Plant signaling & behavior最新文献

Aluminum stress is a critical limiting factor in crop productivity, as it rapidly inhibits root elongation, impairs water and nutrient uptake, and ultimately leads to substantial yield reductions. To address this challenge, it is essential to elucidate the mechanisms underlying plant aluminum toxicity and tolerance, thereby enhancing crop resilience to aluminum stress. In this study, we employed transcriptomic and metabolomic analyses to identify the protein TSJT1, which is induced by aluminum exposure and plays an essential role in the plant's response to aluminum. Notably, TSJT1 expression was significantly up-regulated in mpc1 mutants; furthermore, overexpression of TSJT1 markedly enhanced the plant's resistance to aluminum stress. Our integrated analysis also revealed significant differences in glutamate metabolites as well as a protein encoding glutamate synthetase during this process. Through exogenous glutamate supplementation, we demonstrated that glutamate plays a critical role in the MPC1-mediated response to aluminum stress.

Wheat is the third most widely consumed cereal in the world, after maize and rice. However, it is regularly attacked by the wheat aphid (Schizaphis graminum), causing considerable damage to wheat crops. The acetylcholinesterase enzyme, which plays a key role in the transmission of the synaptic cholinergic signal, has emerged as a promising target for the development of pest control strategies. Inhibition of this enzyme leads to the paralysis or even death of the aphid. The objective of this study is to identify the bioactive compounds in Securidaca longepedunculata (S. longepedunculata) that are capable of interacting with acetylcholinesterase from Schizaphis graminum and inhibiting its activity. Furthermore, a computer simulation of these compounds in interaction with the key protein was conducted. First, the secondary metabolites of S. longepedunculata were selected on the basis of GC-MS data available from specific reference sources. Subsequently, the compounds were subjected to virtual screening based on their docking scores in order to identify those with inhibitory properties. The compounds with the highest scores were subjected to molecular dynamics simulation over a 50 ns trajectory. Subsequently, MMGBSA free energy calculations were conducted. The results demonstrated that eight compounds exhibited inhibitory properties, four of which (echimidine, populin, salidroside, and farrerol) demonstrated superior stabilizing effects on proteins compared to the remaining compounds. In terms of free energy by MMGBSA and molecular simulation, it was observed that echimidine and populin formed robust and stable hydrogen bonds with the amino acids of the acetylcholinesterase enzyme. This study identifies and attempts to validate the potential inhibitory activities of echimidine and populin against acetylcholinesterase, with a view to developing potent insecticides and unique treatment strategies.

Drought stress inhibits the development of maize ears. Abscisic acid (ABA) is a plant hormone that can regulate the physicology metabolism under abiotic stress. In this study, maize varieties Zhengdan 958 (ZD958) and Xianyu 335 (XY335) with different filling stages were used as materials. Three treatments were set in the filling period: normal irrigation (CK), drought stress (stress); exogenous ABA + drought stress (ABA+stress). They were used to study the physiological regulation of exogenous ABA on maize ears development during drought stress. Exogenous ABA inhibited bald tip and the decline of maize plant biomass, and increased the number and weight of grains per ear at harvest under drought stress by regulating photosynthetic pigment content (Chla, Chlb, Car), gas exchange parameters (Pn, Tr, gs, Ci, Ls), Chla fluorescence parameters (Fv/Fm, ФPSII, ETR, qP, NPQ), chloroplast structure and function, photosynthetic enzyme activity, and the transcription level of genes coding SUTs (ZmSUT1, ZmSUT2, ZmSUT4, ZmSUT6). There was a significant correlation between physiological indexes of sucrose loading in maize and yield factors. This study discussed the mechanism of exogenous ABA alleviating maize ear dysplasia at grain filling stage under drought stress from the perspective of photosynthesis and sucrose transport.

