Course Of Plant Development Research Articles

Growing Maize Root: Lectins Involved in Consecutive Stages of Cell Development

Proteins that carry specific carbohydrate-binding lectin domains have a great variety and are ubiquitous across the plant kingdom. In turn, the plant cell wall has a complex carbohydrate composition, which is subjected to constant changes in the course of plant development. In this regard, proteins with lectin domains are of great interest in the context of studying their contribution to the tuning and monitoring of the cell wall during its modifications in the course of plant organ development. We performed a genome-wide screening of lectin motifs in the Zea mays genome and analyzed the transcriptomic data from five zones of primary maize root with cells at different development stages. This allowed us to obtain 306 gene sequences encoding putative lectins and to relate their expressions to the stages of root cell development and peculiarities of cell wall metabolism. Among the lectins whose expression was high and differentially regulated in growing maize root were the members of the EUL, dirigent–jacalin, malectin, malectin-like, GNA and Nictaba families, many of which are predicted as cell wall proteins or lectin receptor-like kinases that have direct access to the cell wall. Thus, a set of molecular players was identified with high potential to play important roles in the early stages of root morphogenesis.

Targeted Knockout of Eukaryotic Translation Initiation Factor 4E Confers Bymovirus Resistance in Winter Barley.

The Eukaryotic Translation Initiation Factor 4E (EIF4E) is a well-known susceptibility factor for potyvirus infections in many plant species. The barley yellow mosaic virus disease, caused by the bymoviruses Barley yellow mosaic virus (BaYMV) and Barley mild mosaic virus (BaMMV), can lead to yield losses of up to 50% in winter barley. In autumn, the roots of young barley plants are infected by the soil-borne plasmodiophoraceous parasite Polymyxa graminis L. that serves as viral vector. Upon viral establishment and systemic spreading into the upper parts of the plants, yellow mosaics occur as first symptoms on leaves. In the further course of plant development, the disease entails leaf necrosis and increased susceptibility to frost damage. Thanks to the rym4 and rym5 allelic variants of the HvEIF4E gene, more than two thirds of current European winter barley cultivars are resistant to BaYMV and BaMMV. However, several strains of BaYMV and BaMMV have already overcome rym4- and rym5-mediated resistance. Accordingly, new resistance-conferring alleles are needed for barley breeding. Therefore, we performed targeted mutagenesis of the EIF4E gene by Cas9 endonuclease in BaMMV/BaYMV-susceptible winter barley cv. “Igri”. Small insertions were generated, resulting in a shift of the translational reading frame, thereby causing the loss-of-function of EIF4E. The mutations occurred in the homozygous state already in the primary mutants. Their progeny proved invariably homozygous and fully resistant to mechanical inoculation with BaMMV. EIF4E knockout plants showed normal growth habit and produced grains, yet exhibited a yield penalty.

Evidence of nutrient translocation in response to smoke exposure by the East African ant acacia, Vachellia drepanolobium.

Fire is a major selective force on arid grassland communities, favoring traits such as the smoke‐induced seed germination response seen in a wide variety of plant species. However, little is known about the relevance of smoke as a cue for plants beyond the seedling stage.We exposed a fire‐adapted savanna tree, Vachellia (=Acacia) drepanolobium, to smoke and compared nutrient concentrations in leaf and root tissues to unexposed controls. Experiments were performed on three age cohorts: 2‐year‐old, 9‐month‐old, and 3‐month‐old plants.For the 2‐year‐old plants exposed to smoke, carbon and nitrogen concentrations were lower in the leaves and higher in the roots than controls. Less pronounced trends were found for boron and magnesium.In contrast, smoke‐exposed 3‐month‐old plants had lower root nitrogen concentrations than controls. No significant differences were found in the 9‐month‐old plants, and no significant shifts in other nutrient concentrations were observed between plant tissues for any of the three age cohorts. Synthesis: Our findings are consistent with smoke‐induced translocation of nutrients from leaves to roots in 2‐year‐old V. drepanolobium. This could represent a novel form of fire adaptation, with variation over the course of plant development. The translocation differences between age cohorts highlight the need to investigate smoke response in older plants of other species. Accounting for this adaptation could better inform our understanding of savanna community structure and nutrient flows under fire regimes altered by anthropogenic land use and climate change.

