RESUMO
Striga hermonthica (Sh) and S. asiatica (Sa) are major parasitic weeds limiting cereal crop production and productivity in sub-Saharan Africa (SSA). Under severe infestation, Striga causes yield losses of up to 100%. Breeding for Striga-resistant maize varieties is the most effective and economical approach to controlling the parasite. Well-characterized and genetically differentiated maize germplasm is vital to developing inbred lines, hybrids, and synthetic varieties with Striga resistance and desirable product profiles. The objective of this study was to determine the genetic diversity of 130 tropical and sub-tropical maize inbred lines, hybrids, and open-pollinated varieties germplasm using phenotypic traits and single nucleotide polymorphism (SNP) markers to select Striga-resistant and complementary genotypes for breeding. The test genotypes were phenotyped with Sh and Sa infestations using a 13x10 alpha lattice design with two replications. Agro-morphological traits and Striga-resistance damage parameters were recorded under a controlled environment. Further, high-density Diversity Array Technology Sequencing-derived SNP markers were used to profile the test genotypes. Significant phenotypic differences (P<0.001) were detected among the assessed genotypes for the assessed traits. The SNP markers revealed mean gene diversity and polymorphic information content of 0.34 and 0.44, respectively, supporting the phenotypic variation of the test genotypes. Higher significant variation was recorded within populations (85%) than between populations using the analysis of molecular variance. The Structure analysis allocated the test genotypes into eight major clusters (K = 8) in concordance with the principal coordinate analysis (PCoA). The following genetically distant inbred lines were selected, displaying good agronomic performance and Sa and Sh resistance: CML540, TZISTR25, TZISTR1248, CLHP0303, TZISTR1174, TZSTRI113, TZDEEI50, TZSTRI115, CML539, TZISTR1015, CZL99017, CML451, CML566, CLHP0343 and CML440. Genetically diverse and complementary lines were selected among the tropical and sub-tropical maize populations that will facilitate the breeding of maize varieties with Striga resistance and market-preferred traits.
Assuntos
Polimorfismo de Nucleotídeo Único , Striga , Zea mays , Zea mays/genética , Zea mays/parasitologia , Striga/fisiologia , Striga/genética , Variação Genética , Fenótipo , Genótipo , Doenças das Plantas/parasitologia , Doenças das Plantas/genética , Resistência à Doença/genética , Melhoramento Vegetal , Plantas Daninhas/genética , Clima Tropical , Marcadores GenéticosRESUMO
The yield of pearl millet, a resilient cereal crop crucial for African food security, is severely impacted by the root parasitic weed Striga hermonthica, which requires host-released hormones, called strigolactones (SLs), for seed germination. Herein, we identify four SLs present in the Striga-susceptible line SOSAT-C88-P10 (P10) but absent in the resistant 29Aw (Aw). We generate chromosome-scale genome assemblies, including four gapless chromosomes for each line. The Striga-resistant Aw lacks a 0.7 Mb genome segment containing two putative CARLACTONOIC ACID METHYLTRANSFERASE1 (CLAMT1) genes, which may contribute to SL biosynthesis. Functional assays show that P10CLAMT1b produces the SL-biosynthesis intermediate methyl carlactonoate (MeCLA) and that MeCLA is the precursor of P10-specific SLs. Screening a diverse pearl millet panel confirms the pivotal role of the CLAMT1 section for SL diversity and Striga susceptibility. Our results reveal a reason for Striga susceptibility in pearl millet and pave the way for generating resistant lines through marker-assisted breeding or direct genetic modification.
