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BMC Plant Biology May 2024Potato serves as a major non-cereal food crop and income source for small-scale growers in Punjab, Pakistan. Unfortunately, improper fertilization practices have led to...
BACKGROUND
Potato serves as a major non-cereal food crop and income source for small-scale growers in Punjab, Pakistan. Unfortunately, improper fertilization practices have led to low crop yields, worsened by challenging environmental conditions and poor groundwater quality in the Cholistan region. To address this, we conducted an experiment to assess the impact of two fertilizer application approaches on potato cv. Barna using plant growth-promoting bacteria (PGPB) coated biofertilizers. The first approach, termed conventional fertilizer application (CFA), involved four split applications of PGPB-coated fertilizers at a rate of 100:75 kg acre (N and P). The second, modified fertilizer application (MFA), employed nine split applications at a rate of 80:40 kg acre.
RESULTS
The MFA approach significantly improved various plant attributes compared to the CFA. This included increased plant height (28%), stem number (45%), leaf count (46%), leaf area index (36%), leaf thickness (three-folds), chlorophyll content (53%), quantum yield of photosystem II (45%), photosynthetically active radiations (56%), electrochromic shift (5.6%), proton flux (24.6%), proton conductivity (71%), linear electron flow (72%), photosynthetic rate (35%), water use efficiency (76%), and substomatal CO (two-folds), and lowered non-photochemical quenching (56%), non-regulatory energy dissipation (33%), transpiration rate (59%), and stomatal conductance (70%). Additionally, the MFA approach resulted in higher tuber production per plant (21%), average tuber weight (21.9%), tuber diameter (24.5%), total tuber yield (29.1%), marketable yield (22.7%), seed-grade yield (9%), specific gravity (9.6%), and soluble solids (7.1%). It also reduced undesirable factors like goli and downgrade yields by 57.6% and 98.8%, respectively. Furthermore, plants under the MFA approach exhibited enhanced nitrogen (27.8%) and phosphorus uptake (40.6%), with improved N (26.1%) and P uptake efficiency (43.7%) compared to the CFA approach.
CONCLUSION
The use of PGPB-coated N and P fertilizers with a higher number of splits at a lower rate significantly boosts potato production in the alkaline sandy soils of Cholistan.
Topics: Fertilizers; Phosphorus; Solanum tuberosum; Nitrogen; Pakistan; Soil; Bacteria
PubMed: 38724922
DOI: 10.1186/s12870-024-05056-x -
Frontiers in Chemistry 2024Since the dawn of photochemistry 150 years ago, photoreactions have been conducted under polychromatic light. However, despite the pivotal role that photokinetics should...
Since the dawn of photochemistry 150 years ago, photoreactions have been conducted under polychromatic light. However, despite the pivotal role that photokinetics should naturally play for such reactive photosystems, the literature lacks a comprehensive description of that area. Indeed, one fails to identify explicit model integrated rate laws for these reactions, a characteristic type for their kinetic behavior, or their kinetic order. In addition, there is no consensus in the community on standardized investigative tools to evaluate the reactivity of these photosystems, nor are there venues for the discussion of such photokinetic issues. The present work is a contribution addressing some of these knowledge gaps. It proposes an unprecedented general formula capable of mapping out the kinetic traces of photoreactions under polychromatic light irradiation. This article quantitatively discusses several reaction situations, including the effects of initial reactant concentration and the presence of spectator molecules. It also develops a methodology for standardizing actinometers and defines and describes both the spectral range of highest reactivity and the photonic yield. The validity of the model equation has been proven by comparing its results to both theoretical counterparts and those generated by fourth-order Runge-Kutta numerical calculations. For the first time, a confirmation of the -order character of the kinetics under polychromatic light was established.
PubMed: 38711947
DOI: 10.3389/fchem.2024.1367276 -
Accounts of Chemical Research May 2024ConspectusNature has established a sustainable way to maintain aerobic life on earth by inventing one of the most sophisticated biological processes, namely, natural...