Root exudates drive soil-microbe-nutrient feedbacks in response to plant growth.

Although interactions between plants and microbes at the plant-soil interface are known to be important for plant nutrient acquisition, relatively little is known about how root exudates contribute to nutrient exchange over the course of plant development. In this study, root exudates from slow- and fast-growing stages of Arabidopsis thaliana plants were collected, chemically analysed and then applied to a sandy nutrient-depleted soil. We then tracked the impacts of these exudates on soil bacterial communities, soil nutrients (ammonium, nitrate, available phosphorus and potassium) and plant growth. Both pools of exudates shifted bacterial community structure. GeoChip analyses revealed increases in the functional gene potential of both exudate-treated soils, with similar responses observed for slow-growing and fast-growing plant exudate treatments. The fast-growing stage root exudates induced higher nutrient mineralization and enhanced plant growth as compared to treatments with slow-growing stage exudates and the control. These results suggest that plants may adjust their exudation patterns over the course of their different growth phases to help tailor microbial recruitment to meet increased nutrient demands during periods demanding faster growth.

Soil potassium is correlated with root secondary metabolites and root-associated core bacteria in licorice of different ages.

AimsLicorice (Glycyrrhiza uralensis Fisch.) is a crucial medicinal herb as it accumulates glycyrrhizin and liquiritin in roots. Licorice root-associated bacterial communities shaped by soil characteristics are supposed to regulate the accumulation of root secondary metabolites.MethodsThe soil characteristics, root secondary metabolites, and root-associated bacterial communities were analyzed in licorice plants of different ages to explore their temporal dynamics and interaction mechanisms.ResultsTemporal variation in soil characteristics and root secondary metabolites was distinct. The alpha-diversity of root-associated bacterial communities decreased with root proximity, and the community composition was clustered in the rhizosphere. Different taxa that were core-enriched from the dominant taxa in the bulk soil, rhizosphere soil, and root endosphere displayed varied time–decay relationships. Soil total potassium (TK) as a key factor regulated the temporal variation in some individual taxa in the bulk and rhizosphere soils; these taxa were associated with the adjustment of root secondary metabolites across different TK levels.ConclusionsLicorice specifically selects root-associated core bacteria over the course of plant development, and TK is correlated with root secondary metabolites and individual core-enriched taxa in the bulk and rhizosphere soils, which may have implications for practical licorice cultivation.Electronic supplementary materialThe online version of this article (10.1007/s11104-020-04692-0) contains supplementary material, which is available to authorized users.

Expression of cellulose synthase-like genes in two phenotypically distinct flax (Linum usitatissimum L.) subspecies

Cellulose synthase-like (CSL) genes encode glycosyltransferases thought to be involved in the biosynthesis of cell wall non-cellulosic polysaccharides; however, the exact function is not established yet for many of them. We performed a bioinformatics search of CSL genes in the flax genome, their phylogenetic analysis and evaluated expression of CSL genes in the course of plant development and in various plant parts. Quantitative RT-PCR was used to examine expression of CSL genes in several fiber-containing samples of two flax subspecies at seedlings, rapid growth and budding stages. One of the studied subspecies is fiber flax (cultivar Blakit) that was developed to produce high-quality fiber and another one is dehiscent flax that is not used for fiber production. Our study has revealed that the LusCSLD3 and LusCSLG3.2/3.3 genes were highly expressed in all studied samples and their expression was comparable with the expression of cellulose synthase genes involved in secondary cell wall development (LusCESA4 and LusCESA7-B) at rapid growth and budding stages. LusCSLB4 gene had a strong expression in seedling samples only. We have found that LusCSL gene expression profiles from the two phenotypically distinct flax subspecies are more different at the seedling stage than at the later developmental stages—expression of LusCSL was higher in fiber flax Blakit at the seedling stage as compared to dehiscent flax. Analysis of data from RNA-Seq experiments performed on various parts of flax plants revealed that LusCSLG with unknown substrate activity could be a specific glycosyltransferase involved in the synthesis of a non-cellulosic polysaccharide composing the fiber cell wall. Our findings lay the foundation for the understanding of the fiber cell-wall biogenesis and suggest characteristic features of this process in the cultivated flax.