Assuntos
Genoma de Planta , Lactonas , Pennisetum , Striga , Striga/genética , Lactonas/metabolismo , Pennisetum/genética , Pennisetum/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Cromossomos de Plantas/genética , Doenças das Plantas/parasitologia , Doenças das Plantas/genética , Metiltransferases/metabolismo , Metiltransferases/genética , Plantas Daninhas/genética , Plantas Daninhas/metabolismo , Resistência à Doença/genética , Reguladores de Crescimento de Plantas/metabolismoRESUMO
Amaranthus retroflexus L. (redroot pigweed) is one of the most problematic weeds in maize, sugar beet, vegetables, and soybean crop fields in Europe. Two pigweed amaranth biotypes (R1 and R2) from the Czech Republic resistant to photosystem II (PSII)-inhibiting herbicides were analyzed in this study. This study aimed to identify the genetic mechanisms that underlie the resistance observed in the biotypes. Additionally, we also intended to establish the use of chlorophyll fluorescence measurement as a rapid and reliable method for confirming herbicide resistance in this weed species. Both biotypes analyzed showed high resistance factors in a dose-response study and were thus confirmed to be resistant to PSII-inhibiting herbicides. A sequence analysis of the D1 protein revealed a well-known Ser-Gly substitution at amino acid position 264 in both biotypes. Molecular docking studies, along with the wild-type and mutant D1 protein's secondary structure analyses, revealed that the S264G mutation did not reduce herbicide affinity but instead indirectly affected the interaction between the target protein and the herbicides. The current study identified the S264G mutation as being responsible for conferring herbicide resistance in the pigweed amaranth biotypes. These findings can provide a strong basis for future studies that might use protein structure and mutation-based approaches to gain further insights into the detailed mechanisms of resistance in this weed species. In many individuals from both biotypes, resistance at a very early stage (BBCH10) of plants was demonstrated several hours after the application of the active ingredients by the chlorophyll fluorescence method. The effective PS II quantum yield parameter can be used as a rapid diagnostic tool for distinguishing between sensitive and resistant plants on an individual level. This method can be useful for identifying herbicide-resistant weed biotypes in the field, which can help farmers and weed management practitioners develop more effective weed control tactics.
Assuntos
Amaranthus , Resistência a Herbicidas , Herbicidas , Complexo de Proteína do Fotossistema II , Amaranthus/genética , Amaranthus/efeitos dos fármacos , Amaranthus/crescimento & desenvolvimento , Resistência a Herbicidas/genética , Herbicidas/farmacologia , República Tcheca , Complexo de Proteína do Fotossistema II/genética , Complexo de Proteína do Fotossistema II/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Daninhas/genética , Plantas Daninhas/efeitos dos fármacos , Simulação de Acoplamento Molecular , MutaçãoRESUMO
Despite major breeding efforts by various national and international agencies, yields for the ~40 million hectares of maize, the major food crop in sub-Saharan Africa, have stagnated at <2 tons/ha/year for the past decade, one-third the global average. Breeders have succeeded in breeding increased yield with a modicum of tolerance to some single-weed or pathogen stresses. There has been minimal adoption of these varieties because introgressing polygenic yield and tolerance traits into locally adapted material is very challenging. Multiple traits to deal with pests (weeds, pathogens, and insects) are needed for farmer acceptance, because African fields typically encounter multiple pest constraints. Also, maize has no inherent resistance to some of these pest constraints, rendering them intractable to traditional breeding. The proposed solution is to simultaneously engineer multiple traits into one genetic locus. The dominantly inherited multi-pest resistance trait single locus can be bred simply into locally adapted, elite high-yielding material, and would be valuable for farmers, vastly increasing maize yields, and allowing for more than regional maize sufficiency. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Assuntos
Plantas Geneticamente Modificadas , Zea mays , Zea mays/genética , Plantas Geneticamente Modificadas/genética , África Subsaariana , Animais , Doenças das Plantas/parasitologia , Insetos/genética , Insetos/fisiologia , Plantas Daninhas/genética , Controle de Plantas Daninhas/métodos , Produtos Agrícolas/genéticaRESUMO
First synthetic "gene drive" for plants could help tame weeds-or transform them.
