Plant Molecular Biology最新文献

BoORP3a, an oxysterol-binding protein, located in the endoplasmic reticulum (ER), may function in cuticular wax deposition in ornamental kale. In this study, we investigated its regulation of the key components of cuticular wax and lipids, metabolic pathways, and potential target genes. HS-SPME/GC-MS identified 34 and 31 volatile organic compounds in wild-type and the BoORP3a-overexpressing plant OE-ORP3a-7, respectively, primarily including alkane, ketone, ester, and alcohol. Hentriacontane, 15-nonacosanone, and > C₂₀ alkanes were more abundant in OE-ORP3a-7, which may result in more cuticular wax in this plant. RNA sequencing identified 223 differentially expressed genes (DEGs) between wild-type and OE-ORP3a-7, comprising 119 upregulated and 104 downregulated DEGs. The KEGG enrichment analysis revealed that the downregulated DEGs in OE-ORP3a-7 were involved in glyoxylate and dicarboxylate metabolism, SNARE (Soluble N-ethylmaleimide-sensitive factor attachment protein receptor) interactions in vesicular transport, fatty acid biosynthesis, and glycerolipid metabolism; the upregulated DEGs were involved in steroid biosynthesis, fatty acid degradation, alpha-linolenic acid metabolism, and sphingolipid metabolism. Bo1g106990, Bo1g123670, and Bo9g166090 were identified as key DEGs in lipid-related pathways. We speculate that BoORP3a regulates several lipid metabolisms and may coordinate lipid turnover and remodeling. The results of this study will enrich the functionality of the ORPs family, provide new insights into plant wax research, and have significant implications for ornamental kale breeding.

Essential plant nutrients encapsulated or combined with nano-dimensional adsorbents define nano fertilizers (NFs). Nanoformulation of non-essential elements enhancing plant growth and stress tolerance also comes under the umbrella of NFs. NFs have an edge over conventional chemical fertilizers, viz., higher plant biomass and yield using much lesser fertilization, thereby reducing environmental pollution. Foliar and root applications of NFs lead to their successful uptake by the plant, depending on the size, surface charge, and other physicochemical properties of NFs. Smaller NFs can pass through channels on the waxy cuticle depending on the hydrophobicity, while larger NFs pass through the stomatal conduits of leaves. Charge-based adsorption, followed by apoplastic movement and endocytosis, translocates NFs through the root, while the size of NFs influences passage into vascular tissues. Recent transcriptomic, proteomic, and metabolomic studies throw light on the molecular mechanisms of growth promotion by NFs. The expression levels of nutrient transporter genes are regulated by NFs, controlling uptake and minimizing excess nutrient toxicity. Accelerated growth by NFs is brought about by their extensive regulation of cell division, photosynthesis, carbohydrate, and nitrogen metabolism, as well as the phytohormone-dependent signaling pathways related to development, stress response, and plant defense. NFs mimic Ca,²⁺ eliciting second messengers and associated proteins in signaling cascades, reaching transcription factors and finally orchestrating gene expression to enhance growth and stress tolerance. Developing advanced nano fertilizers of the future must involve exploring molecular interactions with plants to reduce toxicity and improve effectiveness.

Barley (Hordeum vulgare L.) is the fourth largest cereal crop in the world after rice, wheat and maize. Barley yellow mosaic disease (BYMD) is a serious threat to winter barley production. The evolution and mutation of virus strains lead to the breakdown of the resistance of the originally resistant varieties. It is therefore vital to explore new BYMD resistance genes. In this study, a natural population (334 barley varieties or lines) and a double haploid population derived from the cross between Tam407227 and Franklin were used to search for new quantitative trait loci (QTL) for BYMD resistance. Two major QTL on chromosomes 3H and 7H, respectively, were detected from the genome wide association study and validated in the DH population. Among them, The QTL on 3H (qRYM-3H/qTFRYM-3H) was confirmed to be the reported BYMD resistance gene eIF4E by haplotype analysis. And the QTL on 7H (qRYM-7H/qTFRYM-7H) is a novel QTL that has not been reported before. Another QTL on 2H was identified from the DH population. This QTL is more likely the Rmy16^Hb reported previously. These three QTL showed an additive effect on improving BYMD resistance with the average disease scores from 2.45 (all sensitive alleles for these three QTL) to 0.62 (all tolerant alleles for these three QTL). The candidate genes for the novel QTL qRYM-7H/qTFRYM-7H were predicted based on transcriptome sequencing and qPCR analysis.

