Suppression of weed and insect populations by living and straw mulches in sesame (Sesamum indicum L.).

In order to evaluate the effect of different weed management treatments on weeds, pest and natural enemies populations in sesame (Sesamum indicum L.), a 2-year study was conducted in East Azarbaijan, Iran in 2020-2021. The study was conducted based on randomized complete block design with four replications. The weed management treatments consisted of trifluralin use (960 g ai ha-1), wheat straw mulch (WSM), living mulches of fenugreek (Trigonella foenum-graecum L.) (FLM), bitter vetch (Vicia ervilia L.) (VLM), calendula (Calendula officinalis L.) (CLM) and one-time hand weeding (OHW). The effect of weed management treatment was significant on densities of insect pests, natural enemies and weed and also weed biomass and sesame seed yield. The lowest densities of insect pests including Myzus persicae, Brevicoryne brassicae, Helicoverpa armigera and Spodoptera exigua were observed in CLM treatment. Also, the highest densities of natural enemies Coccinella septompunctata, Coccinella undecimpunctata and Orius niger were observed in CLM treatment. The highest reductions in grass (51.0%), broadleaf (72.0%), and total (62.6%) weed biomasses and highest seed yield (1456 kg ha-1) were obtained in OHW. The seed yields in CLM and WSM treatments were not significantly different with trifluralin treatment and could be recommended in sustainable production of sesame.

Griseofulvin Inhibits Root Growth by Targeting Microtubule-Associated Proteins Rather Tubulins in Arabidopsis.

Griseofulvin was considered an effective agent for cancer therapy in past decades. Although the negative effects of griseofulvin on microtubule stability are known, the exact target and mechanism of action in plants remain unclear. Here, we used trifluralin, a well-known herbicide targeting microtubules, as a reference and revealed the differences in root tip morphology, reactive oxygen species production (ROS), microtubule dynamics, and transcriptome analysis between Arabidopsis treated with griseofulvin and trifluralin to elucidate the mechanism of root growth inhibition by griseofulvin. Like trifluralin, griseofulvin inhibited root growth and caused significant swelling of the root tip due to cell death induced by ROS. However, the presence of griseofulvin and trifluralin caused cell swelling in the transition zone (TZ) and meristematic zone (MZ) of root tips, respectively. Further observations revealed that griseofulvin first destroyed cortical microtubules in the cells of the TZ and early elongation zone (EZ) and then gradually affected the cells of other zones. The first target of trifluralin is the microtubules in the root MZ cells. Transcriptome analysis showed that griseofulvin mainly affected the expression of microtubule-associated protein (MAP) genes rather than tubulin genes, whereas trifluralin significantly suppressed the expression of αß-tubulin genes. Finally, it was proposed that griseofulvin could first reduce the expression of MAP genes, meanwhile increasing the expression of auxin and ethylene-related genes to disrupt microtubule alignment in root tip TZ and early EZ cells, induce dramatic ROS production, and cause severe cell death, eventually leading to cell swelling in the corresponding zones and inhibition of root growth.

A dinitroaniline herbicide resistance mutation can be nearly lethal to plants.

BACKGROUND: Lolium rigidum is the most important weed in Australian agriculture and pre-emergence dinitroaniline herbicides (e.g., trifluralin) are widely and persistently used for Lolium control. Consequently, evolution of resistance to dinitroaniline herbicides has been increasingly reported. Resistance-endowing target-site α-tubulin gene mutations are identified with varying frequency. This study investigated the putative fitness cost associated with the common resistance mutation Val-202-Phe and the rare resistance mutation Arg-243-Met causing helical plant growth. RESULTS: Results showed a deleterious effect of Arg-243-Met on fitness when plants are homozygous for this mutation. This was evidenced as high plant mortality, severely diminished root and aboveground vegetative growth (lower relative growth rate), and very poor fecundity compared with the wild-type, which led to a nearly lethal fitness cost of >99.9% in competition with a wheat crop. A fitness penalty in vegetative growth was evident, but to a much lesser extent, in plants heterozygous for the Arg-243-Met mutation. By contrast, plants possessing the Val-202-Phe mutation exhibited a fitness advantage in vegetative and reproductive growth. CONCLUSION: The α-tubulin mutations Arg-243-Met and Val-202-Phe have contrasting effects on fitness. These results help understand the absence of plants homozygous for the Arg-243-Met mutation and the high frequency of plants carrying the Val-202-Phe mutation in dinitroaniline-resistant L. rigidum populations. The α-tubulin Arg-243-Met mutation can have an exceptional fitness cost with nearly lethal effects on resistant L. rigidum plants. © 2022 Society of Chemical Industry.

