Plant Physiology and Biochemistry最新文献

Tomato, belonging to the nightshade family, is globally considered as a model system for classical and molecular genetics, genomics, and reproductive developmental studies. In the current scenario of climate change, hybrid development is among the crucial elements in the genetic improvement of crop plants. The phenomenon of male sterility is a viable approach for ensuring hybrid seed purity and reducing the cost of hybrid seed production. This review aims to shed light on the use of neoteric genomics and genome editing tools in understanding the genetics and molecular regulation of male sterility in tomato. Plant male gametophyte development is highly susceptible to environmental stress. Abnormalities at any stage of male reproductive development, such as premature or delayed tapetal cell degradation triggered by oxidative stress and programmed cell death (PCD) leads to male sterility in tomato. In tomato, more than 55 sporogenous, structural, and functional male sterile mutants, which are mainly under the control of recessive nuclear genes, have been reported. Recently, the role of open reading frames (ORFs) in governing cytoplasmic male sterility in tomato has also been documented. This review highlights the genetic and genomic progress in the investigation of underlying molecular pathways and practical application of potential male sterile mutants in tomato breeding. The applications and future prospects of genome engineering with CRISPR/Cas9 and mitoTALEN in the generation of novel male sterile systems to expedite tomato breeding is discussed.

Gibberellin (GA) is one of the crucial plant hormones involved in fruit ripening regulation. GASA genes, which respond to GA and encode cysteine-rich peptides, are prevalent in plants. While the GASA gene family has been identified in various plants, its role in persimmon fruit ripening remains unclear. In this study, the GASA genes of persimmon were identified and analyzed. We found that gibberellin treatment suppresses the expression of the DkGASA4. Additionally, through dual-luciferase and yeast two-hybrid assays, we discovered that DkGASA4 interacts with DkNAC9 to synergistically activate the transcription of the cell wall degradation gene DkEGase1. This study highlights the significant regulatory function of DkGASA4 in persimmon fruit ripening and softening.

Cadmium (Cd) concentrations in cacao beans from Latin America often exceed limits for trading. A better understanding of the mechanisms of Cd accumulation in Theobroma cacao L. trees is necessary to advance mitigation strategies. Recent studies on a high Cd accumulating cultivar of cacao revealed that calcium oxalate (CaOx) crystals were involved in Cd accumulation in the branches. The purpose of this study was to quantify soluble and crystalline oxalate in cacao compartments, to characterize their morphology and distribution in the tissues, and to evaluate the relationship between CaOx and Cd total concentrations in each plant compartment. Two representative cultivars from Latin America (CCN-51 and Nacional) were studied. CCN-51 trees grew on soils with low and high total Cd contents (0.120 ± 0.002 and 2.59 ± 0.48 mg kg⁻¹, respectively), and Nacional trees grew on soils with low Cd content (0.188 ± 0.005 mg kg⁻¹). Oxalate was present in all organs of the two cultivars. In mature leaves, oxalate content exceeded the limit of 5% per dry weight used to define extreme oxalate accumulators. The crystalline form predominated in branches and mature leaves (82-92%), whereas the soluble form predominated in nibs (67-82%). Calcium oxalate crystal size varied from <1 μm (generally agglomerated as crystal sand) to a few tens of μm (faceted crystals). Log CaOx and Cd concentrations were positively correlated in branches (R² = 0.77, p = 0.002) and roots (R² = 0.71, p = 0.005), whereas in nibs, the oxalate content was almost constant among conditions. The possible roles of CaOx crystals in the cacao plant, including Ca regulation, protection against herbivory, tissue stiffening and Cd detoxification are discussed.

Conifers of the genus Taxus are environmentally friendly plants with significant medicinal and ecological value, contributing to the enhancement of urban living environments. Paclitaxel, a compound found in Taxus, has garnered particular research interest owing to its potent anti-cancer effects. However, traditional methods of extracting paclitaxel from Taxus are not only inefficient, but also destructive and unsustainable, posing the major risk of Taxus extinction. To address this, sustainable production using modern biotechnology is crucial for the mass production of paclitaxel. Therefore, this review revisits the potential of Taxus and sustainable paclitaxel production in the context of urban agriculture. It provides a comprehensive review of widespread research efforts targeting efficient and cost-effective paclitaxel biosynthesis. We also discuss a set of innovative strategies for paclitaxel biosynthesis and suggest approaches for its industrial production based on Taxus cell-based approaches.