Rhizosphere microorganisms play a significant role in influencing the growth and quality of tea plants (Camellia sinensis). However, the complex mechanisms underlying the interactions between rhizosphere microorganisms and tea plants require further investigation. In this study, we employed high-throughput sequencing and the isolation of functional rhizosphere microorganisms to examine variations in rhizosphere microbial diversity and functional characteristics among five distinct tea cultivars: Camellia sinensis cv. Wuniuzao, Fudingdahao, Fuyunliuhao, Jinxuan, and Fudingdabai, each recognized for its unique qualities and adaptability. Our results revealed significant differences in the community diversity of rhizosphere microorganisms among the different tea cultivars. The phylum Mucoromycota may exert a notable influence on the growth of cultivars Wuniuzao, Fudingdahao, and Fuyunliuhao through metabolic pathways such as lipid metabolism. Specifically, Serratia spp. and Enterobacter spp. which produce higher levels of IAA and were isolated from the rhizosphere soils of cultivars Wuniuzao and Fudingdahao, may play a critical role in promoting tea plant growth and development. Additionally, bacteria from the phylum Acidobacteriota may also contribute significantly to tea plant growth. These findings provide valuable insights into the roles of rhizosphere microorganisms in influencing the growth and quality of tea plants, offering a foundation for further exploration of microbial-assisted strategies to enhance tea cultivation.

Plants are continuously challenged by a myriad of pathogenic microorganisms, including bacteria, viruses, fungi and oomycetes, against which they must defend themselves. The protein Cell Division Cycle 48 (CDC48), a key player of ubiquitin-proteasome system which segregates and remodels ubiquitinated proteins for degradation, is known to be mobilized during plant immunity. Moreover, the characterization of the nuclear role of CDC48 is of interest, in particular its regulation in nuclear processes such as chromatin remodeling, DNA repair and gene expression. In this regard, its nuclear functions during plant immunity remain underexplored. This study investigates the dynamics of CDC48 during plant immune responses. The biophysical analysis using the Fluorescence Correlation Spectroscopy (FCS) on tobacco leaves stably overexpressing GFP-CDC48 revealed that the nuclear dynamics of CDC48 changed after treatment with cryptogein, an elicitor of immune responses. FCS analysis revealed an increase of the nuclear mobility of CDC48 and a faster interaction of CDC48 with a wide range of nuclear partners shortly after cryptogein treatment. Overall, our study shows a nuclear regulation of the interaction of CDC48 with its potential partners and sheds new light on potential nuclear involvements of CDC48 following the triggering of defense mechanisms.

Various metabolic and cell signaling processes impact the functions of sugarcane plant cells. MicroRNAs (miRNAs) play critical regulatory roles in enhancing yield and providing protection against various stressors. This study seeks to identify and partially characterize several novel miRNAs in sugarcane using in silico tools, while also offering a preliminary assessment of their functions. This was accomplished by predicting novel conserved miRNAs in sugarcane plants using a variety of genomics-based techniques like BLASTn, MFOLD, psRNA Target, sequence logo, Weblogo, primer-3, etc. and annotated using miRBase and NCBI. For validation, RT-PCR method was used along with agarose gel. After the preparation of fourteen randomly chosen primers, they were validated by RT-PCR. Accordingly, they contain fifty specific targeted proteins with substantial targets in the structural, transcriptional protein, etc. Furthermore, the sof-miR5025a directs the heat repeat protein while the voltage-dependent anion is governed by sof-miR8005a. Similarly, the sof-miR7768b and sof-miR6249b monitor the pathogenesis-related protein and zinc finger, C₂H₂ type protein, which assist as transcription factors. Thus, the novel sugarcane miRNAs target a wide range of important genes help regulate the environment for sugarcane to generate a higher-quality crop.

The growing human population and abiotic stresses pose significant threats to food security, with PGPR favorable as biofertilizers for plant growth and stress relief. In one study, soil samples from both cultivated and uncultivated plants in various cities were used to isolate rhizobacterial populations. Using 50 soil samples from both cultivated and uncultivated plants, isolated rhizobacterial populations were screened for various biochemical changes, PGP activities and morphological characteristics. A total of 199 rhizobacteria were isolated and screened for IAA production. The strain M28 produced maximum IAA 378.44 ± 2.5 µg ml^-1, M9 formed only 34.72 ± 0.15 µg ml^-1. About 19% of IAA producers were isolated from Multan, 18% Lahore, 15% from soils of Faisalabad and Sheikhupura, while 7% from Gujrat. The 21 isolates were drought tolerant to -0.14Mpa, 14 of those were PSB and 15 were N fixers. In PGP traits, maximum zinc solubility was expressed by M4 as 2 ± 0.5 cm of zone. The strain M22 produced amount of HCN, 40.12 ± 0.052 ppm. All isolates showed diverse behavior in biocompatibility, motility patterns and hydrophobicity. Selected drought tolerant strains were genetically identified by ribotyping. Multitrait PGPR could be effective biofertilizers rather than with single trait. The strain M28 having highest production of IAA, was gelatinase, methyl red positive and was also capable of nitrogen fixation. Moreover, it had maximum swimming (8.9 mm) and swarming (8.7 mm) activities after 24 h, indicating its best PGP traits for future use.