Understanding Resistance Mechanisms to Trifluralin in an Arkansas Palmer Amaranth Population.

Amaranthus palmeri S. Watson (Palmer amaranth) is considered a problematic and troublesome weed species in many crops in the USA, partly because of its ability to evolve resistance to herbicides. In this study, we explored the mechanism of resistance in a trifluralin-resistant A. palmeri accession collected from Arkansas, USA. Dose-response assays using agar plates demonstrated an EC50 (effective concentration that reduces root length by 50%) of 1.02 µM trifluralin compared to 0.39 µM obtained in the susceptible accession. Thus, under these conditions, the resistant accession required 2.6 times more trifluralin to inhibit root length by 50%. Seeds in the presence or absence of the cytochrome P450-inhibitior malathion displayed a differential response with no significant influence on root length, suggesting that resistance is not P450-mediated. In addition, application of 4-chloro-7-nitrobenzofurazan (NBD-Cl), a glutathione S-transferase (GST) inhibitor, showed significant differences in root length, indicating that GSTs are most likely involved in the resistance mechanism. Sequencing of α- and ß-tubulin genes revealed no single nucleotide polymorphisms (SNPs) previously described between accessions. In addition, relative gene copy number of α- and ß-tubulin genes were estimated; however, both resistant and susceptible accessions displayed similar gene copy numbers. Overall, our results revealed that GST-mediated metabolism contributes to trifluralin resistance in this A. palmeri accession from Arkansas.

Loss of trifluralin metabolic resistance in Lolium rigidum plants exposed to prosulfocarb recurrent selection.

BACKGROUND: Resistance to the dinitroaniline herbicide trifluralin in Lolium rigidum (annual ryegrass) often is mediated by the enhanced capacity to metabolize the herbicide to less toxic polar conjugates and/or by functionally recessive target-site mutations in α-tubulin. RESULTS: In two L. rigidum populations possessing enhanced trifluralin metabolism, resistance was largely reversed by recurrent selection with the thiocarbamate herbicide prosulfocarb (i.e. plant survival was two- to >20-fold lower). Their ability to metabolize trifluralin was significantly decreased (by ≈2.3-fold) following recurrent prosulfocarb selection, to levels comparable to those observed in susceptible plants or when trifluralin metabolism was inhibited by treatment with the insecticide phorate. CONCLUSIONS: This study provides evidence that trait(s) enabling efficient trifluralin metabolism in L. rigidum are purged from the population under prosulfocarb recurrent selection. The level of trifluralin metabolism in vitro and its inhibition caused by phorate action on trifluralin-metabolizing enzyme(s) is equivalent to the effect produced by prosulfocarb selection. The hypothetical link between the two phenomena is that the putative monooxygenase(s) conferring trifluralin metabolic resistance also mediate the activation of prosulfocarb to its toxic sulfoxide. Thus, we speculate that survival to prosulfocarb via a lack of metabolic herbicide activation, and survival to trifluralin conferred by enhanced herbicide metabolism, are mutually exclusive. These findings not only open up a new research direction in terms of the interaction between different herbicide resistance mechanisms in L. rigidum, but also offer strategies for immediate management of the population dynamics of metabolism-based resistance in the field. © 2020 Society of Chemical Industry.