Chemical defense over decadal scales: Ontogenetic allocation trajectories and consequences for fitness in a foundation tree species

Abstract Expression of herbivore defense traits can change dramatically during the course of plant development. Little is known, however, about the degree of genetic or sexual variation in these ontogenetic defense trajectories or whether the trajectories themselves are adaptive, especially in long‐lived species. We used a 13‐year dataset of chemical defense traits, growth and survivorship from a common garden of trembling aspen (Populus tremuloides) genotypes to document long‐term defense trajectories and their relationship to tree fitness during juvenile and early mature stages. Overall, concentrations of the two principal classes of aspen defense compounds (salicinoid phenolic glycosides [SPGs] and condensed tannins [CTs]) decreased to differing degrees in foliage of juvenile trees and then remained relatively constant in maturity. Initial values, juvenile rates of change and average mature values all exhibited significant genetic variation for both SPGs and CTs. Relationships between defense trajectory parameters and metrics of tree fitness (growth and survivorship) depended on compound type and tree sex. Females with higher‐allocation SPG trajectories (high initial juvenile concentrations, slow juvenile declines, high mature concentrations) grew more slowly relative to females with lower‐allocation trajectories. In males, higher‐allocation SPG trajectories had a lesser effect on growth but were associated with reduced mortality. Juvenile CT trajectories were not correlated with tree fitness, but average CT concentration in maturity was positively related to growth in females. These results suggest that ontogenetic defense trajectories are adaptive and subject to natural selection. Genotypic variation and ontogeny shape tree defensive chemistry, both independently and interactively. These patterns of defense expression have the potential to structure trophic interactions and the genetic composition of forests in both space and time. A free Plain Language Summary can be found within the Supporting Information of this article.

Chemical and isotopic markers detect water deficit and its influence on nutrient allocation in Phaseolus vulgaris.

The impact of drought on plant growth and yield has been widely studied and is considered a major limitation to crops reaching yield potential. Less known is the impact of water deficit on the nutritional quality of the resulting yield. This study characterised the impact of water deficit on carbon assimilation, modelled water use efficiency from carbon isotope discrimination and analysed the concentration of mineral nutrients, amino acids and sugars in leaf, phloem and pod pools collected from Phaseolus vulgaris L. (common bean) grown in a controlled environment. Water deficit led to an isohydric response, impacting on carbon isotope abundance in all tissues though not translating to any significant treatment differences in water use efficiency or nutrient content in tissues over the course of plant development. The results obtained in this study demonstrate that nutrient content of P. vulgaris yield was not impacted by the availability of water. The absence of significant changes in the nutrient content of individual seeds highlights the plasticity of developing reproductive tissue to changes in whole plant water availability.

The Unfolded Protein Response Supports Plant Development and Defense as well as Responses to Abiotic Stress.

The unfolded protein response (UPR) is a stress response conserved in eukaryotic organisms and activated by the accumulation of misfolded proteins in the endoplasmic reticulum (ER). Adverse environmental conditions disrupt protein folding in the ER and trigger the UPR. Recently, it was found that the UPR can be elicited in the course of plant development and defense. During vegetative plant development, the UPR is involved in normal root growth and development, the effect of which can be largely attributed to the influence of the UPR on plant hormone biology. The UPR also functions in plant reproductive development by protecting male gametophyte development from heat stress. In terms of defense, the UPR has been implicated in virus and microbial defense. Viral defense represents a double edge sword in that various virus infections activate the UPR, however, in a number of cases, the UPR actually supports viral infections. The UPR also plays a role in plant immunity to bacterial infections, again through the action of plant hormones in regulating basal immunity responses.