Assuntos
Tecnologia de Impulso Genético , Genes Sintéticos , Plantas Daninhas , Transformação Genética , Controle de Plantas Daninhas , Tecnologia de Impulso Genético/métodos , Genes de Plantas , Plantas Daninhas/genética , Plantas Geneticamente Modificadas , Controle de Plantas Daninhas/métodosRESUMO
Weeds present a significant challenge to agricultural productivity, and acetyl-CoA carboxylase (ACCase)-inhibiting herbicides have proven to be effective in managing weed populations in rice fields. To develop ACCase-inhibiting herbicide-resistant rice, we generated mutants of rice ACCase (OsACC) featuring Ile-1792-Leu or Gly-2107-Ser substitutions through ethyl methyl sulfonate (EMS) mutagenesis. The Ile-1792-Leu mutant displayed cross-resistance to aryloxyphenoxypropionate (APP) and phenylpyrazoline (DEN) herbicides, whereas the Gly-2107-Ser mutants primarily exhibited cross-resistance to APP herbicides with diminished resistance to the DEN herbicide. In vitro assays of the OsACC activity revealed an increase in resistance to haloxyfop and quizalofop, ranging from 4.84- to 29-fold in the mutants compared to that in wild-type. Structural modeling revealed that both mutations likely reduce the binding affinity between OsACC and ACCase inhibitors, thereby imparting resistance. This study offers insights into two target-site mutations, contributing to the breeding of herbicide-resistant rice and presenting alternative weed management strategies in rice cultivation.
Assuntos
Acetil-CoA Carboxilase , Inibidores Enzimáticos , Resistência a Herbicidas , Herbicidas , Mutação , Oryza , Proteínas de Plantas , Acetil-CoA Carboxilase/genética , Acetil-CoA Carboxilase/antagonistas & inibidores , Acetil-CoA Carboxilase/metabolismo , Acetil-CoA Carboxilase/química , Oryza/genética , Oryza/enzimologia , Herbicidas/farmacologia , Herbicidas/química , Resistência a Herbicidas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/genética , Plantas Daninhas/enzimologiaRESUMO
Phytoene desaturase (PDS) is a critical functional enzyme in blocking ζ-carotene biosynthesis and is one of the bleaching herbicide targets. At present, norflurazon (NRF) is the only commercial pyridazine herbicide targeting PDS. Therefore, developing new and diverse pyridazine herbicides targeting PDS is urgently required. In this study, diflufenican (BF) was used as the lead compound, and a scaffold-hopping strategy was employed to design and synthesize some pyridazine derivatives based on the action mode of BF and PDS. The preemergence herbicidal activity tests revealed that compound 6-chloro-N-(2,4-difluorophenyl)-3-(3-(trifluoromethyl)phenoxy)pyridazine-4-carboxamide (B1) with 2,4-diF substitution in the benzeneamino ring showed 100% inhibition rates against the roots and stems of Echinochloa crus-galli and Portulaca oleracea at 100 µg/mL, superior to the inhibition rates of BF. Meanwhile, compound B1 demonstrated excellent postemergence herbicidal activity against broadleaf weeds, which was similar to that of BF (inhibition rate of 100%) but superior to that of NRF. This indicated that 6-Cl in the pyridazine ring is the key group for postemergence herbicidal activity. In addition, compound B1 could induce downregulation of PDS gene expression, 15-cis-phytoene accumulation, and Y(II) deficiency and prevent photosynthesis. Therefore, B1 can be considered as a promising candidate for developing high-efficiency PDS inhibitors.
Assuntos
Echinochloa , Herbicidas , Oxirredutases , Proteínas de Plantas , Plantas Daninhas , Piridazinas , Herbicidas/farmacologia , Herbicidas/química , Piridazinas/farmacologia , Piridazinas/química , Echinochloa/efeitos dos fármacos , Echinochloa/enzimologia , Echinochloa/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/antagonistas & inibidores , Oxirredutases/genética , Oxirredutases/metabolismo , Oxirredutases/antagonistas & inibidores , Oxirredutases/química , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/enzimologia , Plantas Daninhas/genética , Relação Estrutura-Atividade , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Raízes de Plantas/química , Raízes de Plantas/efeitos dos fármacos , Estrutura MolecularRESUMO
This study investigated the multiple herbicide resistance (MHR) mechanism of one Echinochloa crus-galli population that was resistant to florpyrauxifen-benzyl (FPB), cyhalofop-butyl (CHB), and penoxsulam (PEX). This population carried an Ala-122-Asn mutation in the acetolactate synthase (ALS) gene but no mutation in acetyl-CoA carboxylase (ACCase) and transport inhibitor response1 (TIR1) genes. The metabolism rate of PEX was 2-fold higher, and the production of florpyrauxifen-acid and cyhalofop-acid was lower in the resistant population. Malathion and 4-chloro-7-nitrobenzoxadiazole (NBD-Cl) could reverse the resistance, suggesting that cytochrome P450 (CYP450) and glutathione S-transferase (GST) contribute to the enhanced metabolism. According to RNA-seq and qRT-PCR validation, two CYP450 genes (CYP71C42 and CYP71D55), one GST gene (GSTT2), two glycosyltransferase genes (rhamnosyltransferase 1 and IAAGLU), and two ABC transporter genes (ABCG1 and ABCG25) were induced by CHB, FPB, and PEX in the resistant population. This study revealed that the target mutant and enhanced metabolism were involved in the MHR mechanism in E. crus-galli.