Biodegradable poly(3-hydroxybutyrate-co-4-hydroxybutyrate) microcapsules for controlled release of trifluralin with improved photostability and herbicidal activity.

Microencapsulation of pesticide is a promising technology to reduce the negative environmental impact and benefit the sustainable development. Trifluralin, commonly used as a selective pre-emergence herbicide, is vulnerably subject to loss by volatilization and decomposition by sunlight when applied to the surface of soils. In the present study, trifluralin has been encapsulated using biodegradable poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (PHB) polymers as carriers to develop controlled release formulations. PHB trifluralin microcapsules were obtained using a convenient solvent evaporation method. The influences of preparation parameters on the size and its distribution of the microcapsules were discussed. The particle size decreased from 4.44 µm to 2.50 µm as the shearing speeds increased from 4000 r/min to 12,000 r/min, and the value decreased from 3.64 µm to 3.23 µm as the mass fraction of emulsifier polyvinyl alcohol increased from 0.5% to 2.0%. The loading content (LC) as well as the encapsulation efficiency (EE) of trifluralin microcapsules are multiple factors dependent. Orthogonal table L9(34) was designed and range analysis was used to suggest the optimal preparation parameters. When performed under the optimized conditions, the corresponding LC and EE were 16.50% and 90.65%, respectively. The release of trifluralin from PHB microcapsules showed slow and sustained patterns, which could be easily achieved by modifying the preparation parameters including shearing speed and concentration of emulsifier. Compared to conventional trifluralin formulation of emulsifiable concentrate, trifluralin microcapsules exhibited significantly improved photostability and herbicidal activity against target weed barnyardgrass. These results demonstrated that microencapsulation with PHB could dramaticlly improve the effective utilization rate and decrease the dosage of such agricultural chemicals.

Enhanced Trifluralin Metabolism Can Confer Resistance in Lolium rigidum.

Resistance to the pre-emergence herbicide trifluralin is increasing in Australian annual ryegrass ( Lolium rigidum) populations. Three L. rigidum populations (R1, R2, and R3) collected from Australian grain fields were identified with trifluralin resistance. Both target-site and nontarget-site resistance mechanisms were investigated. No target-site α-tubulin mutations were detected in populations R1 and R3, while an Arg-243-Lys mutation was found in R2. Compared with the three trifluralin-susceptible populations, enhanced [14C]-trifluralin metabolism, quantified by measuring the amount of [14C] label partitioning into the polar phase of a hexane:methanol system, was identified in all the three resistant populations. This is the first report of metabolic resistance to trifluralin. Coevolution of target-site and nontarget-site resistance to trifluralin is occurring, and metabolic resistance is not rare in L. rigidum populations in Australia. A method was established for trifluralin metabolic resistance detection, overcoming the difficulties of quantifying this highly volatile herbicide by chromatographic methods.

Fifty years of herbicide research: comparing the discovery of trifluralin and halauxifen-methyl.

Fifty years separate the commercialization of the herbicides trifluralin and halauxifen-methyl. Despite the vast degree of technological change that occurred over that time frame, some aspects of their discovery stories are remarkably similar. For example, both herbicides were prepared very early in the iterative discovery process and both were developed from known lead compound structures by hypothesis-driven research efforts without the use of in vitro assays or computer-aided molecular design. However, there are aspects of the halauxifen-methyl and trifluralin discovery stories that are substantially different. For example, the chemical technology required for the cost-effective production of halauxifen-methyl simply did not exist just two decades prior to its commercial launch. By contrast, the chemical technology required for the cost-effective production of trifluralin was reported in the chemical literature more than two decades prior to its commercial launch. In addition, changes in regulatory environment since the early 1960s ensured that their respective discovery to commercial launch stories would also differ in substantial ways. Ultimately, the time and cost required to develop and register halauxifen-methyl demanded a global initial business case while the lower registration hurdles that trifluralin cleared enabled a narrow initial business case mainly focused on the USA. © 2017 Society of Chemical Industry.