Cadmium (Cd) contamination greatly hinders plant productivity. Nanotechnology offers a promising solution for Cd phytotoxicity. The novelty of this study lies in the limited research on the effects of nanoiron (Fe₃O₄NPs) in regulating Cd toxicity in oilseed crops. This study examined how Fe₃O₄NPs regulated the Cd-exposure in B. napus. Foliar spray of 10 mg L^-1 Fe₃O₄NPs was applied to 50 μM Cd-stressed B. napus seedlings via leaf exposure in hydroponic system. Under Cd stress, Fe₃O₄NPs decreased the Cd-accumulation (25-37%) due to adsorption followed by more root Cd-immobilization, and increased the plant height (23-31%) and biomass (17-24%). These findings were directly correlated with better photosynthetic activity (chlorophylls, gas exchanges and photosynthetic efficiency), leaf stomata opening and nutrients accumulation (20-29%). Subcellular localization revealed that Fe₃O₄NPs enhanced the binding capacity of cell wall for Cd to hinder its entry into cell organalles and facilitated vacoular sequestration. Additionally, Fe₃O₄NPs decreased the oxidative stress (21-33%) and peroxidation of lipids (24-31%) by regulating the genes-associated to superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, glutathione reductase, reduced glutathione, phytochelation, chlorophyll synthesis and Cd-transporters. Fe₃O₄NPs protected plant roots from Cd-induced cell structural damages and cell death. Among studied parameters, ZD 635 exhibited greater tolerance to Cd stress when compared to ZD 622 cultivar. Findings revealed that Fe₃O₄NPs effectively mitigate Cd toxicity by improving the photosynthesis, antioxidant defense mechanisms, cellular protection, nutrients accumulation and limiting Cd accumulation. This research offers a benchmark for the practical applicability of Fe₃O₄NPs to enhance the quality of canola production in Cd-contaminated soils.

Lagerstroemia excelsa is a unique plant species from China, holds a significant aesthetic and economic value, and plays a crucial role in landscape architecture and horticulture. Thus far, there is little genetic and genomic information available about this species, which limits its use in development of new cultivars. In this study, a high-quality genome map of L. excelsa was obtained via whole-genome sequencing. Results showed that its genome size is about 330.4 Mb and a scaffold mapping rate is approximately 97.20%, resulting in 24 pseudochromosomes. L. excelsa might have undergone a recent whole-genome triplication event and diverged from the pomegranate about 32.3 million years ago (MYA). Subsequently, the divergence time between L. indica and L. excelsa was around 5.9 MYA. The transcriptomic and metabolomic analyses of L. excelsa and L. indica indicated that the chalcone synthase pathway may play a key role in regulating flower color differentiation between the two species. Additionally, a transcription factor LeMYB103 may be involved in regulating anthocyanin synthesis by interacting with LeMYB66, resulting in the accumulation of anthocyanins in the stem bark. This study is the first step toward genomic analysis of L. excelsa, which may provide a foundation for further molecular investigation of this species and offer valuable insights into the molecular mechanisms underlying the flower and stem bark colors in L. excelsa, two important ornamental traits in Lagerstroemia breeding.

Plant height is a key trait that significantly influences plant architecture, disease resistance, adaptability to mechanical cultivation, and overall economic yield. Galactinol synthase (GolS) is a crucial enzyme involved in the biosynthesis of raffinose family oligosaccharides (RFOs). It plays a significant role in carbohydrate transport and storage, combating abiotic and biotic stresses, and regulating plant growth and development. The present study employed CRISPR/Cas9 gene-editing technology to create the gols4 mutant in tomato (Solanum lycopersicum), which exhibits a semi-dwarf phenotype. Results showed that glucose, sucrose, myo-inositol, galactinol, and raffinose levels were significantly reduced in the slgols4 mutant, impairing material transport and affecting the balance of soluble carbohydrates. Integration of transcriptomics and metabolomics data indicated not only a decrease in the expression of synthesis genes related to phenylpropanoid biosynthesis but also a significant reduction in the content of lignin and flavonoids, which are byproducts of phenylpropanoid metabolism. This may be a key factor contributing to dwarfism. Overall, these findings provide evidence for the role of SlGolS4 in regulating sugar metabolism and phenylpropanoid metabolism, offering new insights into tomato dwarfing cultivation and germplasm resources.