ConspectusNature has established a sustainable way to maintain aerobic life on earth by inventing one of the most sophisticated biological processes, namely, natural photosynthesis, which delivers us with organic matter and molecular oxygen derived from the two abundant resources sunlight and water. The thermodynamically demanding photosynthetic water splitting is catalyzed by the oxygen-evolving complex in photosystem II (OEC-PSII), which comprises a distorted tetramanganese-calcium cluster (CaMnO) as catalytic core. As an ubiquitous concept for fine-tuning and regulating the reactivity of the active site of metalloenzymes, the surrounding protein domain creates a sophisticated environment that promotes substrate preorganization through secondary, noncovalent interactions such as hydrogen bonding or electrostatic interactions. Based on the high-resolution X-ray structure of PSII, several water channels were identified near the active site, which are filled with extensive hydrogen-bonding networks of preorganized water molecules, connecting the OEC with the protein surface. As an integral part of the outer coordination sphere of natural metalloenzymes, these channels control the substrate and product delivery, carefully regulate the proton flow by promoting pivotal proton-coupled electron transfer processes, and simultaneously stabilize short-lived oxidized intermediates, thus highlighting the importance of an ordered water network for the remarkable efficiency of the natural OEC.Transferring this concept from nature to the engineering of artificial metal catalysts for fuel production has fostered the fascinating field of metallosupramolecular chemistry by generating defined cavities that conceptually mimic enzymatic pockets. However, the application of supramolecular approaches to generate artificial water oxidation catalysts remained scarce prior to our initial reports, since such molecular design strategies for efficient activation of substrate water molecules in confined nanoenvironments were lacking. In this Account, we describe our research efforts on combining the state-of-the art Ru(bda) catalytic framework with structurally programmed ditopic ligands to guide the water oxidation process in defined metallosupramolecular assemblies in spatial proximity. We will elucidate the governing factors that control the quality of hydrogen-bonding water networks in multinuclear cavities of varying sizes and geometries to obtain high-performance, state-of-the-art water oxidation catalysts. Pushing the boundaries of artificial catalyst design, embedding a single catalytic Ru center into a well-defined molecular pocket enabled sophisticated water preorganization in front of the active site through an encoded basic recognition site, resulting in high catalytic rates comparable to those of the natural counterpart OEC-PSII.To fully explore their potential for solar fuel devices, the suitability of our metallosupramolecular assemblies was demonstrated under (electro)chemical and photocatalytic water oxidation conditions. In addition, testing the limits of structural diversity allowed the fabrication of self-assembled linear coordination oligomers as novel photocatalytic materials and long-range ordered covalent organic framework (COF) materials as recyclable and long-term stable solid-state materials for future applications.
PubMed: 38710509
DOI: 10.1021/acs.accounts.4c00148 -
BMC Plant Biology May 2024Cadmium (Cd) pollution has declined crop yields and quality. Selenium (Se) is a beneficial mineral element that protects plants from oxidative damage, thereby improving...
BACKGROUND
Cadmium (Cd) pollution has declined crop yields and quality. Selenium (Se) is a beneficial mineral element that protects plants from oxidative damage, thereby improving crop tolerance to heavy metals. The molecular mechanism of Se-induced Cd tolerance in rice (Oryza sativa) is not yet understood. This study aimed to elucidate the beneficial mechanism of Se (1 mg/kg) in alleviating Cd toxicity in rice seedlings.
RESULTS
Exogenous selenium addition significantly improved the toxic effect of cadmium stress on rice seedlings, increasing plant height and fresh weight by 20.53% and 34.48%, respectively, and increasing chlorophyll and carotenoid content by 16.68% and 15.26%, respectively. Moreover, the MDA, ·OH, and protein carbonyl levels induced by cadmium stress were reduced by 47.65%, 67.57%, and 56.43%, respectively. Cell wall metabolism, energy cycling, and enzymatic and non-enzymatic antioxidant systems in rice seedlings were significantly enhanced. Transcriptome analysis showed that the expressions of key functional genes psbQ, psbO, psaG, psaD, atpG, and PetH were significantly up-regulated under low-concentration Se treatment, which enhanced the energy metabolism process of photosystem I and photosystem II in rice seedlings. At the same time, the up-regulation of LHCA, LHCB family, and C4H1, PRX, and atp6 functional genes improved the ability of photon capture and heavy metal ion binding in plants. Combined with proteome analysis, the expression of functional proteins OsGSTF1, OsGSTU11, OsG6PDH4, OsDHAB1, CP29, and CabE was significantly up-regulated under Se, which enhanced photosynthesis and anti-oxidative stress mechanism in rice seedlings. At the same time, it regulates the plant hormone signal transduction pathway. It up-regulates the expression response process of IAA, ABA, and JAZ to activate the synergistic effect between each cell rapidly and jointly maintain the homeostasis balance.
