Akram MUHAMMAD, Aftab FAHEEM＊Abstract In this presentation, we report on de novo and axillary shoot regeneration and rooting of shoots maintained over a long term, from cultures of Tectona grandis L. Shoot-tips of te...Akram MUHAMMAD, Aftab FAHEEM＊Abstract In this presentation, we report on de novo and axillary shoot regeneration and rooting of shoots maintained over a long term, from cultures of Tectona grandis L. Shoot-tips of teak shoots forced from epicormic buds were used as the starting material for axenie shoot-culture establishment. Long term maintenance of such axenic shoot cultures was carried out by regular sub-culturing on MS media supplemented with N6-benzyleadenine （BA, 8.8 μmol·L^-1） and indole-3-butyric acid （IBA, 2 μmol·L ^1） for 24 months. Vigorously growing shoot tips （2-3 cm long） were inoculated on the MS basal medium supplemented with different concentrations （0, 1, 2, 4, 6, 8 or 10 p.mol-L-~） of either [BA or a-naphthaleneacetic acid （NAA） for rooting. Axillary and de novo shoots were de- veloped from axillary and cut basal ends of shoots, respectively. Shoots growing on auxins were further sub-cultured （every 15 days） and maintained for 45 days. The greatest number of de novo （5.06） as well as axillary shoots （2.85） was observed on the MS medium supplemented with 10 μmol-L^-1 NAA or 8 μmol·L^-1 IBA, respectively, after 45 days. The combinations of both IBA （μmol·L^-1） ＋ NAA （μmol·L^-1） were tested at different concentrations （4 ＋ 4, 6 ＋ 6, 8 ＋ 8） supplemented to a half strength MS basal medium with 0.1% activated charcoal for rooting of decapitated and non-decapitated de novo and axillary shoots. Rooting from non-decapitated de novo shoots was highest （93.33%） with a mean number of roots of 4.61 on this medium, supplemented with 6 μmol·L^-1 IBA ＋ 6 gmol.L l NAA, after 36 days of initial culture. Individual auxin, however, was not effective for root induction. Rooted shoots were acclimatized in a green house and after four weeks plantlets were transferred to the field.展开更多
The present study reports an efficient protocol for in vitro propagation of Thymus vulgaris L., an aromatic and medicinal plant in Morocco. Initially, we performed in vitro multiplication of Thymus vulgaris explants e...The present study reports an efficient protocol for in vitro propagation of Thymus vulgaris L., an aromatic and medicinal plant in Morocco. Initially, we performed in vitro multiplication of Thymus vulgaris explants existing in the laboratory and obtained from micropropagation by shoot tip culture. Afterwards, we have evaluated the effect of six macronutrients. After that, seven cytokinins (Kin, BAP, 2iP, DPU, Adenine, Zeatine and TDZ) in three different concentrations (0.46, 0.93, 2.32 μM) have been evaluated to optimize cultures multiplication and elongation. Moreover, the effect of three auxins (IAA, IBA and NAA) at 0.57 μM, combined to 4 cytokinins (Kin, BAP, DPU and Ad.) at 0.46 μM, on shoot rooting has been studied. Thereby, MS medium has been proved the most favorable for plantlets growing. Also, we found that the addition of certain cytokinins, specifically 0.46 Kin, 0.46 and 0.93 BAP, 0.46 2iP, 0.46 DPU, 0.46 Ad. and 0.46 Zeat., ensures better multiplication and growth of vitroplants. In addition, multiplication and rooting of cultures were well optimized after addition 0.46 Kin + 0.57 IAA or NAA, 0.46 DPU + 0.57 IBA and 0.46 Ad. + 0.57 IBA combinations to the culture medium. Lastly, plantlets with roots were successfully acclimatized to ex-vitro conditions and these latter served as a source to establish in vitro culture again.展开更多
An efficient in vitro method for rapid vegetative propagation of Bienertia sinuspersici, one of four terrestrial species of family Chenopodiaceae capable of performing C4 photosynthesis within a single cell, was devel...An efficient in vitro method for rapid vegetative propagation of Bienertia sinuspersici, one of four terrestrial species of family Chenopodiaceae capable of performing C4 photosynthesis within a single cell, was developed. Cuttings of B. sinuspersici were used to examine the effects of Murashige and Skoog (MS) media strength and auxins on adventitious root formation. Half-strength MS medium was determined to be ideal for adventitious root formation in Bienertia cuttings. Although cuttings cultured in medium containing 5.0 mg/L α-naphthalene acetic acid (NAA) promoted the highest number of adventitious roots, cuttings cultured in medium supplemented with 1.0 mg/L indole-3-butyric acid (IBA) produced the longest adventitious roots and had the highest survival rate upon transplanting to soil. Histological analysis revealed variations in the root anatomy generated by the various auxins which may affect adventitious root formation and subsequent establishment of cuttings in soil. Overall, the established procedure provides a simple and cost-effective means for the rapid propagation of the single-cell C4 species B. sinuspersici.展开更多