Industrial hemp (Cannabis sativa L.) is a multifaced crop that has the potential to be exploited for many industrial applications, and making use of salt lands is considered to be a sustainable development strategy for the hemp industry. However, no elite salt-tolerant hemp varieties have been developed, and therefore supplementing appropriate exogenous substances to saline soil is one possible solution. Calcium-containing compounds are well-known for their salt tolerance enhancing effects, but the underlying molecular mechanisms remain largely unclear. Here, we first assessed the ameliorative effects of calcium amendments on salt-stressed hemp plants and then investigated these mechanisms on hemp using integrative analysis of proteomics and metabolomics. The stress phenotypes could be lessened by Ca²⁺ treatment. Certain concentrations of Ca²⁺ maintained relative electrical conductivity and the contents of malondialdehyde and chlorophyll. Ca²⁺ treatment also generally led to greater accumulations of soluble proteins, soluble carbohydrates and proline, and enhanced the activities of superoxide dismutase and peroxidase. Through functional classification, pathway enrichment, and network analysis, our data reveal that accumulation of dipeptides is a prominent metabolic signature upon exogenous Ca²⁺ treatment, and that changes in mitochondrial properties may play an important role in enhancing the salt tolerance. Our results outline the complex metabolic alternations involved in calcium-mediated salt stress resistance, and these data and analyses would be useful for future functional studies.

Existence of potent in vitro regeneration system is a prerequisite for efficient genetic transformation and functional genomics of crop plants. In this study, two contrasting cultivars differencing in their in vitro regeneration efficiency were identified. Tissue culture friendly cultivar Golden Promise (GP) and tissue culture resistant DWRB91(D91) were selected as contrasting cultivars to investigate the molecular basis of regeneration efficiency through multiomics analysis. Transcriptomics analysis revealed 1487 differentially expressed genes (DEGs), in which 795 DEGs were upregulated and 692 DEGs were downregulated in the GP-D91 transcriptome. Genes encoding proteins localized in chloroplast and involved in ROS generation were upregulated in the embryogenic calli of GP. Moreover, proteome analysis by LC-MS/MS revealed 3062 protein groups and 16,989 peptide groups, out of these 1586 protein groups were differentially expressed proteins (DEPs). Eventually, GC-MS based metabolomics analysis revealed the higher activity of plastids and alterations in key metabolic processes such as sugar metabolism, fatty acid biosynthesis, and secondary metabolism. TEM analysis also revealed differential plastid development. Higher accumulation of sugars, amino acids and metabolites corresponding to lignin biosynthesis were observed in GP as compared to D91. A comprehensive examination of gene expression, protein profiling and metabolite patterns unveiled a significant increase in the genes encompassing various functions, such as ion homeostasis, chlorophyll metabolic process, ROS regulation, and the secondary metabolic pathway.

Arbuscular mycorrhizal fungi (AMF) serve as both plant symbionts and allies in resisting pathogens and environmental stresses. Mycorrhizal colonization of plant roots can influence the outcomes of plant-pathogen interactions by enhancing specific host defense mechanisms. The transcriptional responses induced by AMF in virus-infected plants remain largely unexplored. In the presented study, we employed a comprehensive transcriptomic approach and qPCR to investigate the molecular determinants underlying the interaction between AMF and potato virus Y (PVY) in Solanum tuberosum L. Our primary goal was to identify the symbiosis- and defense-related determinants activated in mycorrhizal potatoes facing PVY. Through a comparative analysis of mRNA transcriptomes in experimental treatments comprising healthy and PVY-infected potatoes colonized by two AMF species, Rhizophagus regularis or Funneliformis mosseae, we unveiled the overexpression of genes associated with mycorrhiza, including nutrient exchange, lipid transfer, and cell wall remodeling. Furthermore, we identified several differentially expressed genes upregulated in all mycorrhizal treatments that encoded pathogenesis-related proteins involved in plant immune responses, thus verifying the bioprotective role of AMF. We investigated the relationship between mycorrhiza levels and PVY levels in potato leaves and roots. We found accumulation of the virus in the leaves of mycorrhizal plants, but our studies additionally showed a reduced PVY content in potato roots colonized by AMF, which has not been previously demonstrated. Furthermore, we observed that a virus-dependent reduction in nutrient exchange could occur in mycorrhizal roots in the presence of PVY. These findings provide an insights into the interplay between virus and AMF.