CONCLUSION
Our results revealed the regulation process of Se-mediated critical metabolic pathways, functional genes, and proteins in rice under cadmium stress. They provided insights into the expression rules and dynamic response process of the Se-mediated plant resistance mechanism. This study provided the theoretical basis and technical support for crop safety in cropland ecosystems and cadmium-contaminated areas.
Topics: Oryza; Selenium; Cadmium; Seedlings; Plant Proteins; Proteomics; Gene Expression Regulation, Plant; Stress, Physiological; Gene Expression Profiling; Transcriptome; Genes, Plant
PubMed: 38698342
DOI: 10.1186/s12870-024-05076-7 -
Frontiers in Plant Science 2024Low temperature (LT) and weak light (WL) seriously affects the yield and quality of snapdragon in winter greenhouse. Arbuscular mycorrhizal fungi (AMF) exert positive...
INTRODUCTION
Low temperature (LT) and weak light (WL) seriously affects the yield and quality of snapdragon in winter greenhouse. Arbuscular mycorrhizal fungi (AMF) exert positive role in regulating growth and enhancing abiotic stress tolerance in plants. Nevertheless, the molecular mechanisms by AMF improve the LT combined with WL (LTWL) tolerance in snapdragon remain mostly unknown.
METHODS
We compared the differences in root configuration, osmoregulatory substances, enzymatic and non-enzymatic antioxidant enzyme defense systems and transcriptome between AMF-inoculated and control groups under LT, WL, low light, and LTWL conditions.
RESULTS
Our analysis showed that inoculation with AMF effectively alleviated the inhibition caused by LTWL stress on snapdragon root development, and significantly enhanced the contents of soluble sugars, soluble proteins, proline, thereby maintaining the osmotic adjustment of snapdragon. In addition, AMF alleviated reactive oxygen species damage by elevating the contents of AsA, and GSH, and the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR), and glutathione reductase (GR). RNA-seq analysis revealed that AMF regulated the expression of genes related to photosynthesis (photosystem I related proteins, photosystem II related proteins, chlorophyll a/b binding protein), active oxygen metabolism (POD, Fe-SOD, and iron/ascorbate family oxidoreductase), plant hormone synthesis ( and ) and stress-related transcription factors gene (, and ) under LTWL stress.
DISCUSSION
We concluded that mycorrhizal snapdragon promotes root development and LTWL tolerance by accumulation of osmoregulatory substances, activation of enzymatic and non-enzymatic antioxidant defense systems, and induction expression of transcription factor genes and auxin synthesis related genes. This study provides a theoretical basis for AMF in promoting the production of greenhouse plants in winter.
PubMed: 38681217
DOI: 10.3389/fpls.2024.1330032 -
Molecular Phylogenetics and Evolution Jul 2024Dinoflagellates are diverse and ecologically important protists characterized by many morphological and molecular traits that set them apart from other eukaryotes. These...
Dinoflagellates are diverse and ecologically important protists characterized by many morphological and molecular traits that set them apart from other eukaryotes. These features include, but are not limited to, massive genomes organized using bacterially-derived histone-like proteins (HLPs) and dinoflagellate viral nucleoproteins (DVNP) rather than histones, and a complex history of photobiology with many independent losses of photosynthesis, numerous cases of serial secondary and tertiary plastid gains, and the presence of horizontally acquired bacterial rhodopsins and type II RuBisCo. Elucidating how this all evolved depends on knowing the phylogenetic relationships between dinoflagellate lineages. Half of these species are heterotrophic, but existing molecular data is strongly biased toward the photosynthetic dinoflagellates due to their amenability to cultivation and prevalence in culture collections. These biases make it impossible to interpret the evolution of photosynthesis, but may also affect phylogenetic inferences that impact our understanding of character evolution. Here, we address this problem by isolating individual cells from the Salish Sea and using single cell, culture-free transcriptomics to expand molecular data for dinoflagellates to include 27 more heterotrophic taxa, resulting in a roughly balanced representation. Using these data, we performed a comprehensive search for proteins involved in chromatin packaging, plastid function, and photoactivity across all dinoflagellates. These searches reveal that 1) photosynthesis was lost at least 21 times, 2) two known types of HLP were horizontally acquired around the same time rather than sequentially as previously thought; 3) multiple rhodopsins are present across the dinoflagellates, acquired multiple times from different donors; 4) kleptoplastic species have nucleus-encoded genes for proteins targeted to their temporary plastids and they are derived from multiple lineages, and 5) warnowiids are the only heterotrophs that retain a whole photosystem, although some photosynthesis-related electron transport genes are widely retained in heterotrophs, likely as part of the iron-sulfur cluster pathway that persists in non-photosynthetic plastids.
