Search bioRxiv⌕ Search

SEARCH · Search bioRxiv

Results for “Plant Biology”

Search indexed bioRxiv preprints in genomics, neuroscience, cell biology and bioinformatics. Read source abstracts and check manuscript versions; preprints are not peer reviewed.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources

Using single-plant -omics in the field to link maize genes to functions and phenotypes

Most of our current knowledge on plant molecular biology is based on experiments in controlled lab environments. Over the years, lab experiments have generated substantial insights in the molecular wiring of plant developmental processes, stress responses and phenotypes. However, translating these insights from the lab to the field is often not straightforward, in part because field growth conditions are very different from lab conditions. Here, we test a new experimental design to unravel the molecular wiring of plants and study gene-phenotype relationships directly in the field. We molecularly profiled a set of individual maize plants of the same inbred background grown in the same field, and used the resulting data to predict the phenotypes of individual plants and the function of maize genes. We show that the field transcriptomes of individual plants contain as much information on maize gene function as traditional lab-generated transcriptomes of pooled plant samples subject to controlled perturbations. Moreover, we show that field-generated transcriptome and metabolome data can be used to quantitatively predict at least some individual plant phenotypes. Our results show that profiling individual plants in the field is a promising experimental design that could help narrow the lab-field gap.

systems biology↗

Tagging and harvesting of developing rice spikelets to demarcate grain developmental stages

PremiseIn rice, grain is the major sink for nutrient storage and is a rich source of carbohydrates, seed storage proteins, lipids, minerals, and vitamins, making it a principal food source for over half of the worlds population. Grain development in rice generally spans over a month and has been divided into five stages, S1-S5, depending upon various morphological and physiological changes occurring in the developing seed. To completely understand the process, rice grain development needs to be examined at each stage. However, there are no detailed protocols available to demarcate grain developmental stages. Methods and ResultsThis protocol describes how to tag and harvest the developing rice spikelets. The process starts with anthesis and continues till seed maturation, demarcating the five stages of rice grain development. Seeds are collected, labelled, and stored for use in molecular experiments. Using this protocol, we were able to identify and distinguish different seed developmental stages as observed by histochemical screening. ConclusionThis is an easy, efficient, and cost-effective method. This protocol ensures the collection of the entire panel of rice seed developmental stages. The stored tissue can later be used for various molecular biology based experiments.

plant biology↗

Full-length transcriptome atlas of Panax vietnamensis var. fuscidiscus reveals novel genes and alternative splicing in tissue-specific biosynthesis of ocotillol-type saponins

BackgroundPanax vietnamensis var. fuscidiscus is the only known Panax species that accumulates exceptionally high levels of ocotillol (OCT)-type ginsenosides, particularly majonoside R2. However, the molecular mechanisms underlying OCT-type ginsenoside biosynthesis remain largely uncharacterized, due in part to the absence of comprehensive full-length transcriptome data and complete gene annotations. ResultsWe combined PacBio single-molecule real-time (SMRT) and Illumina RNA sequencing (RNA-Seq) technologies to construct the first tissue-specific, full-length transcriptome atlas of P. vietnamensis var. fuscidiscus. A total of 281,468 non-redundant transcripts were assembled, including 8,089 novel genes not present in existing annotations, substantially expanding the documented gene repertoire of this species. We identified 21 candidate genes putatively involved in triterpenoid saponin biosynthesis and uncovered distinct tissue-specific expression patterns across the oleanane (OA)-, protopanaxadiol (PPD)-, protopanaxatriol (PPT)-, and OCT-type biosynthetic pathways. Notably, we detected 46,917 alternative splicing (AS) events, with over 45% of expressed genes producing multiple isoforms. Several key biosynthetic genes--including dammarenediol synthase (DDS), cytochrome P450 716A53v2 (CYP716A53v2), and mevalonate diphosphate decarboxylase (MVD)--exhibited tissue-specific splicing patterns, such as retained introns and exon skipping, which may contribute to functional diversification of isoforms involved in OCT-type ginsenoside biosynthesis. These results highlight the importance of post-transcriptional regulation and transcript diversity in the evolution and fine-tuning of specialized metabolic pathways. ConclusionsThis study establishes a high-quality, full-length transcriptomic resource for P. vietnamensis var. fuscidiscus, revealing previously undescribed genes and extensive alternative splicing events related to ginsenoside biosynthesis. Our findings provide novel molecular insights into the mechanisms regulating OCT-type saponin accumulation and offer a foundation for future research into the functional characterization, regulatory mechanisms, and synthetic biological production of rare triterpenoid saponins.

