Plant Direct最新文献

Abeliophyllum distichum (Oleaceae), endemic to the Korean Peninsula and the sole member of its genus and species, possesses high scarcity value, escalating its importance under the Nagoya Protocol. Despite its significance, their metabolites and activities of A. distichum flowers remain unexplored. This study employs an integrated metabolomic approach utilizing NMR, LC/MS, GC/MS, and FTIR techniques to comprehensively analyze the metabolite profile of A. distichum flowers. By combining these methods, we identified 35 metabolites, 43 secondary metabolites, and 108 hydrophobic primary metabolites. Notably, distinct concentration patterns of these compounds were observed across five variants, classified based on morphological characteristics. Correlation analyses of primary and secondary metabolites unveiled varietal metabolic flux, providing insights into A. distichum flower metabolism. Additionally, the reconstruction of metabolic pathways based on dissimilarities in morphological traits elucidates variant-specific metabolic signatures. These findings not only enhance our understanding of chemical differences between varieties but also underscore the importance of considering varietal differences in future research and conservation efforts.

The spatial accumulation of hordeins in the developing endosperm of barley grains was examined by immunofluorescence microscopy (immunolight microscopy [iLM]) and immunoelectron microscopy (iEM) to establish the timing and subcellular pattern of hordein synthesis and deposition. The pattern seen for hordeins was compared to other abundant grain proteins, such as serpin Z4 and lipid transfer protein 1 (LTP1). Hordein accumulates throughout grain development, from 6 to 37 days post-anthesis (DPA). In contrast, serpin Z4 was present at 6 DPA, but the greatest synthesis and accumulation occurred during the middle of seed development, from 15 to 30 DPA. LTP1 accumulated later in seed development, from 15 to 30 DPA. Hordeins accumulated within the lumen of the endoplasmic reticulum (ER), were exocytosed from the ER membrane, and accumulated in protein bodies, which then fused either with the protein storage vacuoles or with other protein bodies, which also later fused with the protein storage vacuoles. iEM showed hordein, and LTP1 appeared not to traverse the Golgi apparatus (GA). Hordein, LTP1, and serpin Z4 colocalized to the same protein bodies and were co-transported to the protein storage vacuole in the same protein bodies. It is likely that this represents a general transport mechanism common to storage proteins in developing grains.

Cytoplasmic projections (CPs) formed by the generative and sperm cells link the male gametes with the vegetative cell (VC) nucleus, which are required to build the male germ unit (MGU) assemblage in the angiosperm pollen grain. As molecular and genetic controls underlying CP development and formation of the MGU are unknown, it was hypothesized that physical association between germ cells and the VC nucleus might be lost in germ unit malformed (gum) mutants or in those which either block generative cell (GC) division or that additionally prevent gamete differentiation. In vivo, analysis of marked cellular components demonstrated a linkage of sperm cells (SCs) and the VC nucleus in gum mutant alleles despite their increased physical separation. Similarly, for several independent classes of bicellular pollen mutants, undivided GCs were associated with the VC nucleus like GCs in wild-type pollen. We conclude that the early formation of GC CPs to establish the MGU is regulated independently of DUO1-DAZ1 and DUO3 transcription factors as well as cyclin-dependent kinase function (CDKA;1). As the absence of cytoplasmic protrusion was expected in the gum mutants in Arabidopsis, early histological studies reported temporal disappearance of cytoplasmic protrusion in several organisms. Our findings demonstrated the striking importance of live imaging to verify the broad conservation of the persistent MGU contact in all the angiosperms and its important role in successful double fertilization.

In Brassicaceae self-incompatibility (SI), self-pollen rejection is initiated by the S-haplotype specific interactions between the pollen S cysteine-rich/S-locus protein 11 (SCR/SP11) ligands and the stigma S receptor kinases (SRK). In Brassica SI, a member of the Plant U-Box (PUB) E3 ubiquitin ligases, ARM-repeat containing 1 (ARC1), is then activated by SRK in this stigma and cellular events downstream of this cause SI pollen rejection by inhibiting pollen hydration and pollen tube growth. During the transition to selfing, Arabidopsis thaliana lost the SI components, SCR, SRK, and ARC1. However, this trait can be reintroduced into A. thaliana by adding back functional copies of these genes from closely related SI species. Both SCR and SRK are required for this, though the degree of SI pollen rejection varies between A. thaliana accessions, and ARC1 is not always needed to produce a strong SI response. For the A. thaliana C24 accession, only transforming with Arabidopsis lyrata SCR and SRK confers a strong SI trait (SI-C24), and so here, we investigated if ARC1-related PUBs were involved in the SI pathway in the transgenic A. thaliana SI-C24 line. Two close ARC1 homologs, PUB17 and PUB16, were selected, and (Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) technology was used to generate pub17 and pub16 mutations in the C24 accession. These mutants were then crossed into the transgenic A. thaliana SI-C24 line and their potential impact on SI pollen rejection was investigated. Overall, we did not observe any significant differences in SI responses to implicate PUB17 and PUB16 functioning in the transgenic A. thaliana SI-C24 stigma to reject SI pollen.

