Plant Growth Regulation最新文献

Due to their ability to act as antioxidants, many metabolites serve as plant defense chemicals. Holistic metabolomic analysis is a method to investigate UV-B radiation impacts because the metabolome directly represents the physiological state of the plant. In order to determine how the exposure to UV-B radiation affected the accumulation of primary metabolites (amino acids, organic acids), secondary metabolites (phenolic compounds, fatty acids), and their synergistic antioxidant capacity in Rhododendron chrysanthum Pall., this study used gas chromatography-time-of-flight mass spectrometry (GC-TOFMS). Metabolite analysis revealed that there were 444 metabolites in total. Most amino acids and organic acids, in particular, rose in concentration following being exposed to UV-B. Simultaneously, the levels of tricarboxylic acid cycle (TCA) intermediates and phenolic compounds grew steadily. Furthermore, after UV-B therapy, the amount of anthocyanins, which are known to be powerful antioxidants, rose. In terms of protein–protein interaction (PPI) and enzyme content, the experimental group demonstrated greater antioxidant ability. In reaction to UV-B radiation, the content of metabolites that act as antioxidants increased. This experiment proved that R. chrysanthum main and secondary metabolisms were altered by UV-B radiation. It sheds some information on the combined analysis of metabolomics and other omics in R. chrysanthum.

The heading date of rice is a crucial agronomic traits affecting regional adaptation and grain productivity. Manipulating the vegetative growth period or delaying flowering can increase the yield and quality. The RICE FLOWERING LOCUS T (RFT1) has a critical role in flowering regulation. Here, we aimed to delay flowering in rice by reducing the expression of RFT1. For this purpose, we targeted four sites within the 0.5-kb region of RFT1 promoter for gene editing. Six homozygous mutant lines were obtained (rft1 pro-1 to rft1 pro-6), which showed delayed heading dates by 1.4–9.2 days. In addition, expression levels of Hd3a and RFT1 were significantly reduced, corroborating the late flowering phenotype. Using a dual-luciferase reporter in rice protoplast, we established that the protein level of LUC driven by the edited rft1 promoter was lower than that driven by the RFT1 promoter. In conclusion, we have developed a viable strategy to delay rice flowering by editing promoter of flower-promoting gene.

Abstract

Through intricate interactions with phytohormones, sodium nitroprusside (SNP), a nitric oxide (NO) donor, has a variety of impacts on plant physiology. This comprehensive review sheds light on the significance of SNP’s in plant biology under normal and stress conditions. SNP’s history, importance in plant biology, and interactions with phytohormones must all be understood to comprehend its physiological impacts on plant growth and development. This study examines how SNP influences seed germination, root growth, flowering duration, fruit development, and resistance to biotic and abiotic challenges to improve stress tolerance and crop productivity. Based on the literature review this study explored the molecular and pharmaceutical mechanisms of SNP-phytohormone, crosstalk affects, important signaling pathways, including calcium-dependent signaling and MAPK cascades. The requirement for tailored application strategies is highlighted by the fact that different plant species and genotypes react to SNP treatment differently depending on the context. This study also discussed the consequences of environmental and agricultural sustainability, emphasizing SNP’s potential to improve stress tolerance, pest control, and crop output. For sustainable, practical applications, it also underlines the necessity to handle obstacles and constraints such as concentration-dependent effects and potential environmental repercussions. Understanding the complex interactions between SNP and phytohormones provides doors for sustainable agriculture and biotechnology advancements. This comprehensive study offers encouraging possibilities for solving major issues in agriculture and environmental resilience by illuminating the molecular and physiological mechanisms.