plant biology↗

RootPainter: Deep Learning Segmentation of Biological Images with Corrective Annotation

We present RootPainter, a GUI-based software tool for the rapid training of deep neural networks for use in biological image analysis. RootPainter facilitates both fully-automatic and semi-automatic image segmentation. We investigate the effectiveness of RootPainter using three plant image datasets, evaluating its potential for root length extraction from chicory roots in soil, biopore counting and root nodule counting from scanned roots. We also use RootPainter to compare dense annotations to corrective ones which are added during the training based on the weaknesses of the current model.

plant biology↗

Circadian and diel regulation of photosynthesis in the bryophyte Marchantia polymorpha

Circadian rhythms are 24-hour biological cycles that align metabolism, physiology and development with daily environmental fluctuations. Photosynthetic processes are governed by the circadian clock in both flowering plants and some cyanobacteria, but it is unclear how extensively this is conserved throughout the green lineage. We investigated the contribution of circadian regulation to aspects of photosynthesis in Marchantia polymorpha, a liverwort that diverged from flowering plants early in the evolution of land plants. First, we identified in M. polymorpha the circadian regulation of photosynthetic biochemistry, measured using two approaches (delayed fluorescence, PAM fluorescence). Second, we identified that light-dark cycles synchronize the phase of 24 h cycles of photosynthesis in M. polymorpha, whereas the phases of different thalli desynchronize under free running conditions. This might also be due to masking of the underlying circadian rhythms of photosynthesis by light-dark cycles. Finally, we used a pharmacological approach to identify that chloroplast translation might be necessary for clock control of light harvesting in M. polymorpha. We infer that the circadian regulation of photosynthesis are well-conserved amongst terrestrial plants.

plant biology↗

Effects of Abattoir Effluent as Biofertilizer on Pisum sativum Yield

Biological preparation containing live or latent cell of microorganisms or their metabolites, which when inoculated to seed, soil or roots of seedlings, promote plant growth and enhance harvestable yield is termed as Biofertilizers. This research was conducted to determine the growth promoting effect of some selected bacteria on pea plants. A comparative study on the effect of biofertilizers and chemical fertilizers was done on growth parameters in pea plant. An experiment was conducted in Randomized Complex Block Design (RCBD) with three replicates. The treatment were (T1=Control, T2=Biofertilizer, T3=Chemical fertilizer). Biofertilizer used in this study was abattoir effluent and chemical fertilizer was NPK fertilizers. The material consisted of two cultivars of Pisum sativum species. Pea seeds were planted in (21) polythene bags and left to grow to a reasonable height after which different levels of biofertilizers and chemical fertilizers were added. Biofertilizers levels of 50ml, 100ml, 150ml and chemical fertilizer of 1g, 2g and 3g were added respectively, and the procedure was repeated for twelve of the remaining polythene bags to serve as replicates while the last three polythene bags were left without fertilizer application to serve as control plant. The plants were left to develop to maturity after which growth parameters of height, number of leaves, leaf area and plant dry weight were measured for each plant as a determinant of growth. Biofertilizers had the best performance when compare with chemical fertilizers. 100ml of biofertilizers had the highest growth rate and 50ml had the least when compared to the control. Chemical fertilizers had significant difference on height, number of leaves, leaf area and however insignificant on biomass when compared to control pea plant as LSD was greater than mean difference. According to this study using biofertilizer has increased growth and growth component of pea significantly. Biofertilizers level of 100ml should therefore be adopted by farmers so as to get the maximum yield and bioconversion of organic wastes into value added organic/biofertilizers at local level should be done.