Assuntos
Sistema Enzimático do Citocromo P-450 , Echinochloa , Resistência a Herbicidas , Herbicidas , Mutação , Proteínas de Plantas , Resistência a Herbicidas/genética , Herbicidas/farmacologia , Herbicidas/metabolismo , Echinochloa/genética , Echinochloa/efeitos dos fármacos , Echinochloa/metabolismo , Echinochloa/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Acetil-CoA Carboxilase/genética , Acetil-CoA Carboxilase/metabolismo , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/genética , Plantas Daninhas/metabolismo , Acetolactato Sintase/genética , Acetolactato Sintase/metabolismo , Butanos , Nitrilas , Sulfonamidas , Uridina/análogos & derivadosRESUMO
Alternanthera sessilis is considered the closest relative to the invasive weed Alternanthera philoxeroides in China, making it an important native species for studying the invasive mechanisms and adaptations of A. philoxeroides. Chloroplasts play a crucial role in a plant's environmental adaptation, with their genomes being pivotal in the evolution and adaptation of both invasive and related species. However, the chloroplast genome of A. sessilis has remained unknown until now. In this study, we sequenced and assembled the complete chloroplast genome of A. sessilis using high-throughput sequencing. The A. sessilis chloroplast genome is 151,935 base pairs long, comprising two inverted repeat regions, a large single copy region, and a small single copy region. This chloroplast genome contains 128 genes, including 8 rRNA-coding genes, 37 tRNA-coding genes, 4 pseudogenes, and 83 protein-coding genes. When compared to the chloroplast genome of the invasive weed A. philoxeroides and other Amaranthaceae species, we observed significant variations in the ccsA, ycf1, and ycf2 regions in the A. sessilis chloroplast genome. Moreover, two genes, ccsA and accD, were found to be undergoing rapid evolution due to positive selection pressure. The phylogenetic trees were constructed for the Amaranthaceae family, estimating the time of independent species formation between A. philoxeroides and A. sessilis to be approximately 3.5186-8.8242 million years ago. These findings provide a foundation for understanding the population variation within invasive species among the Alternanthera genus.
Assuntos
Amaranthaceae , Genoma de Cloroplastos , Espécies Introduzidas , Filogenia , Genoma de Cloroplastos/genética , Amaranthaceae/genética , Plantas Daninhas/genética , Cloroplastos/genética , Sequenciamento de Nucleotídeos em Larga Escala , Evolução MolecularRESUMO
Weeds are attractive models for basic and applied research due to their impacts on agricultural systems and capacity to swiftly adapt in response to anthropogenic selection pressures. Currently, a lack of genomic information precludes research to elucidate the genetic basis of rapid adaptation for important traits like herbicide resistance and stress tolerance and the effect of evolutionary mechanisms on wild populations. The International Weed Genomics Consortium is a collaborative group of scientists focused on developing genomic resources to impact research into sustainable, effective weed control methods and to provide insights about stress tolerance and adaptation to assist crop breeding.
