Plant Molecular Biology最新文献

Enhancing drought resilience in crops has become a critical challenge in the face of global climate change, which is exacerbating the frequency and severity of drought events. This review explores mechanistic approaches aimed to improve crop drought tolerance, focusing on physiological, biochemical, and molecular mechanisms. We examine the key molecular pathways involved in drought stress responses, including the Mitogen-Activated Protein Kinase (MAPKs) signaling pathway, hormonal regulation, transcriptional control, and post-translational modifications such as ubiquitination-mediated protein degradation, and plant-microbe interaction. The review also delves into the mechanisms of drought stress tolerance, including drought escape, avoidance, and tolerance. It highlights significant traits contributing to drought resilience, such as stomatal regulation and root architecture. Furthermore, we discuss genomics and breeding approaches, including quantitative trait loci (QTL) mapping, marker-assisted selection (MAS), and cutting-edge CRISPR-Cas-based genome editing technologies. These advanced techniques, such as base editing, prime editing, and multiplexing, transform crop improvement strategies by facilitating precise and efficient modifications for enhanced drought resilience, with the success stories in crops such as rice, maize, wheat, and others. Integrating these mechanistic and technological approaches offers promising avenues for developing drought-resilient crops, ensuring food security under increasingly unpredictable climate conditions.

Geminiviruses constitute a diverse group of plant viruses with small, circular single-stranded DNA genomes. While most geminiviruses possess monopartite genomes, the genus Begomovirus uniquely includes both monopartite and bipartite members. The evolutionary origin of the second component of begomovirus (DNA-B) has been a subject of considerable debate. Two primary hypotheses propose that DNA-B originated from a modified monopartite genome or through the capture of a satellite DNA. Recent discoveries of unclassified bipartite geminiviruses call for a reevaluation of these hypotheses. To address this, we investigated the evolutionary history of the begomovirus nuclear shuttle protein (NSP) through homolog searches, comparative genomics, and structural protein analyses. Our findings unambiguously demonstrated that NSP is homologous to the coat protein (CP) but originated from a CP encoded by an ancient geminivirus lineage, distinct from begomoviruses. This ancient lineage is represented by bipartite viruses integrated into plant genomes of the genus Rhododendron. These results challenge the prevailing paradigm regarding the evolutionary origin of NSP and offer new insights into the evolution of begomovirus genome architecture.

Pyrophosphate (PPi) is an important chemical raw material; however, little research has focus on the effects of exogenous PPi on plant growth, especially under salt stress condition. This study investigated the impact of sodium pyrophosphate (Na-PPi) on the growth of Arabidopsis under 0 mM and 50 mM NaCl conditions. The results showed that 1 mM Na-PPi significantly inhibited the growth of Arabidopsis seedlings in 0.5 MS medium and exacerbated the growth suppression caused by NaCl stress. Na-PPi significantly increased the accumulation of compatible osmolytes in Arabidopsis under NaCl treatment. Additionally, under normal growth condition, Na-PPi treatment significantly reduced the levels of ROS in Arabidopsis; however, this trend was reversed under salt stress condition. Meanwhile, Na-PPi was found to significantly enhance the activity of antioxidant enzymes under both normal and salt stress conditions. Under salt stress, Na-PPi induces the upregulation of genes related to oxidative stress and salt/osmotic stress (such as marker for oxidative stress response protein and OSM34). Moreover, we discovered that Na-PPi significantly downregulates the expression of HAK5, which may account for the significantly decrease in K⁺ content of Arabidopsis seedlings. Intriguingly, genetic evidence shows that SOS proteins play crucial role in the adaptation of Arabidopsis to NaCl + Na-PPi stress. These findings shed light on the role of PPi in plant growth and stress responses, which contributes to the appropriate management and disposal of PPi in practice.

Climate change and global warming drastically alter ecosystems, intensifying extreme weather events such as heavy rainfall and glacier melting, leading to increased soil flooding and threatening agriculture. Waterlogging, a direct consequence of prolonged soil saturation, severely affects plant growth by causing hypoxia, impaired nutrient uptake, photosynthesis inhibition, energy depletion, and microbiome disturbances, ultimately leading to plant mortality. Despite research progress in mitigating waterlogging stress, the molecular mechanisms underlying plant perception and their subsequent adaptive responses remain largely unclear. Recent advancements in molecular, biochemical, and multi-omics technologies have enabled significant progress in understanding the molecular mechanisms of plant responses to stress conditions. In this review, we highlight the metabolic pathways and key genes that could be targeted to enhance waterlogging tolerance and discuss how advanced techniques can be implemented to understand waterlogging responses and develop resistant cultivars. We review molecular insights into how ethylene and hypoxia signaling pathways trigger waterlogging responses and highlight key factors involved in energy metabolism and phytohormone signaling pathways, along with possible directions for further study.

Extension of the light period causes photoperiod stress in Arabidopsis thaliana. The photoperiod stress phenotype is characterized by an induction of stress and cell death marker genes, the formation of reactive oxygen species (ROS) and enhanced formation of jasmonates during the night following the extended light period. Previously, experiments had shown that the jar1-1 mutant, carrying a point mutation in the jasmonoyl-isoleucine (JA-Ile) biosynthesis gene JAR1, showed a strongly reduced stress phenotype suggesting that JA-Ile is required for the stress response. Here, we have analyzed the roles of JA-Ile and JAR1 in more detail. While jar1-1 reduced the photoperiod stress phenotype indicating that JAR1 is required for the response to photoperiod stress, mutation of the ALLENE OXIDE SYNTHETASE (AOS) jasmonate biosynthesis gene did not rescue the stress phenotype. Further, analysis of jasmonate signaling mutants did not indicate their broad resistance to photoperiod stress. Unexpectedly, other JAR1 mutant alleles like jar1-11 and fin219-2 did not alleviate the photoperiod stress phenotype. Genetic analysis revealed that a recessive unlinked second-site mutation in the jar1-1 mutant background is responsible for the suppression of the photoperiod stress response. Taken together, these results suggest that JA-Ile is less important for the response to photoperiod stress than indicated by previous results.

Thionins are a class of small, cationic plant peptides with well-documented antimicrobial activity. They play a crucial role in plant defense by destroying the cell membranes of pathogens and triggering immune responses. Due to their broad spectrum of activity and natural origin, thionins are increasingly considered eco-friendly alternatives to conventional chemical pesticides in integrated pest management strategies. This review examines the various biological functions of thionins, their molecular mechanisms of action, and their potential applications in agriculture. Particular attention is paid to current limitations, including peptide stability, specificity, regulatory challenges, and innovative approaches to overcome these, such as encapsulation technologies and targeted delivery systems. In addition, the role of thionins in promoting sustainable agriculture and improving the climate resilience of crops will be discussed. Thionins support ecosystem health and food security by reducing dependence on synthetic agrochemicals. Continued research and interdisciplinary collaboration are essential to close current knowledge gaps and facilitate the path to practical implementation. With strategic innovation, thionins can serve as key tools in the development of robust crop protection systems suitable for a changing climate.

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.