plant biology↗

A High-Throughput Extraction and Analysis Method for Steroidal Glycoalkaloids in Tomato

Tomato steroidal glycoalkaloids (tSGAs) are a class of cholesterol-derived metabolites uniquely produced by the tomato clade. These compounds provide protection against biotic stress due to their fungicidal and insecticidal properties. Although commonly reported as being anti-nutritional, both in vitro as well as pre-clinical animal studies have indicated that some tSGAs may have a beneficial impact on human health. However, the paucity of quantitative extraction and analysis methods presents a major obstacle for determining the biological and nutritional functions of tSGAs. To address this problem, we developed and validated the first comprehensive extraction and UHPLC-MS/MS quantification method for tSGAs. Our extraction method allows for up to 16 samples to be extracted simultaneously in 20 minutes with 93.0 {+/-} 6.8% and 100.8 {+/-} 13.1% recovery rates for tomatidine and alpha-tomatine, respectively. Our ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method was able to chromatographically separate analytes derived from 16 tSGAs representing 9 different tSGA masses, as well as two internal standards, in 13 minutes. Tomato steroidal glycoalkaloids that did not have available standards were annotated using high resolution mass spectrometry as well as product ion scans that provided fragmentation data. Lastly, we utilized our method to survey a variety of commonly consumed tomato-based products. Total tSGA concentrations ranged from 0.7 to 3.4 mg/serving and represent some of the first reported tSGA concentrations in tomato-based products. Our validation studies indicate that our method is sensitive, robust, and able to be used for a variety of applications where concentrations of biologically relevant tSGAs need to be quantified.

plant biology↗

Leaky ribosomal scanning enables tunable translation of bicistronic ORFs in green algae.

Advances in sequencing technology have unveiled examples of nucleus-encoded polycistronic genes, once considered rare. Exclusively polycistronic transcripts are prevalent in green algae, although the mechanism by which multiple polypeptides are translated from a single transcript is unknown. Here, we used bioinformatic and in vivo mutational analyses to evaluate competing mechanistic models for polycistronic expression in green algae. High-confidence manually curated datasets of bicistronic loci from two divergent green algae, Chlamydomonas reinhardtii and Auxenochlorella protothecoides, revealed 1) a preference for weak Kozak-like sequences for ORF 1 and 2) an underrepresentation of potential initiation codons before ORF 2, which are suitable conditions for leaky scanning to allow ORF 2 translation. We used mutational analysis in Auxenochlorella protothecoides to test the mechanism. In vivo manipulation of the ORF 1 Kozak-like sequence and start codon altered reporter expression at ORF 2, with a weaker Kozak-like sequence enhancing expression and a stronger one diminishing it. A synthetic bicistronic dual reporter demonstrated inversely adjustable activity of green fluorescent protein expressed from ORF 1 and luciferase from ORF 2, depending on the strength of the ORF 1 Kozak-like sequence. Our findings demonstrate that translation of multiple ORFs in green algal bicistronic transcripts is consistent with episodic leaky ribosome scanning of ORF 1 to allow translation at ORF 2. This work has implications for the potential functionality of upstream open reading frames found across eukaryotic genomes and for transgene expression in synthetic biology applications. Significance StatementTextbook dogma states that nucleus-encoded genes are monocistronic, producing transcripts with a single translated open reading frame. However, highly conserved bicistronic loci are pervasive in green algae that are separated by several hundred million years of evolution, speaking to their ancestral origins and functions within the Chlorophyte lineage. A combination of bioinformatic analysis and in vivo gene manipulation supports leaky ribosomal scanning as the primary mechanism for translation of multiple ORFs from bicistronic transcripts. We have successfully tuned synthesis levels of two proteins encoded on one mRNA by modifying the ORF 1 Kozak-like sequence. These findings may have broad applications in synthetic biology.