Assuntos
Genômica , Plantas Daninhas , Plantas Daninhas/genética , Genômica/métodos , Controle de Plantas Daninhas/métodos , Genoma de Planta , Produtos Agrícolas/genética , Resistência a Herbicidas/genética , Melhoramento Vegetal/métodosRESUMO
Alopecurus aequalis Sobol. is a predominant grass weed in Chinese winter wheat fields, posing a substantial threat to crop production owing to its escalating herbicide resistance. This study documented the initial instance of an A. aequalis population (AHFT-3) manifesting resistance to multiple herbicides targeting four distinct sites: acetyl-CoA carboxylase (ACCase), acetolactate synthase, photosystem II, and 1-deoxy-d-xylulose-5-phosphate synthase. AHFT-3 carried an Asp-to-Gly mutation at codon 2078 of ACCase, with no mutations in the remaining three herbicide target genes, and exhibited no overexpression of any target gene. Compared with the susceptible population AHFY-3, AHFT-3 metabolized mesosulfuron-methyl, isoproturon, and bixlozone faster. The inhibition and comparison of herbicide-detoxifying enzyme activities indicated the participation of cytochrome P450s in the resistance to all four herbicides, with glutathione S-transferases specifically linked to mesosulfuron-methyl. Three CYP72As and a Tau class glutathione S-transferase, markedly upregulated in resistant plants, potentially played pivotal roles in the multiple-herbicide-resistance phenotype.
Assuntos
Acetil-CoA Carboxilase , Resistência a Herbicidas , Herbicidas , Proteínas de Plantas , Poaceae , Resistência a Herbicidas/genética , Herbicidas/farmacologia , Herbicidas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Acetil-CoA Carboxilase/genética , Acetil-CoA Carboxilase/metabolismo , Poaceae/genética , Poaceae/metabolismo , Poaceae/efeitos dos fármacos , Acetolactato Sintase/genética , Acetolactato Sintase/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Mutação , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/genética , Plantas Daninhas/metabolismoRESUMO
Weedy rice, a pervasive and troublesome weed found across the globe, has often evolved through fertilization of rice cultivars with little importance of crop-weed gene flow. In Argentina, weedy rice has been reported as an important constraint since the early 1970s, and, in the last few years, strains with herbicide-resistance are suspected to evolve. Despite their importance, the origin and genetic composition of Argentinian weedy rice as well its adaptation to agricultural environments has not been explored so far. To study this, we conducted genotyping-by-sequencing on samples of Argentinian weedy and cultivated rice and compared them with published data from weedy, cultivated and wild rice accessions distributed worldwide. In addition, we conducted a phenotypic characterization for weedy-related traits, a herbicide resistance screening and genotyped accessions for known mutations in the acetolactate synthase (ALS) gene, which confers herbicide resistance. Our results revealed large phenotypic variability in Argentinian weedy rice. Most strains were resistant to ALS-inhibiting herbicides with a high frequency of the ALS mutation (A122T) present in Argentinian rice cultivars. Argentinian cultivars belonged to the three major genetic groups of rice: japonica, indica and aus while weeds were mostly aus or aus-indica admixed, resembling weedy rice strains from the Southern Cone region. Phylogenetic analysis supports a single origin for aus-like South American weeds, likely as seed contaminants from the United States, and then admixture with local indica cultivars. Our findings demonstrate that crop to weed introgression can facilitate rapid adaptation to agriculture environments.
