Plant Molecular Biology最新文献

Self-incompatibility is a fundamental biological mechanism in flowering plants that prevents self-fertilization, thereby promoting outcrossing and enhancing genetic diversity. This complex system has independently evolved across multiple angiosperm lineages and is crucial in maintaining plant reproductive success. Recent research has expanded our understanding of self-incompatibility's molecular basis and uncovered key genes and signaling pathways involved in self-incompatibility responses, such as S-RNase in Solanaceae and PrsS-PrpS in Papaveraceae, as well as the SRK-SCR interaction in Brassicaceae. However, despite significant advances, many aspects of self-incompatibility, such as the interplay between gene duplications, polyploidization, and the evolution of novel self-incompatibility mechanisms, remain underexplored. This review integrates findings from various plant families, including Solanaceae, Rosaceae, Papaveraceae, and Brassicaceae, and discusses the evolutionary dynamics of self-incompatibility systems, highlighting the role of gene duplication, recombination, and translocation events in shaping self-incompatibility diversity. Special emphasis is placed on understanding how modern molecular techniques, such as CRISPR/Cas9 and marker-assisted selection, can be employed to transition self-incompatibility to self-compatibility in economically significant crops. Additionally, the role of epigenetic changes and modifier genes in mediating transitions from self-incompatibility to self-compatibility is addressed, offering insights into how these mechanisms can be leveraged for crop breeding and hybrid seed production. Future research should focus on elucidating the molecular mechanisms underlying self-incompatibility responses, exploring the potential of targeted gene editing to overcome reproductive barriers, and understanding the evolutionary resilience of self-incompatibility systems to environmental changes.

Solanum chacoense is a wild potato species with superior genetic resistance to diseases and pests that has been extensively used for introgression into cultivated potato. One determinant of crossing success between wild and cultivated potato species is the effective ploidy of the parents. However, little is known about whether other, prezygotic level, breeding barriers exist. We hypothesize ovular pollen tube guidance may serve as such a checkpoint. Tests for species-specific pollen tube guidance using semi-in vivo assays suggested a positive correlation between species-specificity and taxonomic distance. RNA-seq of ovules dissected from wild type plants at anthesis (mature ovules) and two days before anthesis (immature ovules), as well as from a frk1 (fertilization-related kinase 1) mutant lacking an embryo sac (ES) identified a list of 284 ES-dependent transcripts highly expressed in mature ovules and poorly expressed in all other samples. Among these are 17 Solanum chacoensecysteine-rich proteins (ScCRPs), considered to be candidates for pollen tube attractants since identified attractants in other species are also CRPs. A group of three cloned and purified ScCRP2 peptides belonging to the DEFL protein family showed moderate levels of in vitro pollen tube attraction activity in functional assays. We conclude that ScCRP2s are good candidates for ovular pollen tube guidance in S. chacoense.

Rice (Oryza sativa) is a crucial staple for more than half of the global population, yet it faces significant pest pressures, notably from the striped stem borer, Chilo suppressalis. This insect deposits eggs on rice surfaces, and their hatched larvae bore into stems, causing substantial yield losses. Whereas the responses of rice to larval feeding are well-documented, less is known about its reaction to C. suppressalis oviposition at the molecular and biochemical levels, despite evidence that insect egg deposition triggers various defence mechanisms in plants. In this study, next-generation RNA sequencing and comprehensive metabolomics were utilised to analyse rice leaves with and without eggs, revealing shifts in gene expression and metabolite synthesis. The effects of egg-deposited rice to oviposition behaviour were also tested. The results indicated 1,350 differentially expressed genes and 234 differential metabolites 24 h after C. suppressalis oviposition. Up-regulated genes included those involved in defence, stress responses, and secondary metabolism. Furthermore, metabolomic studies indicated increased levels of lipids, flavonoids, terpenoids, and phenolic compounds in response to oviposition, mirroring the observed responses against pathogens. Oviposition behavioural test results suggested that C. suppressalis oviposition activity was deterred by egg-laden rice. These findings enhance our understanding of induced defence mechanisms in rice against C. suppressalis at the molecular and biochemical levels, potentially guiding the development of ovicidal substances, insect-resistant rice varieties, and rice-protection strategies.

Climate change presents escalating threats to agricultural productivity and global food security, primarily through increased frequency and intensity of environmental stresses. Without adaptation measures, crop yields are projected to decline by 7% to 23% under the most extreme climate change scenarios. Despite growing awareness, a critical knowledge gap persists in understanding the combined impact of abiotic and biotic stresses on crop resilience. This study examines integrated approaches including the development of drought-tolerant crop varieties and the application of integrated pest management to enhance agricultural systems against climate-induced stresses. These strategies offer the potential to improve yield stability, reduce reliance on chemical inputs, and support the transition toward more sustainable and climate-resilient food systems. The findings aim to guide policymakers and agricultural stakeholders in implementing targeted, science-based interventions to safeguard food security under changing environmental conditions.

Rubber elongation factor (REF) and small rubber particle protein (SRPP) are critical components in the biosynthesis of natural rubber in Hevea species, with both proteins playing significant roles in regulating stress responses. Despite recent advancements in understanding their regulatory mechanisms, a comprehensive analysis of their functional roles, gene evolution, expression patterns, and biological regulation is still needed. This review consolidates current knowledge on REF and SRPP, highlighting their evolutionary history and the influence of environmental factors and hormonal signals on their transcriptional regulation. Additionally, it explores the potential of REF and SRPP in plant breeding, not only for improving rubber-producing plants but also for enhancing stress tolerance in non-rubber-producing species. The review emphasizes the need for further research into the molecular mechanisms driving REF and SRPP function, including their involvement in stress resilience and interactions with other proteins in rubber biosynthesis. By synthesizing the latest findings, this work aims to inform future breeding strategies and genetic engineering efforts, with a particular focus on improving rubber production efficiency and increasing plant resistance to abiotic stresses such as drought and salinity. This review provides valuable insights for optimizing the utilization of REF and SRPP in future crop improvement programs.