plant biology↗

Conserved residues in the wheat (Triticum aestivum) NAM-A1 NAC domain are required for protein binding and when mutated lead to delayed peduncle and flag leaf senescence

BackgroundNAC transcription factors contain five highly conserved subdomains which are required for protein dimerisation and DNA binding. Few residues within these subdomains have been identified as essential for protein function, and fewer still have been shown to be of biological relevance in planta. Here we use a positive regulator of senescence in wheat, NAM-A1, to test the impact of missense mutations at specific, highly conserved residues of the NAC domain on protein function.\n\nResultsWe identified missense mutations in five highly conserved residues of the NAC domain of NAM-A1 in a tetraploid TILLING population. TILLING lines containing these mutations, alongside synonymous and non-conserved mutation controls, were grown under glasshouse conditions and scored for senescence. Four of the five mutations showed a significant and consistent delay in peduncle senescence but had no consistent effects on flag leaf senescence. All four mutant alleles with the delayed senescence phenotype also lost the ability to interact with the homoeolog NAM-B1 in a yeast two-hybrid assay. Two of these residues were previously shown to be involved in NAC domain function in Arabidopsis, suggesting conservation of residue function between species. Three of these four alleles led to an attenuated cell death response compared to wild-type NAM-A1 when transiently over-expressed in Nicotiana benthamiana. One of these mutations was further tested under field conditions, in which there was a significant and consistent delay in both peduncle and leaf senescence.\n\nConclusionsWe combined field and glasshouse studies of a series of mutant alleles with biochemical analyses to identify four residues of the NAC domain which are required for NAM-A1 function and protein interaction. We show that mutations in these residues lead to a gradient of phenotypes, raising the possibility of developing allelic series of mutations for traits of agronomic importance. We also show that mutations in NAM-A1 more severely impact peduncle senescence, compared to the more commonly studied flag leaf senescence, highlighting this as an area deserving of further study. The results from this integrated approach provide strong evidence that conserved residues within the functional domains of NAC transcription factors have biological significance in planta.

plant biology↗

Expressing remorin in animal cells forms filamentous structure unraveling the mechanism of plasmodesmata biogenesis

Plasmodesmata (PD) are crucial structures for intercellular communication in multicellular plants with remorins being their crucial plant-specific structural and functional constituents. The PD biogenesis is an intriguing but poorly understood process. By expressing an Arabidopsis remorin protein in mammalian cells, we have reconstituted a PD-like filamentous structure, termed remorin filament (RF), connecting neighboring cells physically and physiologically. Notably, RFs are capable of transporting macromolecules intercellularly, in a way similar to plant PD. With further super-resolution microscopic analysis and biochemical characterization, we found that RFs are also composed of actin filaments, forming the core skeleton structure, aligned with the remorin protein. This unique heterologous filamentous structure might explain the molecular mechanism for remorin function as well as PD construction. Furthermore, remorin protein exhibits a specific distribution manner in the plasma membrane in mammalian cells, representing a lipid nanodomain, depending on its lipid modification status. Our studies not only provide crucial insights into the mechanism of PD biogenesis, but also uncovers unsuspected fundamental mechanistic and evolutionary links between intercellular communication systems of plants and animals. SignificanceRemorin is rising as a crucial lipid microdomain marker, as well as an essential component of plasmodesmata in plants. However, the biological role of remorin in plants is elusive. With a heterologous system, we found that remorin expression is able to form intercellular filamentous structure, namely remorin filament (RF), connecting neighboring mammalian cells functionally. By employing multiple approaches, we tested the functionality of RFs, as well as investigated their structures. RFs highly resemble plant plasmodesmata, in many ways, such as its morphology, molecular constitutes, and its ability to transport macromolecules intercellularly. Our study provides novel insights into the biogenesis of plasmodesmata and uncovers fundamental evolutionary links in molecular construction of intercellular connections in both plants and animals.