Assuntos
Acetolactato Sintase , Resistência a Herbicidas , Herbicidas , Oryza , Oryza/genética , Resistência a Herbicidas/genética , Argentina , Acetolactato Sintase/genética , Plantas Daninhas/genética , Fenótipo , Genótipo , Adaptação Fisiológica/genética , Produtos Agrícolas/genética , Fluxo Gênico , Agricultura , MutaçãoRESUMO
Ammannia auriculata Willd. is a noxious broadleaf weed, commonly infesting rice ecosystems across southern China. A putative resistant A. auriculata population (AHSC-5) was sampled from a rice field of Anhui Province, where bensulfuron-methyl (BM) was unable to control its occurrence. This study aimed to determine the sensitivities of the AHSC-5 population to common-use herbicides, and to investigate the underlying resistance mechanisms. The bioassays showed that the AHSC-5 population was 138.1-fold resistant to BM, compared with the susceptible population (JSGL-1). Pretreatment of malathion reduced the resistance index to 19.5. ALS sequencing revealed an Asp376Glu substitution in the AHSC-5 population, and in vitro ALS activity assays found that 50% activity inhibition (I50) of BM in AHSC-5 was 75.4 times higher than that of JSGL-1. Moreover, the AHSC-5 population displayed cross-resistance to pyrazosulfuron-ethyl (10.6-fold), bispyribacsodium (3.6-fold), and imazethapyr (2.2-fold), and was in the process of evolving multiple resistance to synthetic auxin herbicides fluroxypyr (2.3-fold) and florpyrauxifen-benzyl (3.1-fold). This study proved the BM resistance in A. auriculata caused by the Asp376Glu mutation and P450-regulated metabolism. This multi-resistant population can still be controlled by penoxsulam, MCPA, bentazone, and carfentrazone-ethyl, which aids in developing targeted and effective weed management strategies.
Assuntos
Acetolactato Sintase , Sistema Enzimático do Citocromo P-450 , Resistência a Herbicidas , Herbicidas , Acetolactato Sintase/genética , Acetolactato Sintase/antagonistas & inibidores , Herbicidas/farmacologia , Resistência a Herbicidas/genética , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Malation/farmacologia , Compostos de Sulfonilureia/farmacologia , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/genética , Substituição de AminoácidosRESUMO
Weeds are the primary biotic constraint affecting sesame growth and production. Here, we applied EMS mutagenesis to an elite sesame cultivar and discovered a novel point mutation in the sesame SiALS gene conferring resistance to imidazolinone, a group of acetolactate-synthase (ALS)-inhibitors. The mutant line exhibited high resistance to imazamox, an ALS-inhibitor, with hybrid plants displaying an intermediate response. Field-based validation confirmed the mutant line's substantial resistance, leading to a significantly higher yield under imazamox treatment. Under pre-emergence application of imazapic, the mutant plants sustained growth, whereas wild-type and weed were effectively controlled. Field trials using s-metolachlor and imazapic combined resulted in weed-free plots compared to untreated controls. Consequently, this treatment showed a significantly greater yield (2280 vs. 880 Kg ha-1) than the commercial practice (s-metolachlor). Overall, our study unveils the potential of utilizing this point mutation in sesame breeding programs, offering new opportunities for integrated weed management strategies for sesame cultivation. Developing herbicide-resistant crop plants holds promise for supporting sustainable production and addressing the challenges of weed infestations in sesame farming.
Assuntos
Resistência a Herbicidas , Herbicidas , Sesamum , Controle de Plantas Daninhas , Controle de Plantas Daninhas/métodos , Resistência a Herbicidas/genética , Sesamum/genética , Sesamum/crescimento & desenvolvimento , Herbicidas/farmacologia , Acetolactato Sintase/genética , Plantas Daninhas/genética , Plantas Daninhas/efeitos dos fármacos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Mutação , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimentoRESUMO
Transgenic, dicamba-resistant soybean and cotton were developed to enable farmers to combat weeds that had evolved resistance to the herbicide glyphosate. The dramatic increases in dicamba use these crops facilitated have led to serious problems, including the evolution of dicamba-resistant weeds and widespread damage to susceptible crops and farming communities. Disturbingly, this pattern of dicamba use has unfolded while the total herbicide applied to soybean has nearly doubled since 2006. Without substantive changes to agricultural policy and decision making, the next 'silver-bullet' agrotechnology will likely be no more than another step on the transgene-facilitated herbicide treadmill. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Assuntos
