ozone, ultraviolet radiation, green house gases, carbon dioxide). These strategies can expedite crop improvement, and act as powerful tools with high throughput and instant database generation rates. They also provide a platform for interpreting intricate, systematic signalling pathways and knowing how different environmental stimuli cause phenotypic responses at cellular and molecular level by changing the expression of stress-responsive genes like RAB18, KIN1, RD29B, OsCIPK03, OsSTL, SIAGL, bZIP, SnRK, ABF. This review discusses various case studies that exemplify the successful implementation of these omics tools to enhance stress tolerance in plants. Finally, it highlights challenges and future prospects of utilizing these approaches in combating stress, emphasizing the need for interdisciplinary collaborations and bio-technological advancements for sustainable agriculture and food security.

Pollen tubes are crucial for angiosperm plants, as they deliver sperm gametes for the essential process of double fertilization. Understanding the molecular mechanisms behind pollen tube germination and growth is critical; however, these processes remain partially elucidated in monocot cereal crops. Rapid Alkalinization Factor (RALF), a small peptide of about 5 kDa, binds to the CrRLK1L receptor and plays a role in various plant physiological processes, including reproduction and tip growth. Recently, we reported that OsRALF17 and OsRALF19 binds to the OsMTD2, pollen specific CrRLK1L member, and regulates pollen tube growth. In this study, we demonstrate that Ruptured Pollen tube (RUPO), another CrRLK1L member, is also a putative receptor for OsRALF17 and OsRALF19, and propose the formation of a receptor complex with OsMTD2. In tobacco epidermal cells, OsMTD2 and RUPO were co-localized at both the plasma membrane (PM) and the nuclear membrane. Additionally, we generated a RUPO-tagged line driven by its native promoter to visualize subcellular localization during pollen tube growth. RUPO localizes a tip-enriched distribution, with intense fluorescence at the tip's PM and cytoplasm in pollen tube. Upon treatment with synthetic OsRALF17M and OsRALF19M peptides, a reduction in the signal near the PM was observed, suggesting a potential response to these peptides. Our data support the role of RUPO as a candidate receptor for OsRALF17 and OsRALF19 in rice pollen tubes, thereby suggesting a novel mechanism for these RALFs in regulating pollen tube function. Additionally, we observed a significant delay in pollen tube burst time upon treatment with synthetic OsRALF17M and synthetic OsRALF19M. We propose that investigating this phenomenon may provide further insights into the specific signaling pathways mediated by these RALFs.

Plant height determines lodging resistance and is closely linked to yield stability in wheat. In this study, we identified two semi-dwarf wheat mutants, designated je0370 and je0344, using the winter wheat cultivar Jing411 as the wild type (WT). Field experiments revealed that the plant height of these two mutants was significantly lower than that of the WT. In contrast, the thousand-grain weight was significantly higher in je0370 but lower in je0344 compared to the WT. Bulk Segregant Analysis (BSA) based on exome capture sequencing indicated that the gene responsible for height reduction is located on chromosome 4B. Further genetic linkage analysis mapped the dwarf gene to the interval of 29.26-48.61 Mb on chromosome 4B, corresponding to a genetic distance of 10.79 cM. This region encompasses the Rht1 gene; we subsequently sequenced the Rht1 gene in je0370 and je0344 and identified a C-T mutation at position 190 bp, resulting in a truncation of the DELLA domain in both mutants. Further analysis using Cleaved Amplified Polymorphic Sequences (CAPS) markers in F₂ populations demonstrated that plants with homozygous Rht1 mutations exhibited significantly reduced plant height and thousand-grain weight, while heterozygous plants displayed intermediate effects. However, the mutation did not significantly affect spikelet number, effective spike number, or spike length. These findings conclusively demonstrate that the Rht1 mutation is responsible for plant dwarfism and reduced grain weight, without substantial impacts on other yield components. This study provides invaluable insights into the utilization of Rht1 in wheat breeding.

The browning of Thompson seedless grapes during shade-drying significantly hampers the sustainable and healthy development of the industry. This study investigates the browning phenomenon and reactive oxygen species (ROS) dynamics when Thompson seedless grapes, treated with adenosine triphosphate (ATP), 2,4-dinitrophenol (DNP), and water (QS), are dried in the shade. The effects of these treatments on ROS metabolism were analyzed through physiological, biochemical, and proteomic analyses. The findings showed that ATP treatment markedly delayed the increase in browning and reactive oxygen content, maintained high activity levels of ROS scavenging enzymes (superoxide dismutase and peroxidase), reduced malondialdehyde production-a membrane lipid peroxidation product-and preserved cell membrane integrity compared to QS and DNP treatments. Proteomic analysis identified three biological pathways involved in ROS metabolism in Thompson seedless grapes: glutathione metabolism, ascorbic acid, and glyoxalate metabolism, and peroxisomal pathways. Exogenous ATP treatment upregulated the expression of 17 proteins (SOD, APX, GPX, GST, GR), with significant increases in GST2 (D7SKQ2), POD1 (F6H095), SOD3 (D7TI74), and SOD4 (F6HTX9) by 1.707, 1.589, 1.644, and 2.213-fold, respectively. Therefore, ATP treatment maintains ROS scavenging proteins' expression, reduces the accumulation of ROS, maintains a balance in ROS metabolism, maintains the cell membrane stability and suppresses the oxidation of lipids, thus delaying the browning of Thompson seedless grapes. These findings are significant for regulating browning in the shade-drying process of Thompson seedless grapes.