cell biology↗

PsbS confers limited adaptive benefit to C4 photosynthesis under fluctuating light

Adaptation of plant photosynthesis to dynamic light conditions experienced in natural environments is achieved through specific protective mechanisms. Energy-dependent non-photochemical quenching (qE), regulated by Photosystem II Subunit S (PsbS), is a key process facilitating acclimation to fluctuating light in C3 plants, which operate conventional photosynthesis. C4 plants, which include some of the worlds most productive and agriculturally important crops, have evolved a distinct high-efficiency photosynthetic pathway. Little is known about the role of specific processes, like qE, in acclimation of C4 plants to dynamic light environments. We generated gene-edited lines of the model C4 grass Setaria viridis lacking PsbS, which were found to be deficient in qE. This deficiency resulted in a modest increase in PSII photoinhibition and a CO2 assimilation penalty under light stress in short-term experiments, but photosynthesis and growth under fluctuating light were unaffected. Instead, keeping Photosystem I oxidised through photosynthetic control, negative feedback regulation of the Cytochrome b6f complex, was critical. Therefore, unlike in C3 plants, qE does not provide a significant adaptive advantage to C4 plants under dynamic light conditions. These findings provide important insights into the biology of C4 plants and help prioritise future strategies for improving the productivity and resilience of C4 crops.

plant biology↗

Biological activity of Ajuga iva extracts against the African cotton leafworm Spodoptera littoralis

The African cotton leafworm Spodoptera littoralis, a major crop pest worldwide, is controlled by chemical insecticides, leading to serious resistance problems. Ajuga plants contain phytoecdysteroids (analogs of arthropod steroid hormones that regulate metamorphoses) and clerodanes (diterpenoids exhibiting antifeedant activity). We analyzed phytoecdysteroids and clerodanes in leaf extracts of the Israeli Ajuga iva by LC-TOF-MS and TLC, and their efficiency at reducing S. littoralis fitness. Castor bean leaves were smeared with an aqueous suspension of dried methanolic crude extract of phytoecdysteroid and clerodanes from A. iva leaves (50, 100 and 250 {micro}g/{micro}l). First and third instars of S. littoralis larvae were fed with 1 treated leaf for 3 and 4 days, respectively. Mortality, larval weight gain, relative growth rate and survival were compared to feeding on control leaves. To evaluate and localize A. iva crude leaf extract activity in the insect gut, we used DAPI and phalloidin staining. Crude extract of A. iva leaves (50, 100 and 250 {micro}g/{micro}l) significantly increased mortality of first instar S. littoralis larvae (36%, 70% and 87%, respectively) compared to controls (6%). Third instar larval weight gain decreased significantly (by 52%, 44% and 30%, respectively), as did relative growth rate (-0.05 g/g day, compared to the relevant controls). S. littoralis larvae were further affected at later stages, with few survivors. Insect-gut staining showed that 250 {micro}g/{micro}l crude leaf extract reduces gut size, with relocation of nuclei and abnormal actin-filament organization. Our results demonstrate the potential of A. iva extract for alternative, environmentally safe insect-pest control. Key MessageInsects cause severe damage to numerous crops and their control relies on pesticides. Green control is becoming increasingly popular due to concerns about the negative impacts of pesticides on the environment. Phytoecdysteroids are found in Ajuga plants and affect a wide range of insects at very low concentrations. Here we demonstrate that crude extract from Ajuga iva alters the development of Spodoptera littoralis. Phytoecdysteroids may therefore be beneficial in IPM programs.

plant biology↗

Wide sampling of natural diversity identifies novel molecular signatures of C4 photosynthesis