Dinitroaniline herbicide resistance in a multiple-resistant Lolium rigidum population.

BACKGROUND: The pre-emergence dinitroaniline herbicides (such as trifluralin and pendimethalin) are vital to Australian no-till farming systems. A Lolium rigidum population collected from the Western Australian grain belt with a 12-year trifluralin use history was characterised for resistance to dinitroaniline, acetyl CoA carboxylase (ACCase)- and acetolactate synthase (ALS)-inhibiting herbicides. Target-site resistance mechanisms were investigated. RESULTS: This L. rigidum population exhibited 32-fold resistance to trifluralin, as compared with the susceptible population. It also displayed 12- to 30-fold cross-resistance to other dinitroaniline herbicides (pendimethalin, ethalfluralin and oryzalin). In addition, this population showed multiple resistance to commonly used post-emergence ACCase- and ALS-inhibiting herbicides. Two target-site α-tubulin gene mutations (Val-202-Phe and Thr-239-Ile) previously documented in other dinitroaniline-resistant weed species were identified, and some known target-site mutations in ACCase (Ile-1781-Leu, Asp-2078-Gly and Cys-2088-Arg) and ALS (Pro-197-Gln/Ser) were found in the same population. An agar-based Petri dish screening method was established for the rapid diagnosis of resistance to dinitroaniline herbicides. CONCLUSION: Evolution of target-site resistance to both pre- and post-emergence herbicides was confirmed in a single L. rigidum population. The α-tubulin mutations Val-202-Phe and Thr-239-Ile, documented here for the first time in L. rigidum, are likely to be responsible for dinitroaniline resistance in this population. Early detection of dinitroaniline herbicide resistance and integrated weed management strategies are needed to maintain the effectiveness of dinitroaniline herbicides. © 2017 Society of Chemical Industry.

An automated quantitative image analysis tool for the identification of microtubule patterns in plants.

High throughput confocal imaging poses challenges in the computational image analysis of complex subcellular structures such as the microtubule cytoskeleton. Here, we developed CellArchitect, an automated image analysis tool that quantifies changes to subcellular patterns illustrated by microtubule markers in plants. We screened microtubule-targeted herbicides and demonstrate that high throughput confocal imaging with integrated image analysis by CellArchitect can distinguish effects induced by the known herbicides indaziflam and trifluralin. The same platform was used to examine 6 other compounds with herbicidal activity, and at least 3 different effects induced by these compounds were profiled. We further show that CellArchitect can detect subcellular patterns tagged by actin and endoplasmic reticulum markers. Thus, the platform developed here can be used to automate image analysis of complex subcellular patterns for purposes such as herbicide discovery and mode of action characterisation. The capacity to use this tool to quantitatively characterize cellular responses lends itself to application across many areas of biology.

Inhibition of the in vitro growth of Babesia bigemina, Babesia caballi and Theileria equi parasites by trifluralin analogues.

Bovine and equine babesiosis caused by Babesia bovis, Babesia bigemina and Babesia caballi, along with equine theileriosis caused by Theileria equi are global tick-borne hemoprotozoan diseases characterized by fever, anemia, weight losses and abortions. A common feature of these diseases are transition from acute to chronic phases, in which parasites may persist in the hosts for life. Antiprotozoal drugs are important for managing infection and disease. Previous research demonstrated that trifluralin analogues, designated (TFLAs) 1-15, which specifically bind to regions of alpha-tubulin protein in plants and protozoan parasites, have the ability to inhibit the in vitro growth of B. bovis. The inhibitory activity of TFLAs 1-15 minus TFLA 5 was tested in vitro against cultured B. bigemina, B. caballi and T. equi. The four TFLAs with greatest inhibitory activity were then analyzed for hemolytic activity and toxicity against erythrocytes. All TFLAs tested in the study showed inhibitory effects against the three parasite species. TFLA 2, TFLA 11, TFLA 13 and TFLA 14 were the most effective inhibitors for the three species tested, with estimated IC50 between 5.1 and 10.1µM at 72h. The drug's solvent (DMSO/ethanol) did not statistically affect the growth of the parasites nor cause hemolysis. Also, TFLA 2, 13 and 14 did not cause statistically significant hemolytic activity on bovine and equine erythrocytes at 15µM, and TFLA 2, 11 and 13 had no detectable toxic effects on bovine and equine erythrocytes at 15µM, suggesting that these drugs do not compromise erythrocyte viability. The demonstrated ability of the trifluralin analogues to inhibit in vitro growth of Babesia spp. and Theileria equi, and their lack of toxic effects on erythrocytes supports further in vivo testing and eventually their development as novel alternatives for the treatment of babesiosis and theileriosis.