Sucrose is an essential energy substance for tree peony (Paeonia Suffruticosa) floral organ development. However, little is known about the sucrose regulatory network in tree peony. In this study, the promoter sequence of the tree peony sucrose transporter gene PsSUT2 was cloned. Through cis-acting elements analysis and weighted gene co-expression network analysis (WGCNA), 6 transcription factors potentially regulating PsSUT2 were screened. Expression analysis revealed that the 6 transcription factors had similar expression trends with the PsSUT2 in all parts of peony at the full bloom stage. Furthermore, a yeast one-hybrid assay revealed that PsMYB20 and PsMADS9 bind to the PsSUT2 promoter. Dual-luciferase reporter assay demonstrated that PsMYB20 and PsMADS9 could activate PsSUT2 expression. Taken together, our findings suggest that PsMYB20 and PsMADS9 positively regulate PsSUT2, laying the foundation for the construction of a gene network for sucrose regulation in tree peony.

Calcium-dependent protein kinases (CDPKs) are very effective calcium signal decoders due to their unique structure, which mediates substrate-specific [Ca²⁺]_cyt signalling through phosphorylation. However, Ca²⁺-dependence makes it challenging to study CDPKs. This work focused on the effects of the overexpression of native and modified forms of the AtCPK1 gene on the tolerance of tobacco plants to heat and cold. We studied the interaction between the calcium and signalling systems of abscisic acid (ABA) at various temperatures. The hormonal state, stress-induced senescence, and expression of important corresponding genes were investigated. We showed that inactivation of the autoinhibitory domain of the modified constitutively active form of AtCPK1 has a positive effect on resistance not only to long-term cold but also to heat. We showed that the constitutively active form of AtCPK1 under nonstressed conditions activated biosynthesis of ABA, but a decrease in ABA content was detected upon heat exposure. On the basis of our results, we can assume that this effect is achieved through the CPK-dependent activation of salicylic acid (SA) signalling. The obtained data shed light on heat-associated molecular processes and support the possibility of using intradomain modifications of CDPK both for comprehensive study of its functional features and as a bioengineering tool.

To uncover the variation patterns of the nutritional components in sweetpotato storage roots during long-term storage comprehensively, the general nutrients, phytochemicals, and starch properties of nine sweetpotato varieties with different flesh colors were quantified and analyzed by chemical and physical techniques. During the storage, the starch content decreased firstly and then increased, with sugar content the opposite. The crude protein content and the total dietary fiber content both increased continuously. The β-carotene content decreased or kept constant, while the anthocyanin content showed different variation patterns in the three purple-fleshed varieties. The four types of polyphenols and two types of flavonoids showed no obvious content changes during the storage. The amylose contents of all varieties showed various patterns, while the crystallinity was C-type. The proportion of small-sized starch granules reduced, and the combined proportion of medium-sized and large-sized granules increased. New correlations among the nutritional parameters for each variety were revealed for the first time. Principal component analysis indicated that the orange-fleshed varieties were distinguished from other varieties. Finally, the most storage-resistant variety ZZ3 and the suitable variety for each quality trait was selected. This study provides not only theoretical basis for comprehensive understanding of the nutrient's variations in sweetpotato storage roots during long-term storage, but also guidelines for evaluation of nutritional quality of sweetpotato roots during storage and improvement of storage methods.

Apple (Malus domestica Borkh.) seeds exhibit deep embryonic dormancy. Uniform germination of isolated apple embryos is observed after 40-day-long cold stratification of the seeds. Stratification treatment modifies the level of reactive oxygen species (ROS), which are regarded as key regulators of seed dormancy. In this study, axes of embryos isolated from seeds stratified for 7, 14, 21, and 40 days differing in dormancy depth were used. After one week of stratification, the increased polyamine oxidase activity enables ROS generation, which is followed by an upregulation of the NADPH oxidase gene expression. Catalase activity increased after 14 days of stratification, suggesting the requirement to maintain ROS concentrations at an optimal level already in the early phase of dormancy removal. When cold stratification was prolonged, accompanied by a significant increase in ROS level, ROS scavenging by catalase was supported by elevated phenolic compounds content. Then, peroxidase activity was also the highest. As ROS-induced phenylalanine (Phe) oxidation leads to the formation of meta-tyrosine (m-Tyr) - a potentially toxic component, the levels of these amino acids were examined. The fluctuation in m-Tyr content indicates the existence of mechanisms in the tissue for the disposal of this compound. Finally, its presence may be mitigated by an increase in Phe levels. Maintaining oxidised RNA at elevated levels from the 14th day of stratification may be crucial for seed dormancy removal, ensuring translation regulation as metabolism resumes. We concluded that dormancy removal of apple seeds by stratification requires a time-dependent sequence of biochemical events reflecting ROS metabolism alterations.