Introductory paragraphMuch of biology is associated with convergent traits, and it is challenging to determine the extent to which underlying molecular mechanisms are shared across phylogeny. By analyzing plants representing eighteen independent origins of C4 photosynthesis, we quantified the extent to which this convergent trait utilises identical molecular mechanisms. We demonstrate that biochemical changes that characterise C4 species are recovered by this process, and expand the paradigm by four metabolic pathways not previously associated with C4 photosynthesis. Furthermore, we show that expression of many genes that distinguish C3 and C4 species respond to low CO2, providing molecular evidence that reduction in atmospheric CO2 was a driver for C4 evolution. Thus the origin and architecture of complex traits can be derived from transcriptome comparisons across natural diversity.

plant biology↗

Simultaneous and Dynamic Super-Resolution Imaging of Two Proteins in Arabidopsis thaliana using dual-color sptPALM

Super-resolution microscopy techniques have revolutionized cell biology by providing insights into single-molecule dynamics and nanoscale organization within living cells. However, the application of dynamic live-cell methods in plants remains limited by the availability of suitable fluorophores for simultaneous visualization of multiple proteins. To address this challenge, we implemented a dual-color single-particle tracking photoactivated localization microscopy (sptPALM) approach based on codon-optimized photoactivatable fluorescent proteins PA-GFP and PATagRFP. Recently, we demonstrated their individual performance in single-color experiments in Nicotiana benthamiana and Arabidopsis thaliana cells. Here, we establish their combined use for dual-color sptPALM, enabling the simultaneous tracking of two distinct protein species within the same plant cell. This approach provides a framework to investigate the coordinated dynamics, interactions, and spatial organization of multiple proteins in living plant cells.

plant biology↗

The draft genome of the invasive walking stick, Medauroidea extradendata, reveals extensive lineage-specific gene family expansions of cell wall degrading enzymes in Phasmatodea

Plant cell wall components are the most abundant macromolecules on Earth. The study of the breakdown of these molecules is thus a central question in biology. Surprisingly, plant cell wall breakdown by herbivores is relatively poorly understood, as nearly all early work focused on the mechanisms used by symbiotic microbes to breakdown plant cell walls in insects such as termites. Recently, however, it has been shown that many organisms make endogenous cellulases. Insects, and other arthropods, in particular have been shown to express a variety of plant cell wall degrading enzymes in many gene families with the ability to break down all the major components of the plant cell wall. Here we report the genome of a walking stick, Medauroidea extradentata, an obligate herbivore that makes uses of endogenously produced plant cell wall degrading enzymes. We present a draft of the 3.3Gbp genome along with an official gene set that contains a diversity of plant cell wall degrading enzymes. We show that at least one of the major families of plant cell wall degrading enzymes, the pectinases, have undergone a striking lineage-specific gene family expansion in the Phasmatodea. This genome will be a useful resource for comparative evolutionary studies with herbivores in many other clades and will help elucidate the mechanisms by which metazoans breakdown plant cell wall components.\n\nData availabilityThe Medauroidea extradentata genome assembly, Med v1.0, is available for download via NCBI (Bioproject: PRJNA369247). The genome, annotation files, and official gene set Mext_OGS_v1.0 are also available at the i5k NAL workspace (https://i5k.nal.usda.gov/medauroidea-extradentata) and at github (https://github.com/pbrec/medauroidea_genome_resources). The genomic raw reads are available via NCBI SRA: SRR6383867 and the raw transcriptomic reads are available at NCBI SRA: SRR6383868, SRR6383869.

genomics↗

A hierarchical transcriptional network controls appressorium-mediated plant infection by the rice blast fungus Magnaporthe oryzae