To determine whether photoperiod influences integrated physiological and molecular mechanisms underlying cadmium (Cd) uptake and tolerance in Sedum alfredii, plants were exposed to varying day lengths (2-24 h). Distinct photoperiod-dependent trends emerged: very short photoperiods primarily stimulated stress-related hormone signaling and early-stage flavonoid synthesis, while an intermediate photoperiod (~10 h) concurrently enhanced growth-promoting hormones, jasmonate signaling, and antioxidant defenses. This optimal photoperiod elicited a coordinated peak in phytohormonal responses, antioxidant enzyme activities, and Cd transporter gene expression. Canonical correspondence analysis identified three major co-regulatory modules integrating hormonal signaling, secondary metabolism, and heavy-metal transport. These modules included an auxin - IAA oxidase network, an ABA - phenolic metabolism axis linked to key metal transporter genes (HMA and ZIP families), and a cytokinin - flavonoid pathway associated with additional Cd transporters. The convergence of these modules underscores a systemic regulatory mechanism balancing plant growth, defense responses, and heavy-metal management. These findings provide a mechanistic understanding of how photoperiodic signals modulate endogenous hormone networks and associated molecular processes to optimize Cd accumulation and tolerance. This study thus identifies photoperiod as a pivotal environmental cue that could inform strategies to enhance S. alfredii's effectiveness in phytoremediation of Cd-contaminated soils.

Mycorrhizal fungi are known to support their host plants by facilitating nutrient acquisition and enhancing resistance to biotic and abiotic stress. However, the possibility that they also convey structural information about the soil has not yet been tested. Here, we attempted to investigate whether ectomycorrhizal hyphae could guide root growth in response to physical obstacles by using Scots pine (Pinus sylvestris) and Suillus granulatus in a microcosm experiment fitted with U-shaped silicone mazes. Despite initial success in achieving ectomycorrhizal colonisation (88% of the inoculated seedlings), the fungi failed to produce the expected hyphal networks. Extensive and unexpected root growth rendered the system unsuitable for testing our hypothesis. Furthermore, structural issues with the microcosms compromised substrate integrity, possibly inhibiting fungal development. While our results were inconclusive, this report highlights challenges associated with replicating classical ectomycorrhizal experiments, underscoring the need for methodological refinement. We provide detailed recommendations and methodological clarifications that may aid future research. Although our initial hypothesis could not be tested, we argue that traditional microcosm experiments retain potential for advancing our understanding of mycorrhizal ecology, provided they are critically revisited and technically improved. Negative results, when well contextualised, are valuable contributions toward more robust and reproducible experimental frameworks.

Gibberella stalk rot (GSR) caused by Fusarium graminearum is one of the most devastating diseases of maize, not only seriously affecting its yield and the application of mechanized harvest technology but also producing a variety of toxins, thus seriously impacting the food safety. BAK1 (Brassinosteroid-Insensitive 1-Associated Receptor Kinase 1, BAK1) is the well-studied co-receptor of PRRs (Pattern Recognition Receptors), which is involved in the regulation of growth and development regulation as well as the response to diverse biological stresses. However, little is known about the role of BAK1 in the interaction between maize and pathogens, especially in maize against GSR. In this study, we found that ZmBAK1 (Zm00001d037297) was located at the cytoplasmic membrane. Furthermore, ZmBAK1 was induced by multiple PAMPs (Pathogen-Associated Molecular Patterns), while PTI (PAMP-Triggered Immunity) response including ROS (Reactive Oxygen Species) burst and callose deposition, as well as cell death, and immune gene expression was weakened in bak1 mutant upon PAMP treatment. On the contrary, the ROS production and cell death in BAK1-OE were significantly stronger than wild type. Furthermore, bak1 mutant is more susceptible to GSR, while BAK1-OE is more resistant, compared to wild types. Taken together, our data suggested that ZmBAK1 plays a positive role in maize GSR resistance, likely via activating PTI signaling pathway.