Glycine max , Glifosato , Resistência a Herbicidas , Herbicidas , Plantas Daninhas , Plantas Geneticamente Modificadas , Herbicidas/farmacologia , Resistência a Herbicidas/genética , Plantas Geneticamente Modificadas/genética , Glycine max/genética , Glycine max/efeitos dos fármacos , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/genética , Transgenes , Dicamba/farmacologia , Controle de Plantas Daninhas/métodos , Gossypium/genética , Glicina/análogos & derivados , Glicina/farmacologia , Produtos Agrícolas/genéticaRESUMO
BACKGROUND: Japanese brome (Bromus japonicus Thumb.) is one of the problematic annual weeds in winter wheat (Triticum aestivum L.) and is generally controlled by acetolactate synthase (ALS) inhibitors. Repeated use of the ALS inhibitor propoxycarbazone-Na resulted in the evolution of resistance to this herbicide in three B. japonicus populations, i.e., R1, R2, and R3 in Kansas (KS). However, the level of resistance and mechanism conferring resistance in these populations is unknown. The objectives of this research were to (i) evaluate the level of resistance to propoxycarbazone-Na in R1, R2, and R3 in comparison with a known susceptible population (S1), (ii) investigate the mechanism of resistance involved in conferring ALS-inhibitor resistance, and (iii) investigate the cross-resistance to other ALS inhibitors. RESULTS: Dose-response (0 to 16x; x = 44 g ai ha-1 of propoxycarbazone-Na) assay indicated 167, 125, and 667-fold resistance in R1, R2 and R3 populations, respectively, compared to S1 population. ALS gene sequencing confirmed the mutations resulting in amino acid substitutions, i.e., Pro-197-Thr (R3, R1)/Ser (R2, R1) bestowing resistance to these ALS inhibitors. Such amino acid substitutions also showed differential cross-resistance to sulfosulfuron, mesosulfuron-methyl, pyroxsulam, and imazamox among resistant populations. Pretreatment with malathion (a cytochrome P450 enzyme-inhibitor) followed by imazamox treatment suggested cross-resistance to this herbicide possibly via metabolism only in R3 population. CONCLUSION: Overall, these results confirm the first case of target-site based resistance to ALS inhibitors in B. japonicus in the US, highlighting the need for exploring herbicides with alternative modes of action to enhance weed control in winter wheat. © 2024 Society of Chemical Industry.
Assuntos
Acetolactato Sintase , Bromus , Resistência a Herbicidas , Herbicidas , Proteínas de Plantas , Acetolactato Sintase/genética , Acetolactato Sintase/antagonistas & inibidores , Acetolactato Sintase/metabolismo , Bromus/enzimologia , Bromus/efeitos dos fármacos , Bromus/genética , Resistência a Herbicidas/genética , Herbicidas/farmacologia , Kansas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/antagonistas & inibidores , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/genética , Plantas Daninhas/enzimologiaRESUMO
Parthenium hysterophorus, a globally widespread weed, poses a significant threat to agricultural ecosystems due to its invasive nature. We investigated the chloroplast genome of P. hysterophorus in this study. Our analysis revealed that the chloroplast genome of P. hysterophorus spans a length of 151,881 base pairs (bp). It exhibits typical quadripartite structure commonly found in chloroplast genomes, including inverted repeat regions (IR) of 25,085 bp, a small single copy (SSC) region of 18,052 bp, and a large single copy (LSC) region of 83,588 bp. A total of 129 unique genes were identified in P. hysterophorus chloroplast genomes, including 85 protein-coding genes, 36 tRNAs, and eight rRNAs genes. Comparative analysis of the P. hysterophorus plastome with those of related species from the tribe Heliantheae revealed both conserved structures and intriguing variations. While many structural elements were shared among the species, we identified a rearrangement in the large single-copy region of P. hysterophorus. Moreover, our study highlighted notable gene divergence in several specific genes, namely matK, ndhF, clpP, rps16, ndhA, rps3, and ndhD. Phylogenetic analysis based on the 72 shared genes placed P. hysterophorus in a distinct clade alongside another species, P. argentatum. Additionally, the estimated divergence time between the Parthenium genus and Helianthus (sunflowers) was approximately 15.1 million years ago (Mya). These findings provide valuable insights into the evolutionary history and genetic relationships of P. hysterophorus, shedding light on its divergence and adaptation over time.