Rice blast is a pervasive and devastating disease that threatens rice production across the world. In spite of its importance to global food security, however, the underlying biology of plant infection by the blast fungus Magnaporthe oryzae remains poorly understood. In particular, it is unclear how the fungus elaborates a specialised infection cell, the appressorium, in response to surface signals from the rice leaf. Here, we report the identification of a network of temporally co-regulated transcription factors that act downstream of the Pmk1 mitogen-activated protein kinase pathway to regulate gene expression during appressorium-mediated plant infection. We have functionally characterised this network of transcription factors and demonstrated the operation of a hierarchical transcriptional control system. We show that this tiered regulatory mechanism involves Pmk1-dependent phosphorylation of the Hox7 homeobox transcription factor, which represses hyphal-associated gene expression and simultaneously induces major physiological changes required for appressorium development, including cell cycle arrest, autophagic cell death, turgor generation and melanin biosynthesis. Mst12 then regulates gene functions involved in septin-dependent cytoskeletal re-organisation, polarised exocytosis and effector gene expression necessary for plant tissue invasion.

microbiology↗

A Comprehensive UHPLC-MS/MS and Extraction Method for Spinach (Spinacia oleracea) Flavonoids

Spinach produces an array of unique flavonoids not commonly found in other fruits and vegetables. These molecules likely serve as defense agents against biotic and abiotic stress and may have health beneficial properties for humans. Current methods to analyze spinach flavonoids are incomplete and only capture a portion of this uncharacterized pathway. A comprehensive analysis method is needed to determine how genetics, environmental conditions, and other factors influence spinach flavonoid biosynthesis. We developed and validated a high-throughput extraction and ultra high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method to separate and quantify 39 spinach flavonoid species in 11.5 minutes. Spinach flavonoids without authentic standards were putatively identified using MS/MS fragmentation experiments, precursor scans, and matches to high-resolution MS literature reports. Our extraction method enables up to 48 samples to be extracted in 60 minutes with recovery estimates between 100.5 - 107.8%. To assess the suitability of our method and generate benchmark estimates for 39 spinach flavonoids, we grew a panel of 30 genetically diverse spinach accessions and compared quantification data generated with a traditional or our high-throughput approach. Data generated by either approach were comparable, estimating total flavonoid averages of 75.1 - 170.1 or 93.1 - 187.26 mg/100 g fresh weight for the high-throughput and traditional method, respectively. Many estimates generated by our analysis method represent the first quantitative literature reports of these compounds. These experiments indicate that our extraction and analysis method is efficient, robust, and an important tool needed to study the biosynthesis and biological role of spinach flavonoids.

plant biology↗

Compatibility and Multi-Season Field Evaluation of Trichoderma koningiopsis Integrated with Fungicides for Soybean Charcoal Rot Management

Soybean (Glycine max [L.] Merr.) productivity is frequently compromised by soil-borne pathogens. Macrophomina phaseolina (Mp), the causal agent of charcoal rot, can produce important soybean yield losses especially when hot and dry weather prevails. Integrating biological control agents with chemical seed treatments represents a promising strategy for improving disease management. This study aimed to (i) assess the in vitro compatibility of Trichoderma koningiopsis with commercial fungicide seed treatments, and (ii) evaluate the field performance of T. koningiopsis, alone or combined with compatible fungicides, across three soybean growing seasons. Compatibility assays revealed fungicide-specific effects, with Acronis(R) classified as non-fungitoxic and Topseed Extra as moderately fungitoxic. Across field seasons, Mp inoculation reduced seedling emergence, while several seed treatments improved emergence compared to the inoculated control, however, treatment effects varied markedly among years. Disease severity did not differ significantly among treatments in any season, and yield responses were strongly modified by environmental conditions rather than treatment effects. Temperature-response assays showed that T. koningiopsis exhibited optimal growth between 28 to 30{degrees}C and complete inhibition above 40{degrees}C, indicating high thermal sensitivity. The results demonstrate that T. koningiopsis can be integrated with compatible fungicides and may enhance early stand establishment under favorable conditions, but its field performance is strongly limited by high temperatures. These findings highlight the importance of environmental conditions when biological seed treatments are used.

plant biology↗