Journal of Plant Research最新文献

Barley (Hordeum vulgare L.) is an important cereal crop used in animal feed, beer brewing, and food production. Waterlogging stress is one of the prominent abiotic stresses that has a significant impact on the yield and quality of barley. Seed germination plays a critical role in the establishment of seedlings and is significantly impacted by the presence of waterlogging stress. However, there is a limited understanding of the regulatory mechanisms of gene expression and metabolic processes in barley during the germination stage under waterlogging stress. This study aimed to investigate the metabolome and transcriptome responses in germinating barley seeds under waterlogging stress. The findings of the study revealed that waterlogging stress sharply decreased seed germination rate and seedling growth. The tolerant genotype (LLZDM) exhibited higher levels of antioxidase activities and lower malondialdehyde (MDA) content in comparison to the sensitive genotype (NN). In addition, waterlogging induced 86 and 85 differentially expressed metabolites (DEMs) in LLZDM and NN, respectively. Concurrently, transcriptome analysis identified 1776 and 839 differentially expressed genes (DEGs) in LLZDM and NN, respectively. Notably, the expression of genes associated with redox reactions, hormone regulation, and other biological processes were altered in response to waterlogging stress. Furthermore, the integrated transcriptomic and metabolomic analyses revealed that the DEGs and DEMs implicated in mitigating waterlogging stress primarily pertained to the regulation of pyruvate metabolism and flavonoid biosynthesis. Moreover, waterlogging might promote flavonoid biosynthesis by regulating 15 flavonoid-related genes and 10 metabolites. The present research provides deeper insights into the overall understanding of waterlogging-tolerant mechanisms in barley during the germination process.

Since photosynthesis is highly sensitive to salinity stress, remote sensing of photosynthetic status is useful for detecting salinity stress during the selection and breeding of salinity-tolerant plants. To do so, photochemical reflectance index (PRI) is a potential measure to detect conversion of the xanthophyll cycle in photosystem II. Raphanus sativus var. raphanistroides is a wild radish species closely related to domesticated radish, and is distributed throughout the coastal regions of Japan, where it is thought to be salt tolerant. In this study, we raised wild and domesticated radishes under various salt conditions and assessed growth, photosynthetic status, and PRI. When grown at mild salt stress (50 mM NaCl), wild radish leaves showed photosynthetic activity levels comparable to control plants, whereas the photosynthetic activity of domesticated radish was suppressed. This result suggests that wild radishes are more salt-tolerant than domesticated radishes. Although photosynthetic rate and the photochemical quantum yield were significantly correlated with PRI in both species, the PRI resolution was insufficient to distinguish differences in salt tolerance between wild and domesticated radish. Wild radish had a lower maximum quantum yield (Fv/Fm) when grown under moderate salt stress (200 mM NaCl), suggesting chronic photoinhibition. The relationship between non-photochemical quenching (NPQ) and PRI was significant when leaves with chronic photoinhibition were eliminated but this relationship was not significant when they were included. In contrast, the relationship between photosynthesis and PRI was significant regardless of whether leaves displayed chronic photoinhibition or not. We conclude that PRI is useful to detect relatively large reductions in photosynthetic rate under salinity stress, and that care should be taken to evaluate NPQ from PRI.

Calotropis procera (Aiton) W.T. Aiton is a medicinal plant belonging to the family Apocynaceae as a core source of natural cardenolides. Cardiac glycosides (CGs) are steroid derivatives reported to have the ability to regulate cancer cell survival and death through multiple signaling pathways. Earlier stage-specific and wound-responsive accumulation of CGs and their genin units have already been reported. Recent cumulative evidences have implicated stress and defense response signaling in the production of secondary metabolite in plants. In this report, seasonal accumulation of CGs and its genin units have been explored along with their profiling under control vs stress conditions with a significant accumulation using LC-MS/MS. The study showed that Calotropis procera plants efficiently accumulate CGs and genin units in both winter and summer beside rainy season, as well as under thermal and salinity stress. Among the three cardenolides, the calotropagenin was accumulated more than coroglaucigenin and uzarigenin whereas CGs like calotropin, frugoside, uscharidin, uscharin, and asclepin were significantly accumulated in response to heat, cold and NaCl. Comparatively for hormonal treatments like methyl jasmonate and salicylic acid, targeted metabsolites showed upto twofold accumulation. Gene expression analysis of CG biosynthetic genes also validated the accumulation pattern of the targeted metabolite. This targeted metabolites accumulation enhances plant tolerance to adverse conditions. Gene expression analysis supports this strategy, emphasizing the plant's effective stress management. These findings significantly contribute to our understanding of how plants adapt to stress through the accumulation of metabolites, thereby enhancing their tolerance to challenging environmental conditions.

The oxidative damage induced by abiotic stress factors such as salinity, drought, extreme temperatures, heavy metals, pollution, and high irradiance has been studied in Arabidopsis thaliana. Ultra-weak photon emission (UPE) is presented as a signature reflecting the extent of the oxidation process and/or damage. It can be used to predict the physiological state and general health of plants. This study presents an overview of a potential research platform where the technique can be applied. The results presented can aid in providing invaluable information for developing strategies to mitigate abiotic stress in crops by improving plant breeding programs with a focus on enhancing tolerance. This study evaluates the applicability of charged couple device (CCD) imaging in evaluating plant stress and degree of damage and to discuss the advantages and limitations of the claimed non-invasive label-free tool.