Assuntos
Asteraceae , Genoma de Cloroplastos , Filogenia , Plantas Daninhas/genética , Parthenium hysterophorus , Ecossistema , Asteraceae/genéticaRESUMO
BACKGROUND: The early detection of herbicide resistance in weeds is a key factor to avoid herbicide waste and improve agriculture sustainability. The present study aimed to develop and validate an allele-specific loop-mediated isothermal amplification (AS-LAMP) assay for the quick on-site detection of the resistance-endowing point mutation Trp-574-Leu in the acetolactate synthase (ALS) gene in three widely diffused Amaranthus weed species: Amaranthus retroflexus, Amaranthus hybridus and Amaranthus tuberculatus. RESULTS: The AS-LAMP protocol was developed on wild-type and ALS-mutant plants of the three species and revealed that the amplification approach with only the primer set specific for the mutant allele (574-Leu) was the most promising. The validation and estimation of the AS-LAMP performance evaluated by comparing the results with those of the molecular marker (cleaved amplified polymorphic sequences) indicated that, although the sensitivity and specificity were relatively high in all species (overall 100 and > 65%, respectively), precision was high for A. hybridus L. and A. retroflexus L. (75 and 79%, respectively), but quite low for A. tuberculatus (Moq.) J. D. Sauer (59%). The LAMP assay was also effective on crude genomic DNA extraction, allowing the quick detection of mutant plants in field situation (on site resistance detection). CONCLUSION: The proposed AS-LAMP method has proven to be a promising technique for rapid detection of resistance as a result of Trp-574-Leu on the two monoecious weedy Amaranthus species but resulted less effective in the genetically variable dioecious species A. tuberculatus. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Assuntos
Acetolactato Sintase , Amaranthus , Resistência a Herbicidas , Herbicidas , Técnicas de Amplificação de Ácido Nucleico , Proteínas de Plantas , Plantas Daninhas , Amaranthus/genética , Amaranthus/efeitos dos fármacos , Acetolactato Sintase/genética , Acetolactato Sintase/metabolismo , Acetolactato Sintase/antagonistas & inibidores , Técnicas de Amplificação de Ácido Nucleico/métodos , Resistência a Herbicidas/genética , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Herbicidas/farmacologia , Inibidores Enzimáticos/farmacologia , Técnicas de Diagnóstico MolecularRESUMO
High reproductive compatibility between crops and their wild relatives can provide benefits for crop breeding but also poses risks for agricultural weed evolution. Weedy rice is a feral relative of rice that infests paddies and causes severe crop losses worldwide. In regions of tropical Asia where the wild progenitor of rice occurs, weedy rice could be influenced by hybridization with the wild species. Genomic analysis of this phenomenon has been very limited. Here we use whole genome sequence analyses of 217 wild, weedy and cultivated rice samples to show that wild rice hybridization has contributed substantially to the evolution of Southeast Asian weedy rice, with some strains acquiring weed-adaptive traits through introgression from the wild progenitor. Our study highlights how adaptive introgression from wild species can contribute to agricultural weed evolution, and it provides a case study of parallel evolution of weediness in independently-evolved strains of a weedy crop relative.
Assuntos
Variação Genética , Oryza , Evolução Molecular , Porosidade , Melhoramento Vegetal , Sudeste Asiático , Plantas Daninhas/genética , Oryza/genéticaRESUMO
Weeds pose a significant threat to crop production, resulting in substantial yield reduction. In addition, they possess robust weedy traits that enable them to survive in extreme environments and evade human control. In recent years, the application of multi-omics biotechnologies has helped to reveal the molecular mechanisms underlying these weedy traits. In this review, we systematically describe diverse applications of multi-omics platforms for characterizing key aspects of weed biology, including the origins of weed species, weed classification, and the underlying genetic and molecular bases of important weedy traits such as crop-weed interactions, adaptability to different environments, photoperiodic flowering responses, and herbicide resistance. In addition, we discuss limitations to the application of multi-omics techniques in weed science, particularly compared with their extensive use in model plants and crops. In this regard, we provide a forward-looking perspective on the future application of multi-omics technologies to weed science research. These powerful tools hold great promise for comprehensively and efficiently unraveling the intricate molecular genetic mechanisms that underlie weedy traits. The resulting advances will facilitate the development of sustainable and highly effective weed management strategies, promoting greener practices in agriculture.