LIGNOHUMATE: LITTLE EXPENSES, MANY VEGETABLES

Humic compounds occupy the important place in the chain plant – water. Their application in technologies for vegetable plant growing with the use of drip irrigation enables to increase the coefficient of nutrient compound assimilation from soil with applied fertilizers. The preparation ‘Lighohumate’ presented in the article is integrated fertilizer, possessing the properties of anti-stress, immunomodulator and sticking agent. This preparation has the highest content of humic acids to 20% for liquid and to 90% for dried, consequently it has a powerful influence on plant organism, opening hidden biological reserves, and improving the crop productivity. The experimental tests showed that ‘Lighohumate’ application trough drip irrigation system together with foliage fertilizers had given significant yield augmentation; 5-20% depending on medium and technology in vegetable crops cultivated with different agricultural techniques. The permanent speeding-up from 3 to 12 days was noticed in the course of plant development with increase of early yield outcome. ‘Lighohumate’ can be used as seed treatment agent as well as foliage fertilizer and already applied giving a result in many vegetable production enterprises.

Feed protein value of acidic precipitates obtained from press juices of three types of green forage leaves

The present study investigated the potential of three types of green forage leaves for the extraction of a protein rich precipitate. Samples were taken during calendar weeks 19, 21 and 23 of 2012 from three grass rich pastures (GRP), two legume rich pastures (LRP) and one Trifolium pratense (TP) monoculture around the City of Freising (Germany) (n=9, n=6 and n=3 samples of GRP, LRP and TP). Trifolium pratense and LRP yielded the highest average amounts of precipitate per kg fresh leaf material. The highest amounts of crude protein (CP) within the precipitate were obtained from TP and GRP. Contents of essential and non-essential amino acids (AA) were highest within the precipitates of TP. The extraction efficiency as expressed by total precipitate yield, precipitate CP as well as the amounts of essential and non-essential AA declined in the course of plant development. The amounts of essential AA relative to total AA within the obtained precipitates were in most cases comparable or even higher than average amounts in soybean meal (480g CP/kg fresh matter). Taken together, we were able to extract a CP rich precipitate from green forage leafs. Products of that kind represent a valuable protein source and may replace soybean meal to some extent in practical livestock diets.

The role of invertases in plant compensatory responses to simulated herbivory.

BackgroundThe ability of a plant to overcome animal-induced damage is referred to as compensation or tolerance and ranges from undercompensation (decreased fitness when damaged) to overcompensation (increased fitness when damaged). Although it is clear that genetic variation for compensation exists among plants, little is known about the specific genetic underpinnings leading to enhanced fitness. Our previous study identified the enzyme GLUCOSE-6-PHOSPHATE DEHYDROGENASE 1 (G6PD1) as a key regulator contributing to the phenomenon of overcompensation via its role in the oxidative pentose phosphate pathway (OPPP). Apart from G6PD1 we also identified an invertase gene which was up-regulated following damage and that potentially integrates with the OPPP. The invertase family of enzymes hydrolyze sucrose to glucose and fructose, whereby the glucose produced is shunted into the OPPP and presumably supports plant regrowth, development, and ultimately compensation. In the current study, we measured the relative expression of 12 invertase genes over the course of plant development in the Arabidopsis thaliana genotypes Columbia-4 and Landsberg erecta, which typically overcompensate and undercompensate, respectively, when damaged. We also compared the compensatory performances of a set of invertase knockout mutants to the Columbia-4 wild type.ResultsWe report that Columbia-4 significantly up-regulated 9 of 12 invertase genes when damaged relative to when undamaged, and ultimately overcompensated for fruit production. Landsberg erecta, in contrast, down-regulated two invertase genes following damage and suffered reduced fitness. Knockout mutants of two invertase genes both exhibited significant undercompensation for fruit production, exhibiting a complete reversal of the wild type Col-4’s overcompensation.ConclusionCollectively, these results confirm that invertases are essential for not only normal plant growth and development, but also plants’ abilities to regrow and ultimately compensate for fitness following apical damage.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-015-0655-6) contains supplementary material, which is available to authorized users.

Evolutionary aspects of non-cell-autonomous regulation in vascular plants: structural background and models to study.