Topics: Dinoflagellida; Phylogeny; Photosynthesis; Heterotrophic Processes; Biological Evolution; Evolution, Molecular; Plastids
PubMed: 38677354
DOI: 10.1016/j.ympev.2024.108086 -
International Journal of Molecular... Apr 2024Cold stress adversely impacts grape growth, development, and yield. Therefore, improving the cold tolerance of grape is an urgent task of grape breeding. The Jasmonic...
Cold stress adversely impacts grape growth, development, and yield. Therefore, improving the cold tolerance of grape is an urgent task of grape breeding. The Jasmonic acid (JA) pathway responsive gene plays a key role in plant response to cold stress. However, the role of in response to low temperatures in grape is unclear. In this study, was cloned from the 'Pinot Noir' ( cv. 'Pinot Noir') grape, and the potential interacting protein of VvJAZ13 was screened by yeast two-hybrid (Y2H). The function of under low temperature stress was verified by genetic transformation. Subcellular localization showed that the gene was mainly expressed in cytoplasm and the nucleus. Y2H indicated that VvF-box, VvTIFY5A, VvTIFY9, Vvbch1, and VvAGD13 may be potential interacting proteins of VvJAZ13. The results of transient transformation of grape leaves showed that improved photosynthetic capacity and reduced cell damage by increasing maximum photosynthetic efficiency of photosystem II (Fv/Fm), reducing relative electrolyte leakage (REL) and malondialdehyde (MDA), and increasing proline content in overexpressed lines (OEs), which played an active role in cold resistance. Through the overexpression of in and grape calli, the results showed that compared with wild type (WT), transgenic lines had higher antioxidant enzyme activity and proline content, lower REL, MDA, and hydrogen peroxide (HO) content, and an improved ability of scavenging reactive oxygen species. In addition, the expression levels of and genes related to cold response were up-regulated in transgenic lines. To sum up, is actively involved in the cold tolerance of and grape, and has the potential to be a candidate gene for improving plant cold tolerance.
Topics: Arabidopsis; Cold Temperature; Cold-Shock Response; Cyclopentanes; Gene Expression Regulation, Plant; Photosynthesis; Plant Proteins; Plants, Genetically Modified; Vitis
PubMed: 38674041
DOI: 10.3390/ijms25084458 -
Toxics Mar 2024The environmental load by isoxaflutole and its formulated herbicide products has increasingly become apparent because, after the ban of atrazine, isoxaflutole has become...
The environmental load by isoxaflutole and its formulated herbicide products has increasingly become apparent because, after the ban of atrazine, isoxaflutole has become its replacement active ingredient (a.i.). Obtaining information regarding the fate of this a.i. in environmental matrices and its ecotoxicological effects on aquatic organisms is essential for the risk assessment of the herbicide. In this study, the effects of Merlin Flexx- and Merlin WG75 formulated isoxaflutole-based herbicide products and two selected additives (cyprosulfamide safener and 1,2-benzisothiazol-3(2H)-one antimicrobial agent) were investigated on in growth inhibition assays. In ecotoxicological tests, two conventional (optical density and chlorophyll-a content) and two induced fluorescence-based (Fv*/Fp: efficiency of the photosystem PSII and Rfd* changes in the observed ratio of fluorescence decrease) endpoints were determined by UV-spectrophotometer and by our FluoroMeter Module, respectively. Furthermore, dissipation of isoxaflutole alone and in its formulated products was examined by an HPLC-UV method. In ecotoxicological assays, the fluorescence-based Rfd* was observed as the most sensitive endpoint. In this study, the effects of the safener cyprosulfamide and the antimicrobial agent 1,2-benzisothiazol-3(2H)-one on is firstly reported. The results indicated that the isoxaflutole-equivalent toxicity of the mixture of the isoxaflutole-safener-antimicrobial agent triggered lower toxicity (EC = 2.81 ± 0.22 mg/L) compared to the individual effect of the a.i. (EC = 0.02 ± 0.00 mg/L). The Merlin Flexx formulation (EC = 27.04 ± 1.41 mg/L) was found to be approximately 50-fold less toxic than Merlin WG75, which can be explained by the different chemical characteristics and quantity of additives in them. The additives influenced the dissipation of the a.i. in Z8 medium, as the DT value decreased by approximately 1.2- and 3.5-fold under light and dark conditions, respectively.