Herbicide oryzalin inhibits human carbonic anhydrases in vitro.

Herbicides of the dinitroaniline chemical class, widely used oryzalin and trifluralin, and also nitralin were tested as inhibitors of recombinant human carbonic anhydrases (CAs). Oryzalin bound and inhibited 11 out of 12 catalytically active CA isoforms present in the human body with the affinities in the same range as clinically used CA drugs, while no effect was detected for the other two compounds. Binding of all three herbicides was examined by fluorescence-based thermal shift assay, isothermal titration calorimetry, and the inhibition of carbon dioxide hydratase activity. During the last decade, dinitroaniline compound-based therapies against protozoan diseases are being developed. Therefore, it is important to investigate their potential off-target effects, including human CAs.

Anthelmintic effect of herbicidal dinitroanilines on the nematode model Caenorhabditis elegans.

Dinitroanilines are known herbicides that impair the polymerization of microtubules. This study investigated the effects of oryzalin and trifluralin on the viability, morphology, and ultrastructure of different life stages of Caenorhabditis elegans. Both drugs reduced the survival of the adult population in 50% after three days of treatment with concentrations of approximately 30 µM and 57 µM, respectively. The development of new adults was monitored for seven days and treatment with both drugs also showed a decrease in the adult population. 25 µM Oryzalin or trifluralin inhibited the hatching of eggs by nearly 100%. Both drugs showed remarkable larvicidal activity at 25 µM against the larvae at first and second stages (L1-L2) and at third and fourth stages (L3-L4) after 24 h. Treatment with dinitroanilines led to incomplete egg embryo development. The oryzalin and trifluralin treatments caused the detachment of cuticular layers of adults and larvae and the formation of a large number of intracellular membrane whirls and lipid bodies in the hypodermal cells and non-contractile muscles of adults. Both drugs also provoked the bagging process, which generated lesions in the uterus of the adults. In addition, trifluralin caused the detachment of certain areas of the cuticle adjacent to the hypodermis in a large number of nematodes. Our results suggest that dinitroanilines are a potentially new alternative for anthelmintic chemotherapy.

[Obtaining the transgenic lines of finger millet Eleusine coracana (L.) Gaertn. With dinitroaniline resistance].

The current data is dedicated to the study of bioballistic and Agrobacterium-mediated transformation of finger millet with the constructs carrying the mutant alpha-tubulin gene (TUAm 1), isolated from R-biotype goosegrass (Eleusine indica L.), for the decision of problem of dinitroaniline-resistance. It was found that 10 microM of trifluralin is optimal for the selection of transgene plants of finger millet. PCR analysis of transformed lines confirmed the transgene nature of plants. The analysis of seed of T1 oftransgene lines confirmed heterozygous character of inheritance of the resistance.

Exploitation of induced 2n-gametes for plant breeding.