Plasmodesmata (PD) serve for the exchange of information in form of miRNA, proteins, and mRNA between adjacent cells in the course of plant development. This fundamental role of PD is well established in angiosperms but has not yet been traced back to the evolutionary ancient plant taxa where functional studies lag behind studies of PD structure and ontogenetic origin. There is convincing evidence that the ability to form secondary (post-cytokinesis) PD, which can connect any adjacent cells, contrary to primary PD which form during cytokinesis and link only cells of the same lineage, appeared in the evolution of higher plants at least twice: in seed plants and in some representatives of the Lycopodiophyta. The (in)ability to form secondary PD is manifested in the symplasmic organization of the shoot apical meristem (SAM) which in most taxa of seedless vascular plants differs dramatically from that in seed plants. Lycopodiophyta appear to be suitable models to analyze the transport of developmental regulators via PD in SAMs with symplasmic organization both different from, as well as analogous to, that in angiosperms, and to understand the evolutionary aspects of the role of this transport in the morphogenesis of vascular plant taxa.

Three California annual forbs show little response to neighbor removal

In semi-arid systems, competition among plants has limited effects on performance compared to facilitative interactions and abiotic factors. However, the balance between competition and facilitation can change over the course of plant development. Determining when each interaction is important for plant productivity allows us to identify factors limiting plant growth. In this field study, neighbor removal mid-way through the growing season did not result in a size change for any species (Clarkia purpurea, Plantago erecta, and Micropus californicus) in the first year. In the second year, two species had greater biomass when neighbors were removed very early in the growing season, indicating a competitive effect. The third species neither benefited nor suffered from neighbor removal. In some years, P. erecta and M. californicus may be negatively affected by competition at early growth stages and are later unable to capitalize on newly-available resources after removals of competitors. This study shows that early-stage competition can drive biomass production in some annual plants, even in semi-arid systems.

Steroidal glycoalkaloids in Solanum chacoense

Potato (Solanum tuberosum L.), a domesticated species that is the fourth most important world agricultural commodity, requires significant management to minimize the effects of herbivore and pathogen damage on crop yield. A wild relative, Solanum chacoense Bitt., has been of interest to plant breeders because it produces an abundance of novel steroidal glycoalkaloid compounds, leptines and leptinines, which are particularly effective deterrents of herbivory by the Colorado potato beetle (Leptinotarsa decemlineata Say). Biochemical approaches were used in this study to investigate the formation and accumulation of SGAs in S. chacoense. SGA contents were determined in various organs at different stages of organ maturity during a time course of plant development. Leptines and leptinines were the main contributors to the increased levels in SGA concentration measured in the aerial versus the subterranean organs of S. chacoense accession 8380-1. Leptines were not detected in aboveground stolons until the stage where shoots had formed mature chlorophyllous leaves. To gain insights into SGA biosynthesis, the abundance of SGAs and steady-state transcripts of genes coding for enzymes of the central terpene and SGA-specific pathways in various plant organs at anthesis were compared. For two genes of primary terpene metabolism, transcript and SGA abundances were correlated, although with some discrepancies. For genes associated with SGA biosynthesis, transcripts were not detected in some tissues containing SGAs; however these transcripts were detected in the progenitor tissues, indicating the possibility that under our standard growth conditions, SGA biosynthesis is largely limited to highly proliferative tissues such as shoot, root and floral meristems.

Electrophoretic pattern of the polypeptide component in the tight DNA-protein complexes in rat and chicken tissues and its partial characterisation in rat liver

Electrophoretic pattern of the polypeptide component in the tight DNA-protein complexes in rat and chicken tissues and its partial characterisation in rat liverTightly bound to DNA proteins (TBP) are a protein group that remain attached to DNA with covalent or non-covalent bonds after its deproteinisation. The distribution of TBP in genes reflects the type of cell differentiation. It has been hypothesised that TBP binding is involved in regulation of gene expression. Early studies reported uniformity of the TBPs from different sources. Later it was shown that TBPs obtained from DNA, isolated in mild conditions from evolutionary distant species, are different. Application of chloroform DNA extraction without use of externally added enzymes enabled us to reveal differences in the TBP spectrum in plant organs and changes of this spectrum in the course of plant development. The goal of this work was to study the electrophoretic pattern of the polypeptide component in the tight DNA-protein complexes in organs of animals: a mammal (rat) and a bird (chicken). Rat thymus TBPs were represented by 70 and 60 kDa proteins, and the same polypeptides were observed also in brain and skeletal muscles. Kidney TBPs were represented by 85, 70, 65, 60 and 37 kDa polypeptides; 85, 77, 70, 60, 50 and 37 kDa TBPs were characteristic of liver. Numerous minor peptides were observed in all samples studied. The spectrum of chicken liver and blood TBPs differed in distribution of proteins of 25-35 kDa. Mass-spectrometry of 14 bands from rat liver TBP gel revealed 43 different proteins. Chromatin modifying proteins and repair enzymes, transcription factors, serpins, ATPase, kinases and enzymes of ubiquitin-proteasome pathway were found among the TBPs. Thus, TBPs appear to be a vast protein group involved in several intranuclear processes. It is hypothesised that numerous functions ascribed to the nuclear matrix are performed in the TBP complexes.