PubMed: 38668461
DOI: 10.3390/toxics12040238 -
Metabolites Apr 2024Fungicides play an important role in crop protection, but they have also been shown to adversely affect non-target organisms, including those living in the aquatic...
Fungicides play an important role in crop protection, but they have also been shown to adversely affect non-target organisms, including those living in the aquatic environment. The aim of the present study is to combine experimental and computational approaches to evaluate the effects of flutriafol, metconazole, myclobutanil, tebuconazole, tetraconazole and triticonazole on aquatic model organisms and to obtain information on the effects of these fungicides on , a freshwater plant, at the molecular level. The EC (the half-maximum effective concentration) values for the growth inhibition of in the presence of the investigated fungicides show that metconazole (EC = 0.132 mg/L) and tetraconazole (EC = 0.539 mg/L) are highly toxic, tebuconazole (EC = 1.552 mg/L), flutriafol (EC = 3.428 mg/L) and myclobutanil (EC = 9.134 mg/L) are moderately toxic, and triticonazole (EC = 11.631 mg/L) is slightly toxic to this plant. The results obtained with the computational tools TEST, ADMETLab2.0 and admetSAR2.0 also show that metconazole and tetraconazole are toxic to other aquatic organisms: , and . A molecular docking study shows that triazole fungicides can affect photosynthesis in because they strongly bind to C43 (binding energies between -7.44 kcal/mol and -7.99 kcal/mol) and C47 proteins (binding energies between -7.44 kcal/mol and -8.28 kcal/mol) in the reaction center of photosystem II, inhibiting the binding of chlorophyll a to these enzymes. In addition, they can also inhibit glutathione S-transferase, an enzyme involved in the cellular detoxification of .
PubMed: 38668325
DOI: 10.3390/metabo14040197 -
Frontiers in Microbiology 2024Zinc (Zn) is an essential trace element but can lead to water contamination and ecological deterioration when present in excessive amounts. Therefore, investigating the...
Zinc (Zn) is an essential trace element but can lead to water contamination and ecological deterioration when present in excessive amounts. Therefore, investigating the photosynthetic response of microalgae to Zn stress is of great significance. In this study, we assessed the photosynthetic responses of neutrophilic and acidophilic sp. 1710 to Zn exposure for 96 h. The specific growth rate (μ), chlorophyll-a (Chl-a) content, and chlorophyll fluorescence parameters were determined. The results demonstrated that sp. 1710 was much more tolerant to Zn than , with the half-maximal inhibitory concentration (IC50) values of 225.4 mg/L and 23.4 mg/L, respectively. The μ and Chl-a content of decreased in the presence of 15 mg/L Zn, whereas those of sp. 1710 were unaffected by as high as 100 mg/L Zn. Chlorophyll fluorescence parameters indicated that the regulation of energy dissipation, including non-photochemical quenching, played a crucial role in Zn stress resistance for both strains. However, in the case of , non-photochemical quenching was inhibited by 5 mg/L Zn in the first 48 h, whereas for sp. 1710, it remained unaffected under 100 mg/L Zn. sp. 1710 also exhibited a 20 times stronger capacity for regulating the electron transfer rate than under Zn stress. The light energy utilization efficiency (α) of sp. 1710 had the most highly non-linear correlation with μ, indicating the energy utilization and regulation process of sp. 1710 was well protected under Zn stress. Collectively, our findings demonstrate that the photosystem of sp. 1710 is much more resilient and tolerant than that of under Zn stress.
PubMed: 38650883
DOI: 10.3389/fmicb.2024.1383360