Unreduced gamete formation derived via abnormal meiotic cell division is an important approach to polyploidy breeding. This process is considered the main driving force in spontaneous polyploids formation in nature, but the potential application of these gametes to plant breeding has not been fully exploited. An effective mechanism for their artificial induction is needed to attain greater genetic variation and enable efficient use of unreduced gametes in breeding programs. Different approaches have been employed for 2n-pollen production including interspecific hybridization, manipulation of environmental factors and treatment with nitrous oxide, trifluralin, colchicine, oryzalin and other chemicals. These chemicals can act as a stimulus to produce viable 2n pollen; however, their exact mode of action, optimum concentration and developmental stages are still not known. Identification of efficient methods of inducing 2n-gamete formation will help increase pollen germination of sterile interspecific hybrids for inter-genomic recombination and introgression breeding to develop new polyploid cultivars and increase heterozygosity among plant populations. Additionally, the application of genomic tools and identification and isolation of genes and mechanisms involved in the induction of 2n-gamete will enable increased exploitation in different plant species, which will open new avenues for plant breeding.

A novel alkyl phosphocholine-dinitroaniline hybrid molecule exhibits biological activity in vitro against Leishmania amazonensis.

Parasitic protozoa of the Leishmania genus cause leishmaniasis, an important complex of tropical diseases that affect about 12 million people around the world. The drugs used to treat leishmaniasis are pentavalent antimonials, miltefosine, amphotericin B and pentamidine. In the present study, we evaluated the effect of a novel alkyl phosphocholine-dinitroaniline hybrid molecule, TC95, against Leishmania amazonensis promastigotes and intracellular amastigotes. Antiproliferative assays indicated that TC95 is a potent inhibitor of promastigotes and intracellular amastigotes with IC50 values of 2.6 and 1.2 µM, respectively. Fluorescence microscopy with anti-α-tubulin antibody revealed changes in the cytoskeleton, whilst scanning electron microscopy showed alterations in the shape, plasma membrane, length of the flagellum, and cell cycle. Flow cytometry confirmed the cell cycle arrest mainly in G1 phase, however a significant population appeared in sub G0/G1 and super-G2. The alterations in the plasma membrane integrity were confirmed by fluorometric analysis using Sytox Blue. Transmission electron microscopy also revealed an accumulation of lipid bodies, confirmed by fluorescence microscopy and fluorometric analysis using Nile Red. Important lesions were also observed in organelles such as mitochondrion, endoplasmic reticulum and Golgi complex. In summary, our study suggests that TC95, an alkyl phosphocholine-trifluralin hybrid molecule, is a promising novel compound against L. amazonensis.

Combination and monotherapy of Leishmania major infection in BALB/c mice using plant extracts and herbicides.

BACKGROUND & OBJECTIVES: Leishmaniasis is a growing health problem in many parts of the world. Efforts to find new chemotherapeutics for leishmaniasis remain a priority. This study was carried out to determine the effect of combination and monotherapies using plant extracts and herbicides on Leishmania major infection in BALB/c mice. METHODS: The herbicides and saponin extract were purchased from Sigma. Roots of Plumbago capensis were collected from Karura forest, Nairobi, Kenya. Plant extractions were done in KEMRI at Center for Traditional Medicines and Drugs Research. RESULTS: Lesion sizes after infection of BALB/c mice were similar in all the experimental groups till the onset of therapeutic treatments (p >0.05). At 15 days post-treatment, significant differences (p < 0.05) were discerned in the lesion sizes of the BALB/c mice in all the mono- and combined-treated groups. However, the combined therapies caused total elimination of the parasites from the lesions and significantly reduced parasite burden in liver and spleen compared to the untreated controls at the end of the experiment. INTERPRETATION & CONCLUSION: The results of this study demonstrate that combination therapy using alternative administration of saponin, acriflavine, trifluralin and plumbagin is effective in treating L. major infection in mice. In this regard, an investigation into the efficacy of these combined therapies against other Leishmania strains should be explored further. Furthermore, studies with these combination therapies should be done on non-human primates such as the vervet monkey (Cercopithecus aethiops).