Benzoic acid, the simplest aromatic carboxylic acid, is an important building block for a wide range of primary and specialized plant metabolites. In Petunia hybrida, benzoic acid serves as a key precursor of volatile benzenoids, which are responsible for the primary floral scent. However, the enzymes responsible for benzoic acid production in plants have rarely been reported. This study aimed to identify and characterize benzaldehyde dehydrogenases-enzymes that catalyze the oxidation of benzaldehyde to benzoic acid-using a combination of metabolite analysis and transcriptomic approaches. We identified two petunia benzaldehyde dehydrogenases, PhBALDH-1 and PhBALDH-2, with apparent K_m values of 93 and 51 μM for benzaldehyde, respectively. While PhBALDH-2 exhibited a strong preference for NAD⁺ as a cofactor, PhBALDH-1 was capable of utilizing both NAD⁺ and NADP⁺. In vitro mutagenesis experiments demonstrated that substituting a single amino acid markedly affected the cofactor specificity of the PhBALDH-1 enzyme. Gene expression analysis during petunia flower development suggests that both PhBALDH-1 and PhBALDH-2 are likely involved in regulating volatile benzenoid biosynthesis in petunia flowers. Our findings provide functional insights into the biosynthesis of benzoic acid and its regulation in P. hybrida.

BEL1-LIKE HOMEODOMAIN (BLH/BELL) family transcription factors play important roles in the response of plants to environmental stress. In this study, we found that the BLH/BELL transcription factor SlBEL2 affects drought tolerance in tomato plants, as SlBEL2-knockout (KO-SlBEL2) tomato plants showed enhanced drought tolerance, whereas SlBEL2-overexpression (OE-SlBEL2) tomato plants displayed impaired drought tolerance. Further research demonstrated that SlBEL2 negatively regulates drought tolerance in tomato plants by suppressing the expression of a number of genes that respond to drought. In addition, a RING E3 ligase, SlRGLG2, interacts with SlBEL2 and promotes ubiquitination degradation of SlBEL2, thus affecting the stability of the SlBEL2 protein, which in turn positively regulates drought tolerance in tomato plants. In summary, the SlRGLG2-SlBEL2 module regulates drought tolerance in tomato plants, and the aforementioned findings offer a novel viewpoint on the tomato plant's drought tolerance regulatory network.

The preservation of recalcitrant seeds is crucial for sustainable forest management and biodiversity conservation, particularly for economically important species like Quercus acutissima. However, these seeds pose serious challenges for ex situ conservation due to their high sensitivity to desiccation. This study employed integrated physiological, cytological, and proteomic approaches to systematically reveal the characteristics of viability loss during desiccation of Q. acutissima seeds. The results showed that fresh seeds had an initial moisture content of 38.8% (IM) with a germination percentage of 99%, while the semi-lethal (SLM) and lethal moisture (LM) contents were 26.8% and 14.8%, respectively. Desiccation caused cell wall collapse, membrane system rupture, and cytoplasmic degradation, while physiological and proteomic results revealed distinct responses during different desiccation stages. In the early stages, downregulation of iron superoxide dismutase indicated antioxidant system impairment, while lipoxygenase-mediated membrane lipid peroxidation triggered reactive oxygen species and malondialdehyde accumulation. During the deep desiccation stages (LM), we observed active energy metabolism with isocitrate dehydrogenase [NADP] upregulation. Additionally, the downregulation of phospholipase D and acyl-CoA synthetase may promote abnormal accumulation of free fatty acids; these factors collectively exacerbated membrane system disintegration. Furthermore, the glutathione-ascorbic acid cycle failed at later stages, translation mechanisms were imbalanced (ribosomal protein upregulation and tRNA synthetase downregulation), programmed cell death -related proteins were upregulated, while protective protein systems (insufficient late embryogenesis abundant expression and delayed small heat shock protein response) failed to effectively mitigate damage. The results suggest that the desiccation sensitivity of Q. acutissima seeds stems from a multi-cascade reaction involving oxidative damage, membrane system collapse, translation dysregulation, and programmed cell death. This study provides a theoretical basis for optimizing recalcitrant seed preservation strategies: comprehensive approaches should include antioxidant protection, membrane stabilization techniques, and metabolic regulation to holistically address multi-system damage during desiccation.

Gene delivery systems are essential for investigating gene regulation mechanisms and enhancing the genetic improvement of functional traits in plants. However, fewer than 0.1% of higher plant species on Earth can be genetically modified. Even for these species, the genetic modification process relies on complex tissue culture methods, which are time-consuming, costly, and often require specialized technical skills. Additionally, the efficiency of genetic modification is extremely low in some species. Notably, over the past five years, significant progress has been made in establishing non-tissue culture genetic modification systems. This advancement effectively resolved a series of previously mentioned challenges and innovated in biotechnology for the improvement of many valuable plant species. This review summarizes the research advancements in non-tissue culture genetic modification technologies and presents examples of successful species modified using various methods, including fast-treated Agrobacterium co-culture (Fast-TrACC), cut-dip-budding (CDB), particle bombardment, and nano-mediated delivery systems. Additionally, we propose a working guideline to classify, analyze, evaluate, and select non-tissue culture genetic modification systems for plant species of interest. Our review also discusses the potential for enhancing plant regeneration capacity, improving genetic modification efficiency, and the future application prospects for plant improvement.