Lacquer tree (Toxicodendron vernicifluum) is an important economic crop and is rich in flavonoids. ACC (1-aminocyclopropane-1-carboxylic acid) is the precursor to ethylene. ACC treatment can induce physiological and biochemical responses in plants. In this study, flavonoids in the leaves of Toxicodendron vernicifluum, treated with ACC at different time points, were identified and analyzed. A total of 83 flavonoids were identified, including 38 flavonoids and 45 flavonoid glycosides. Among these, 48 flavonoids were first reported in T. vernicifluum. The total flavonoid content significantly increased following ACC treatment, although the accumulation patterns of individual flavonoids varied. Flavonoids with similar structure or glycosylation/acetylation modifications exhibited a positive correlation in their content changes in T. vernicifluum leaves under ACC treatment. Transcriptome sequencing was conducted on control and 3-days ACC-treated leaves, revealing an upregulation in the expression of genes related to flavonoids biosynthesis, such as PAL, CCR, CHS, MYB and ERF encoding genes. We hypothesized that ACC regulated flavonoids biosynthesis by activating ERF and MYB transcription factors in the ethylene signaling pathway. This study provided evidence for the regulation of flavonoids biosynthesis in lacquer trees through ACC treatment.

Plants are often exposed to combined stress, e.g. heat and cadmium (Cd) stress under natural conditions. Nitrogen (N) fertilizer is usually applied in excess, even though it is an essential nutrition for plants. We aimed to clarify the effects of elevated temperature, Cd stress, reduced N fertilizer and their interaction on leaf physiology and metabolism of anthesis tomato plants. Tomato plants at anthesis stage were subjected to unique combinations of elevated temperature (34 °C/30 °C), Cd stress (0.1 mM CdCl₂) and half N (N = 95 ppm) treatment. The elevated temperature generally decreased leaf intracellular CO₂ concentration and stomatal conductance, but increased transpiration rate with no significant changes in net photosynthetic rate, as compared with control. The plants under elevated temperature exhibited higher chlorophyll content as well as lower anthocyanin than under control temperature. The temperature had significant impacts on open flowers in the 1st inflorescence counting from bottom, open flower percentage in the 1st inflorescence, fresh and dry weight of flowers. Temperature played a predominant role in the changes of metabolites among the three factors based on metabolome. The Cd stress and reduced N supply also affected leaf metabolites of tomato plants, even though the effects on metabolites and physiology were less than that of elevated temperature. Trend analysis of the metabolites showed eight types in tomatoes under eight treatments. Biosynthesis of secondary metabolites, phenylpropanoid biosynthesis, linoleic acid metabolism and ABC transporters pathways positively responded to the elevated temperature. Moreover, there were significant interactions between the three factors (temperature, CdCl₂ and N) on tomato physiological and morphological parameters. We concluded that the physiological and metabolic responses of tomato plants were more pronounced to the elevated temperatures as compared with cadmium stress and reduced nitrogen fertilizer. This study can support the understanding of complex regulatory mechanisms in plants responding to multiple environmental changes due to climate change, management practice and environmental pollution.

Increasing nitrogen use efficiency (NUE) remains a crucial topic in contemporary agriculture. Inoculation with endophytic diazotrophic bacteria offers a potential solution, but the results vary with the N-fertilization regime. Here, we examined the efficacy of inoculation with Herbaspirillum seropedicae strain HRC54 in enhancing NUE and promoting the growth of Marandu palisadegrass with varying levels of N-urea (0, 25, 50, and 100 mg N kg soil⁻¹). We evaluated NUE indicators and conducted complementary analyses covering biochemical, physiological, nutritional and growth-related parameters after cultivating the plants within a greenhouse environment and maintaining controlled conditions of temperature and humidity. Growth promotion was evident in inoculated plants receiving up to 50 mg N kg soil^-1, with enhanced root growth orchestrating the improvement in NUE. Inoculation also improved the nutritional status of the plants (increased N and P accumulation and N balance index) and increased photosynthesis-related parameters, resulting in increased biomass yield. Insufficient N supply led to oxidative stress (overproduction of H₂O₂ and MDA), which was associated with a reduction in photosystem II efficiency, chlorophyll concentration, and soluble proteins, but only in plants that did not receive microbial inoculation. Conversely, a high N supply (100 mg N kg soil^-1) combined with H. seropedicae had no synergistic effect, as NUE and the associated benefits did not improve. Therefore, inoculation with H. seropedicae is effective at increasing NUE when combined with moderate N rates. These findings support a more rational use of N fertilizers to optimize inoculation benefits and enhance NUE in tropical forage crops.