In vitro induction of tetraploid garlic with trifluralin.

Garlic (Allium sativum) is propagated asexually. Since sexual cross breeding is almost impossible, means for effective breeding are not currently available and the available production cultivars are seriously aged and degenerated. A possible alternative for breeding is chemical induction. Trifluralin, a type of herbicide, has been reported to provoke chromosome doubling. However, this chemical had not been tested on garlic. We tested various trifluralin concentrations and treatment durations for efficiency in the induction of tetraploid garlic. A clove base of garlic with a stem cv. Gailiang was used as the ex-plant to induce calluses on Murashige and Skoog (MS) medium; the calluses were then inoculated onto MS medium containing different levels of trifluralin and cultured to induce chromosome number variation in vitro. Garlic calluses were effectively induced via the ex-plant and both shoots and roots differentiated well on MS medium containing 6-benzylaminopurine at 3.0 mg/L and indole-3-acetic acid at 0.1 mg/L. However, increases in trifluralin concentration and treatment duration reduced the survival rate and differentiation rate of calluses. Garlic callus cultured for 15 days on medium containing 100 µM trifluralin gave the highest rate of chromosome doubling. Through observation of chromosome number in the root apical cells and the morphology of guard cells on the leaf epidermis of the regenerated plantlets, it was clear that chromosome number variation was induced and tetraploids were produced in vitro by trifluralin treatment.

Mutation of alpha-tubulin genes in trifluralin-resistant water foxtail (Alopecurus aequalis).

BACKGROUND: Trifluralin-resistant biotypes of water foxtail (Alopecurus aequalis) have been identified in wheat fields from northern Kyushu, Japan. Water foxtail is a winter-annual grassy weed, causing substantial crop losses. This study reports on mutation in α-tubulin (TUA) genes from water foxtail, the site of action of trifluralin. RESULTS: Two trifluralin-sensitive (S) Chikugo and Ukiha biotypes and four trifluralin-resistant (R) Asakura-1, Asakura-2, Tamana and Tosu biotypes of water foxtail were used for herbicide resistance analysis. R biotypes showed 5.7-30.7-fold trifluralin resistance compared with the S biotypes. No differences in the uptake and translocation of (14)C-trifluralin were observed between Chikugo (S) biotype and Asakura-1 (R) biotype. Most of the (14)C detected in the plant material was in the root tissue, and no substantial increases were noted in shoot tissues. Comparative TUA sequence analysis revealed two independent single amino acid changes: change of Val into Phe at position 202 in TUA1 and change of Leu into Met at position 125 in TUA3 in Asakura-1 biotype. In the Tamana (R) biotype, two amino acid changes of Leu to Phe at position 136 and Val to Phe at position 202 were observed in the predicted amino acid sequence of TUA1, compared with Chikugo (S) biotype. CONCLUSION: The results provide preliminary molecular explanation for the resistance of water foxtail to trifluralin, a phenomenon that has arisen as a result of repeated exposure to this class of herbicide. This is the first report of α-tubulin mutation in water foxtail and for any Alopecurus species reported in the literature.

[Developing transgenic barley lines producing human lactoferrin using mutant alfa-tubulin gene as selective marker gene].

Method of biolistic transformation was used for genetic improvement of commercial barley cultivars (Oksamitoviy, Vodogray and Getman). The plasmid pHLFTuBA was used for particle bombardment that consists of the hLF gene under the control of the barley glutelin B-1 promoter and a selectable marker gene, alpha-tubulin conferring resistance to trifluralin (dinitroanilinr herbicide). Preliminary screening of different trifluralin concentration range from 0,1 to 30 microM was tested for determination of effective selective agent concentration. Two transgenic barley line of genotype Oksamitiviy and transgenic callus line of cultivar Getman were obtained after selection on 10 microM of trifluralin. To confirm the transgenic nature of regenerated plants, the PCR analysis was carried out. The 734bp length fragment of hLFgene was amplified from both regenerated plants.