Salt stress is a major cause of crop failure worldwide. In this study, a plant growth-promoting rhizobacteria (PGPR) strain Bacillus cereus BC56 was isolated from the rhizosphere soil of cucumber. BC56 has the ability to produce NH₃ and siderophore, and to solubilize phosphorus to promote cucumber growth. Under 100 mM NaCl treatment, BC56 significantly increased shoot length (1.28-fold), root length (1.16-fold), shoot fresh weight (1.19-fold), root fresh weight (1.54-fold), and chlorophyll fluorescence parameter of ABS/CS_m (1.19-fold), TR₀/CS_m (1.22-fold), ET₀/CS_m (1.52-fold), SPAD (1.12-fold) of cucumber seedlings compared to the cucumber without BC56 inoculation. Physiological and biochemical analysis showed that BC56 could increase the content of total soluble sugars (TSS, 1.36-fold) in cucumber seedlings. BC56 also increased peroxidase (POD, 1.17-fold) and glutathione reductase (GR, 2.59-fold) activity of cucumber seedlings, which can scavenge reactive oxygen species (ROS) to reduce salt toxicity. However, cucumber seedlings inoculated with BC56 showed a 0.59-fold decrease in abscisic acid (ABA) compared to those uninoculated with BC56. RNA-seq results showed that BC56 induced changes in the expression of a significant number of genes related to photosynthesis, phytohormones, transcriptional regulation, metabolite synthesis and metabolism, and cellular components in cucumber under salt stress, suggesting its role in reducing the deleterious effects of salinity. We concluded that BC56 can alleviate salt stress in cucumber seedlings by affecting photosynthesis, phytohormone levels, osmotic and antioxidant regulation.

Abstract

The date palm (Phoenix dactylifera) is an important cultivated crop in arid areas. Here, we studied the effect of plant genotype and type of fertilizers on the eukaryotic community structures of the date palm rhizosphere. Samples were collected from one wild population, five cultivars from two farms, and a factorial fertilizer experiment (organic, chemical, and biofertilizer) in Qatar. The eukaryotic communities were sequenced using a next-generation sequencing method. A total of 2422 Operational Taxonomic Units (OTUs) were identified as belonging to 15 phyla, Chlorophyta, Streptophyta, Imbricatea, Chytridiomycota, Ascomycota, Olpidiomycota, being dominant. The wild-type date palms showed a low number of OTUs compared to cultivated date palms, potentially due to the strong influence of soil salinity and low moisture level. However, the wild-type date palm hosted the highest number of unique OTUs. PCA revealed that the eukaryotic microbiome of the wild date palms was separated from the cultivated date palms and that the eukaryotic microbial diversity varied between date palm cultivars in similar environments. Using the highest amounts of biofertilizer and chemical fertilizer decreased the species diversity within the samples. However, a high concentration of biofertilizer combined with a low concentration of chemical fertilizers enhanced the eukaryotic diversity within the samples. We conclude that cultivar type (biotic factor), type of fertilizer, and dosage (abiotic factor) play significant roles in determining the microbiome diversity of the rhizosphere. The wild date palm population could potentially host salt and drought-tolerating eukaryotes that should be further investigated for future development of biofertilizers suitable for drylands.

Abstract

The regulatory nucleotide, guanosine 3′,5′-bis(pyrophosphate) (ppGpp), originally identified in Escherichia coli, controls transcription, translation and enzyme activities in bacteria and plastids of plant cells. We recently reported that seedlings of the ppGpp over-producing mutant of Arabidopsis thaliana grown on agar-solidified medium showed larger biomass than those of wild type (WT), especially under nutrient-limiting conditions. However, the reproducibility of the phenotype on the soil is unknown. To better understand the impact of the ppGpp accumulation on plant growth on the soil, phenotypes of the Arabidopsis ppGpp-less and ppGpp-accumulating mutants were characterized on nitrogen-rich and nitrogen-limiting soil. We found that although fresh weight of the ppGpp-accumulating mutant was significantly larger than that of WT under nitrogen-limiting conditions, dry weights of the mutants were the same as that of WT, indicating that impact of the ppGpp accumulation on plant biomass relies on growth conditions. These results confirmed that artificial modulation of ppGpp-dependent plastidial stringent response could contribute to plant growth on soil in response to nitrogen availability.

