Plant Molecular Biology最新文献

Zanthoxylum armatum DC. fruit is a traditional spicy condiment and medicinal herb, and the prickly ash industry has developed into a pillar industry for specialty agricultural products in many regions of China. As one of the main components of Z. armatum, isoquinoline alkaloids have good biological activity and play an important role in the formation of flavor quality. In this study, we investigated the metabolites and genes involved in the biosynthesis of isoquinoline alkaloids in Z. armatum fruits during three developmental periods. A total of 1167 metabolites and 5204 differentially expressed genes were detected by combining metabolome, SMRT sequencing and Illumina sequencing. The annotation results of KEGG database showed that four metabolites (levodopa, dopamine, tyramine, and magnoflorine) and eight differentially expressed genes were involved in the biosynthesis of isoquinoline alkaloids in Z. armatum fruits. Specifically, metabolites Dopamine and Tyramine decreased with the development of Z. armatum, and the expression of the genes related to their regulation, Zardc00988 and Zardc23209, showed the same trend. This study contributes to our understanding of the biosynthesis and accumulation of Z. armatum isoquinoline alkaloids and provides a reference for the development of the medicinal value of Z. armatum.

The fundamental mechanism of cellulose synthesis is widely conserved across Kingdoms and depends on cellulose synthases, which are processive, dual-function, family 2 glycosyltransferases (GT-2). These enzymes polymerize glucose on the cytoplasmic side of the plasma membrane and export the glucan chain to the cell surface through an integral transmembrane (TM) channel. Structural studies of active plant cellulose synthases (CESAs) have revealed interactions between the nascent glucan chain and the side chains of polar, charged, and aromatic amino acid residues that line the TM channel. However, the functional consequences of modifying these side chains have not been tested in vivo in CESAs or other processive GT-2s. To test this, we used an established in vivo assay based on genetic complementation of CESA5 in the moss, Physcomitrium patens. For accurate prediction of glucan-interacting amino acid residues, we generated a complete homotrimeric molecular model of PpCESA5 using a combination of homology and de novo modeling. All-atom molecular dynamics-based analyses of contact metrics and interaction energy identified 23 amino acid residues with high propensity to interact with the nascent glucan chain within the TM channel or on the apoplastic surface of PpCESA5. Mutating any one of 18 of these amino acid residues to alanine, thereby removing their side chains, abolished or impaired CESA function, with the strongest effects observed upon the loss of charged amino acid side chains. This provides direct evidence to support the hypothesis that multiple amino acid residues collectively maintain a smooth energy landscape within the TM channel to facilitate glucan translocation.

Genome editing tools have revolutionized plant biology research offering unparalleled applications for genome manipulation and trait improvement in crops. Adopting such advanced biotechnological tools is inevitable to meet increasing global food demand and address challenges in food production, including (a)biotic stresses and inadequate nutritional value. Despite reliance on conventional genetic manipulation methods, the CRISPR-Cas-mediated genome editing toolbox allows precise modification of DNA/RNA in a target organism's genome. So far, CRISPR-Cas has been widely used to enhance yield, quality, stress tolerance, and nutritional value in various food crops. However, challenges such as reagent delivery in suitable explants, precise editing with minimal off-target effect, and generating transgene-free plants persist as major bottlenecks in most plant species. Components of CRISPR-Cas construct mainly Cas, guide RNA (gRNA), and selectable marker genes are often integrated into the host genome, which raises regulatory concerns. However, adapting advanced gene-editing strategies, including high-efficiency Cas endonucleases, DNA-independent RNP delivery, morphogenetic regulators, and grafting-mediated editing, are paving the way for transgene-free crop improvement while easing biosafety regulations. Further, regulatory frameworks for genome-edited crops vary globally, with several countries accepting them and others debating their legal status. Hence, the disparity in global regulatory guidelines of genome editing curbs commercialization. The current review highlights the emerging CRISPR-mediated tools or methods and their applications in developing transgene-free designer crops to harness the benefits of advanced genome manipulation.

German chamomile (Matricaria chamomilla L.) is a traditional aromatic medicinal plant, its flower contains volatile aromatic oil (essential oil). The main sesquiterpene components of the essential oil are (E)-β-farnesene, chamazulene, and α-bisabolol, these components have significant medicinal value and are used in food, cosmetics, and pharmaceuticals. However, the German chamomile genome has not yet been cataloged in any database; consequently, research on the intricate regulatory network and interaction mechanisms among proteins in German chamomile remains limited. Furthermore, no study has thus far developed a yeast cDNA library for German chamomile. Therefore, we constructed a homogenized yeast cDNA library using different tissues of German chamomile, this yeast cDNA library had a titer of 1.444 × 10⁸ colony-forming units/mL, an average insert size of > 1,000 bp, and a positive rate of 100%. In addition, 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate synthase (HDS) that interacted with Hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate reductase (HDR) involved in the final step of the methylerythritol 4-phosphate (MEP) pathway was verified through the yeast two-hybrid (Y2H) assay and bimolecular fluorescence complementation (BiFC). At the same time, the expression pattern and function of McHDS were further analyzed. In conclusion, we successfully constructed a yeast cDNA library of German chamomile for the first time, and McHDS interacting with McHDRa/b was successfully screened, providing a reliable theoretical foundation for investigating the molecular mechanism of its coordination with McHDRa/b to regulate the biosynthesis of (E)-β-farnesene in German chamomile. Which lays the groundwork for our comprehensive understanding of the protein interaction network involved in sesquiterpene synthesis of German chamomile.

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.