Wild wheat relative Aegilops biuncialis offers valuable traits for crop improvement through interspecific hybridization. However, gene transfer from Aegilops has been hampered by difficulties in detecting introgressed U^b- and M^b-genome chromatin in the wheat background at high resolution. The present study applied DArTseq technology to genotype two backcrossed populations (BC382, BC642) derived from crosses of wheat line Mv9kr1 with Ae. biuncialis accession, MvGB382 (early flowering and drought-tolerant) and MvGB642 (leaf rust-resistant). A total of 11,952 Aegilops-specific Silico-DArT markers and 8,998 wheat-specific markers were identified. Of these, 7,686 markers were assigned to U^b-genome chromosomes and 4,266 to M^b-genome chromosomes and were ordered using chromosome scale reference assemblies of hexaploid wheat and Ae. umbellulata. U^b-genome chromatin was detected in 5.7% of BC382 and 22.7% of BC642 lines, while 88.5% of BC382 and 84% of BC642 lines contained M^b-genome chromatin, predominantly the chromosomes 4M^b and 5M^b. The presence of alien chromatin was confirmed by microscopic analysis of mitotic metaphase cells using GISH and FISH, which allowed precise determination of the size and position of the introgression events. New Mv9kr1-Ae. biuncialis MvGB382 4M^b and 5M^b disomic addition lines together with a 5DS.5DL-5M^bL recombination were identified. A possible effect of the 5M^bL distal region on seed length has also been observed. Moreover, previously developed Mv9kr1-MvGB642 introgression lines were more precisely characterized. The newly developed cytogenetic stocks represent valuable genetic resources for wheat improvement, highlighting the importance of utilizing diverse genetic materials to enhance wheat breeding strategies.

The genome sizes of angiosperms decreased significantly more than the genome sizes of their ancestors (pteridophytes and gymnosperms). Decreases in genome size involve a highly complex process, with remnants of the genome size reduction scattered across the genome and not directly linked to specific genomic structures. This is because the associated mechanisms operate on a much smaller scale than the mechanisms mediating increases in genome size. This review thoroughly summarizes the available literature regarding the molecular mechanisms underlying genome size reductions and introduces Utricularia gibba and Arabidopsis thaliana as model species for the examination of the effects of these molecular mechanisms. Additionally, we propose that phosphorus deficiency and drought stress are the major external factors contributing to decreases in genome size. Considering these factors affect almost all land plants, angiosperms likely gained the mechanisms for genome size reductions. These environmental factors may affect the retention rates of deletions, while also influencing the mutation rates of deletions via the functional diversification of the proteins facilitating double-strand break repair. The biased retention and mutation rates of deletions may have synergistic effects that enhance deletions in intergenic regions, introns, transposable elements, duplicates, and repeats, leading to a rapid decrease in genome size. We suggest that these selection pressures and associated molecular mechanisms may drive key changes in angiosperms during recurrent cycles of genome size decreases and increases.

Amaryllidaceae alkaloids (AAs), such as galanthamine and lycorine, are natural products of Lycoris radiata possessing various pharmacological activities including anti-acetylcholinesterase, anti-inflammatory, and antitumour activities. Elucidating the biosynthesis of these special AAs is crucial for understanding their production and potential modification for improved clinical application, of which cytochrome P450 enzymes catalyse the formation of key alkaloid skeletons and subsequent modification processes, with the NAPDH cytochrome P450 reductases (CPRs) serving as essential redox partners. This study identified three CPRs, LrCPR1, LrCPR2, and LrCPR3, encoding 700, 697 and 695 amino acids, respectively, which belong to Class II CPRs. The LrCPRs reduced cytochrome c and ferricyanide in an NADPH-dependent manner, and their activities all followed the typical Michaelis-Menten curve. In yeast, the co-expression of LrCPRs and CYP96T6 produced the galantamine-like alkaloid namely N-demethylnarwedine, suggesting that they support the catalytic activity of CYP96T6. Quantitative analysis of the transcriptional expression profiles showed that LrCPRs were expressed in all the examined tissues of L. radiata, and their gene expression patterns are consistent with other genes that may be involved in the biosynthetic pathway of AAs, including cinnamate 4-hydroxylase and phenylalanine ammonia-lyase. Our study firstly provides the functional characterization of LrCPRs in L. radiata, which will contribute to the discovery of biosynthetic pathways and heterologous production of AAs.