Analysis of the sex expression in 10 'Lemon' (mmff) cucumber plants (Cucumis sativus L.), known to be andromonoecious, revealed that 3 plants produced female flowers with short ovaries, resembling bisexual flowers, after producing male and bisexual flowers. To investigate the heredity pattern governing these aberrant female flowers with short ovaries, F₁ hybrid plants (MmFf) were generated through a cross between 'Dokanari-sennari' (MMFF) and 'Lemon' (mmff), and #4 (mmff) and #45 (mmFF) were meticulously selected from a pool of 45 F₂ segregants. Analysis of the sex expression in both 10 F₅ plants (mmff) derived from the #4 (mmff) and 10 F₄ plants (mmFF) derived from the #45 (mmFF) revealed that 8-9 plants produced female flowers with short ovaries after producing male and bisexual flowers. Notably, no female flowers with short ovaries were produced in the plants carrying the M gene, such as 'Dokanari-sennari' (MMFF), 8 F₁ hybrid plants (MmFf), and the 29 F₂ segregants (M-F-,M-ff). Thus, female flowers with short ovaries may be produced in some 'Lemon' (mmff) cucumber plants and their progeny, particularly those carrying the mm genotype (CS-ACS2 genes with c.97G > T mutations), after the production of male and bisexual flowers. However, no clear genetic rules governing the occurrence of these female flowers with short ovaries were observed. This is the first report on trimonoecious cucumber plants displaying male flowers, bisexual flowers with short ovaries, and female flowers with short ovaries, all on the same plant, under the influence of the mm genotype (CS-ACS2 genes with c.97G > T mutations).

Plants defend themselves against herbivores by recognizing herbivore-derived elicitors and activating intracellular signaling. In Arabidopsis, the receptor-like kinase HAK1 recognizes the poly-saccharide elicitor (FrA) from Spodoptera litura larvae, leading to the expression of defense-related genes such as PDF1.2. During this process, the cytoplasmic kinase CRK2 phosphorylates PBL27, triggers the ERF13 expression via ethylene signaling and subsequently leads to PDF1.2 expression. Herein, we investigated four cytoplasmic kinases from the same receptor-like cytoplasmic kinase (RLCK) VII family as PBL27 that interacts with CRK2. Among them, PBL11, like PBL27, is phosphorylated by CRK2 and induces PDF1.2 expression but does not affect ERF13 expression. The weight gain of S. litura larvae on PBL11-deficient mutant plants was only slightly higher than that of wild-type plants, suggesting that PBL11 may function as a minor RLCK that supports the defense response.

In the Malveae tribe (Malvaceae), the axis supporting the flower has a joint at the upper third. This axis can be considered as an articulated pedicel, peduncle, peduncle-pedicel, or anthopodium. Such disparity in terminology reveals a duality in interpretation since this structure is classified as part of the inflorescence or part of the flower. In an effort to reach a consensus, this study aims to evaluate axes supporting the flowers of species from the Malveae tribe through ontogenetic, morphological, and histochemical analyses, using light microscopy and scanning electron microscopy. Ontogenetic analyses indicated that the axis supporting the flower is an articulated pedicel, which is divided into proximal and distal parts owing to the presence of the constriction (joint). Simultaneously, the articulated pedicel arises from the floral meristem, along with the establishment of the calyx and androecium. As development progresses, we observed frequent abscissions of the floral bud, along with the distal portion of the pedicel, at the joint. After this, the remaining proximal portion of the pedicel becomes secretory, as an extrafloral nectary, often foraged by ants of the genus Wasmannia. Thus, this ontogenetic analysis of the articulated pedicel helps in understanding its functionality and morphological variability, highlighting the importance of standardized terminology since it would lead to conceptual clarity in different studies. Additionally, this study, for the first time, reveals the presence of extrafloral nectaries on articulated pedicels in Malveae, a previously undocumented feature in Malveae and Malvaceae.

Various environmental conditions influence the characteristics of plant communities within wetlands. Although the influence of key environmental factors on plant community traits within specific types of wetland ecosystems has been studied extensively, how they regulate plant communities across marsh wetland types remains poorly understood. We examined how environmental conditions influence plant communities in marsh wetlands along the lower Tumen River in northeastern China. We collected and analyzed data on the plant community characteristics (species, height, and coverage), soil physicochemical properties (organic carbon, inorganic nitrogen, and sulfur), and climatic and topographic factors (temperature, precipitation, and elevation) of 56 distinct marsh plots (29 herbaceous, 14 shrub, and 13 forested marshes) to understand how these variables correlate with plant community characteristics across marsh types. The wetland plant diversity varied, with the lowest, intermediate, and highest diversity occurring in herbaceous, shrub, and forested marshes, respectively. Climate, topography, and soil properties had crucial influences on plant diversity and biomass. Structural equation modeling showed that, in herbaceous marshes, plant biomass was primarily determined by soil and plant diversity, with climate exerting an indirect effect. In shrub marshes, soil, climate, and plant diversity directly influenced biomass. In forest marshes, soil and plant diversity directly affected biomass, whereas climate and topography had indirect effects. These findings highlight the complex interactions among environmental factors across marsh ecosystems and their influence mechanisms on biomass, aiding in formulating effective conservation and restoration strategies for marsh wetland ecosystems.