Plant developmental genetics: Integrating data from different experiments in databases

Plant developmental genetics as a scientific discipline integrates data from such different fields of biology as embryology, plant anatomy, molecular biology and genetics, and studies their interactions in the course of plant development. To date, traditional publication of scientific studies in articles is supplemented by presenting in databases the data generated by high-throughoutput methods in genomics, transcriptomics, proteomics, and phenomics. The information burst, caused both by genome-scale research projects and growth in the number of articles, requires the development of general standards of annotating data from different sources for their integration and comparison. In this review, we present classification and analysis of existing databases, in which the user can find various data on plant developmental genetics, and discuss problems of these data integration both within informational resources and among them.

CYP86B1 Is Required for Very Long Chainω-Hydroxyacid andα,ω-Dicarboxylic Acid Synthesis in Root and Seed Suberin Polyester

Suberin composition of various plants including Arabidopsis (Arabidopsis thaliana) has shown the presence of very long chain fatty acid derivatives C20 in addition to the C16 and C18 series. Phylogenetic studies and plant genome mining have led to the identification of putative aliphatic hydroxylases belonging to the CYP86B subfamily of cytochrome P450 monooxygenases. In Arabidopsis, this subfamily is represented by CYP86B1 and CYP86B2, which share about 45% identity with CYP86A1, a fatty acid omega-hydroxylase implicated in root suberin monomer synthesis. Here, we show that CYP86B1 is located to the endoplasmic reticulum and is highly expressed in roots. Indeed, CYP86B1 promoter-driven beta-glucuronidase expression indicated strong reporter activities at known sites of suberin production such as the endodermis. These observations, together with the fact that proteins of the CYP86B type are widespread among plant species, suggested a role of CYP86B1 in suberin biogenesis. To investigate the involvement of CYP86B1 in suberin biogenesis, we characterized an allelic series of cyp86B1 mutants of which two strong alleles were knockouts and two weak ones were RNA interference-silenced lines. These root aliphatic plant hydroxylase lines had a root and a seed coat aliphatic polyester composition in which C22- and C24-hydroxyacids and alpha,omega-dicarboxylic acids were strongly reduced. However, these changes did not affect seed coat permeability and ion content in leaves. The presumed precursors, C22 and C24 fatty acids, accumulated in the suberin polyester. These results demonstrate that CYP86B1 is a very long chain fatty acid hydroxylase specifically involved in polyester monomer biosynthesis during the course of plant development.

Manifestation and inheritance of tpd1 phenotype in the tobacco insertion mutant with extended flowering period

The tpd1 (from tobacco pollen development 1) insertion mutant of tobacco (Nicotiana tabacum L., cv. Samsun) with extended flowering period was investigated in detail in the course of plant development, and the inheritance of the mutant phenotype was established. The wild-type and mutant plants did not differ in basic developmental indices until the floral transition; later they diverged in the characteristics of male reproductive organs, particularly in anther development and pollen maturation. The pollen of tpd1 plants was underdeveloped and sterile, resulting in a characteristic seedless phenotype with extended flowering period. When mutant flowers were pollinated with wild-type pollen, the tpd1 phenotype was maintained in at least two seed generations, indicating that this trait was heritable. The tpd1 phenotype was closely linked with kanamycin resistance; it follows that the developmental anomalies observed in our experiments immediately depended on the vector DNA insert. Our data presume that tpd1 is a rare dominant monogenic mutation with a narrowly directed physiological manifestation. A model is presented to describe the effect of TPD1. The tpd1 mutant would help identify and clone the new TPD1 gene crucial for viable pollen development.

Holy alliances?

Holy alliances?