In plants, the basic leucine zipper (bZIP) family of transcription factors is known for its large size and diversity. Many studies have shown that bZIP transcription factors play an indispensable role in the growth and development of plants; however, there are few reports about the regulation of starch content in grain. To understand the genetic members of the bZIP family, using newly available wheat genome data, we compared our identification of 181 Triticum aestivum bZIP (TabZIP) genes to those reported in earlier studies. Some duplicate genes and incorrect annotations in previous studies were supplemented and corrected. Through phylogenetic analysis, transcriptome data, quantitative reverse transcription PCR (qRT-PCR), a dual-luciferase reporter (DLR), and subcellular localization analysis were used to identify transcription factors that may be involved in grain starch synthesis. We divided genes into 13 known groups and five unknown groups by phylogenetic analysis. All of the bZIP genes exhibited a minimum of one bZIP motif in their motif distribution and gene structure. Spatial and temporal expression patterns of bZIP family members during various stages of plant growth vary, as suggested by transcriptome data, and several genes were specifically expressed during grain development. As per the expression data obtained via qRT-PCR, over 10 TabZIP genes showed similarity with starch synthesis in wheat. The in-vitro binding activity of TabZIP68 to the promoter of TaWaxy was demonstrated by a DLR assay. Expression level of TabZIP68 was affected by different plant hormones treated with developing grains. Given its potential involvement in starch synthesis, the TabZIP68 gene presents itself as a strong candidate for further investigation.

Leaf color is a highly important agronomic trait, and mutants with altered leaf coloration can serve as excellent models for studies on chloroplast development and chlorophyll biosynthesis, enabling the cloning of genes involved in these processes in rice (Oryza sativa L.). In this study, we isolated a stable genetic rice mutant, oryza sativa albino leaf 50 (osal50), from a breeding population of the japonica cultivar GP50. This mutant exhibited a distinctive albino phenotype, with white-striped leaves in seedlings and white panicles at the heading stage. Compared with wild-type GP50, the osal50 mutant showed lower chlorophyll and carotenoid accumulation, together with abnormal chloroplast ultrastructure. Genetic analysis demonstrated that a recessive nuclear gene was responsible for the albino phenotype of osal50, and a map-based cloning strategy delimited OsAL50 to a 160-kb physical interval on chromosome 1, flanked by two single nucleotide polymorphism (SNP) markers, CAPS-08 and CAPS-37, that included 26 putative open reading frames. Sequence and expression analyses revealed LOC_Os01g20110 as the candidate OsAL50 gene, which was confirmed by knockout using CRISPR/Cas9. Subcellular localization and protein sequence analyses suggested that OsAL50 likely encodes an endoribonuclease E-like protein localized to the chloroplasts. Further investigation indicated that OsAL50 plays a vital role in the regulation of photosynthetic pigment metabolism, photosynthesis, and chloroplast biogenesis. In summary, we identified a novel albino mutant that will serve as useful genetic material for studies of chlorophyll biosynthesis and chloroplast development in rice.

Soil salinity seriously restricts agricultural production. Halophytes adapt to saline environments through several strategies, including leaf or stem succulence. Succulence is associated with the increase in cell size or leaf thickness and high water content per unit of surface area, allowing salts to be diluted within the succulent leaves or stems. The proposed mechanisms of NaCl-induced plant tissue succulence include acidification and subsequent induction of cell wall elasticity, increased water uptake, cell turgor pressure, Na⁺ partitioning in vacuoles, abundance of plasma membrane aquaporins, cell wall formation and extensibility, as well as up-regulation of certain genes (e.g., XTH and CEB1) that control cell expansion and cell wall modification. However, the information on the mechanism of succulence activated by salinity is limited. In this paper, the possible mechanism of salinity-induced succulence, and the role of succulence in plant salt tolerance, are discussed. Understanding the mechanisms that activate succulence in halophytes opens up new opportunities for plant breeding to increase salt tolerance and improve crop productivity in saline soils.

Plant organ abscission is a fundamental biological process. and is a stress and evolutionary mechanism formed to adapt to environmental changes due to external signal stimulation or age development. Flower, leaf and fruit abscission are common in production, not only in vivo plants but also in in vitro culture. Breakthroughs have been made in organ abscission studies for model plants and crops in vivo plants, but little is known about organ abscission in in vitro culture, which is a complex biological process. This paper reviews the organ abscission mechanism from the perspectives of cell histology, physiological biochemistry and molecular biology and looks forward to organ abscission research, which aims to fully clarify the plant organ abscission mechanism and provide theoretical and technical guidance for the normal/abnormal abscission of plant organs in actual production.