Soil acidity (pH <5.5) limits agricultural production due to aluminum (Al) toxicity. The primary target of Al toxicity is the plant root. However, symptoms can be observed on the shoots. This study aims to determine the potential use of chlorophyll fluorescence imaging, multispectral imaging, and 3D multispectral scanning technology to quantify the effects of Al toxicity on corn. Corn seedlings were grown for 13 days in nutrient solutions (pH 4.0) with four Al treatments: 50, 100, 200, and 400 μM and a control (0 μM AlCl₃ L^-1). During the experiment, four measurements were performed: four (MT1), six (MT2), 11 (MT3), and 13 (MT4) days after the application of Al treatments. The most sensitive traits affected by Al toxicity were the reduction of plant growth and increased reflectance in the visible wavelength (affected at MT1). The reflectance of red wavelengths increased more significantly compared to near-infrared and green wavelengths, leading to a decrease in the normalized difference vegetation index and the Green Leaf Index. The most sensitive chlorophyll fluorescence traits, effective quantum yield of PSII, and photochemical quenching coefficient were affected after prolonged Al exposure (MT3). This study demonstrates the usability of selected phenotypic traits in remote sensing studies to map Al-toxic soils and in high-throughput phenotyping studies to screen Al-tolerant genotypes.

Isoprene, a volatile hydrocarbon, is typically emitted from the leaves of many plant species. Given its well-known function in plant growth and defense aboveground, we examined its effects on root physiology. We used isoprene-emitting (IE) lines and a non-emitting (NE) line of Arabidopsis and investigated their performance by analyzing root phenotype, hormone levels, transcriptome, and metabolite profiles under both normal and salt stress conditions. We show that IE lines emitted tiny amounts of isoprene from roots and showed an increased root/shoot ratio compared with NE line. Isoprene emission exerted a noteworthy influence on hormone profiles related to plant growth and stress response, promoting root development and salt-stress resistance. Methyl erythritol 4-phosphate pathway metabolites, precursors of isoprene and hormones, were higher in the roots of IE lines than in the NE line. Transcriptome data indicated that the presence of isoprene increased the expression of key genes involved in hormone metabolism/signaling. Our findings reveal that constitutive root isoprene emission sustains root growth under saline conditions by regulating and/or priming hormone biosynthesis and signaling mechanisms and expression of key genes relevant to salt stress defense.

Tea plant (Camellia sinensis [L.]) is one of the most important crops in China, and tea branch is an important agronomic trait that determines the yield of tea plant. In previous work focused on GWAS that detecting GWAS signals related to plant architecture through whole genome re-sequencing of ancient tea plants, a gene locus TEA 029928 significantly related to plant type was found. Sequence alignment results showed that this gene belonged to the F-box family. We named it CsBRC. CsBRC-GFP fusion proteins were mainly localized in the plasma membrane. By comparing the phenotypes of CsBRC transgenic tobacco and WT tobacco, it was found that the number of branches of transgenic tobacco was significantly higher than that of wild-type tobacco. Through RNA-seq analysis, it was found that CsBRC affects the branching development of plants by regulating the expression of genes related to brassinosteroid synthesis pathway in plants. In addition, overexpression of CsBRC in rice could increase tiller number, grain length and width, and 1,000-grain weight.

Plant galls generated by insects have highly organized structures, providing nutrients and shelter to the insects living within them. Most research on the physiological and molecular mechanisms of gall development has focused on single galls. To understand the diversity of gall development, we examined five galls with different morphologies generated by distinct species of Rhopalomyia (gall midge; Diptera: Cecidomyiidae) on a single host plant of Artemisia indica var. maximowiczii (Asteraceae). Vasculature developed de novo within the galls, indicating active transport of nutrients between galls and the host plant. Each gall had a different pattern of vasculature and lignification, probably due to differences in the site of gall generation and the gall midge species. Transcriptome analysis indicated that photosynthetic and cell wall-related genes were down-regulated in leaf and stem galls, respectively, compared with control leaf and stem tissues, whereas genes involved in floral organ development were up-regulated in all types of galls, indicating that transformation from source to sink organs occurs during gall development. Our results help to understand the diversity of galls on a single herbaceous host plant.