The effects of auxins and media on callus induction from the mature and immature embryos of Chinese spring wheat （Triticum aestivum L.） varieties were investigated. It was found that genotype, medium, auxin source a...The effects of auxins and media on callus induction from the mature and immature embryos of Chinese spring wheat （Triticum aestivum L.） varieties were investigated. It was found that genotype, medium, auxin source and concentration had the significant effects on the induction of embryogenic callus, explants germination and the increment of callus fresh weight. For immature embryos cultured on MS medium, 2 mg L^-1 of 2, 4-D was optimal, and the highest frequency of embryogenic callus （33.50%） was observed. For the mature embryos on N6 medium, 4 mg L^-1 of 2, 4-D was optimal. The frequency of embryogenic callus and increment of callus fresh weight on 2, 4, 5-T media were higher than those on 2, 4-D media, and in the presence of 2, 4, 5-T the precocious germination of explants for all genotypes were significantly suppressed. These results indicated that 2, 4, 5-T was superior to 2, 4-D and NAA in the culture of immature embryos. This is the first report about the effect of 2, 4, 5-T and NAA on wheat tissue culture, particularly in comparison with 2, 4-D in detail.展开更多
1AA 3-Indolylacetic acid, NAA a-Naphthylacetic acid and cytokinins in PESI culture medium were used in a study on the effects of plant hormones on the growth of free-living conchocelis of Porphyra yezoensis which show...1AA 3-Indolylacetic acid, NAA a-Naphthylacetic acid and cytokinins in PESI culture medium were used in a study on the effects of plant hormones on the growth of free-living conchocelis of Porphyra yezoensis which showed that its growth in medium with cytokinins, 1AA and NAA was more rapid than that in medium with non-phytohormones; that the optimal concentrations for promoting growth were 10μg/L for IAA and ZA (Zeatin), and 0.1 μg/L for BA 6-Benzyl amino purine and KIN 6-Furfurylamino- purine. Mix use of NAA, 1AA and cytokinins, NAA/ZA 1-1000/1μg/L, NAA/BA 10/1-1000 μg/L, NAA/KIN 1/1-1000 μg/L promoted growth. 1AA/ZA 0.1-1/0.1-1μg/L; 1AA/BA 0.1-1/0.1-10 μg/L IAA/KIN 1/0.1-1000μg/L also promoted growth.展开更多
Plant growth promotion indole-3-acetic acid (IAA) is the most abundant natural auxin that plays diverse roles in plant growth, development and plant immunity. Perturbing auxin homeostasis appears to be a common virule...Plant growth promotion indole-3-acetic acid (IAA) is the most abundant natural auxin that plays diverse roles in plant growth, development and plant immunity. Perturbing auxin homeostasis appears to be a common virulence mechanism, as many pathogens can synthesize auxin-like molecules. In other hand, the addition of plant growth promotion rhizobacteria (PGPR) that are able to produce auxins promotes plant growth and provides protection against pathogens. Techniques as high performance liquid chromatography (HPLC) and gas chromatography (GC) are used to quantify auxins produced by microorganism and plants at high precision and sensitivity, even though those techniques are expensive and require a big number of solvents. For these reasons, the aim of the present study was to develop a fast microplate technique for auxin detection, in Bacillus subtilis strains using salkowski reagent. For auxin quantification, calibration curves were done with alcohol, landy medium and water and the R2 were calculated. The microplate techniques were able to quantify auxin production by B. subtillis stains.展开更多
Experiments were performed to determine whether seed priming with different concentrations （100, 150, and 200 mg/L） of auxins （indoleacetic acid （IAA）, indolebutyric acid （IBA）, or their precursor tryptophane ...Experiments were performed to determine whether seed priming with different concentrations （100, 150, and 200 mg/L） of auxins （indoleacetic acid （IAA）, indolebutyric acid （IBA）, or their precursor tryptophane （Trp）） could alter salinity induced perturbances in salicylic acid and ion concentrations and, hence, growth in wheat （Triticum aestivum L.） cultivars, namely M.H.-97 （salt intolerant） and tnqtab-91 （salt tolerant）. Primed and non-primed seeds were sown in Petri dishes in a growth room, as well as in a field treated with 15 dS/m NaCl salinity. All priming agents, except IBA, increased the final germination percentage in both cultivars. The seedlings of either cultivar raised from Trp-treated seeds had greater dry biomass when under salt stress. In field experiments, Trp priming was much more effective in mediating the increase in grain yield, irrespective of the cultivar, under salt stress. The alleviatory effect of Trp was found to be associated with reduced uptake of Na^＋ in the roots and subsequent translocation to the shoots, as well as increased partitioning of Ca^＋ in the roots of salt-stressed wheat plants. Plants of both cultivars raised from Trp-and IAA-treated seeds accumulated free salicylic acid in their leaves when under salt stress. Overall, the Trp priming-induced improvement in germination and the subsequent growth of wheat plants could be related to ion homeostasis when under salt stress. The possible involvement of salicylic acid in the Trp priming-induced better growth under Conditions of salt stress is discussed.展开更多
Auxin is a phytohormone that is critical for plant growth and development.The molecular mechanisms underlying auxin biosynthesis,transport,and signaling are well understood.However,the complex mechanism by which auxin...Auxin is a phytohormone that is critical for plant growth and development.The molecular mechanisms underlying auxin biosynthesis,transport,and signaling are well understood.However,the complex mechanism by which auxin regulates plant volatile biosynthesis has seldom been studied.A growing array of unique auxin-related plant volatiles have recently been discovered.This study comprehensively reviews recent findings on auxin and auxin-related genes and their roles in the formation of plant volatiles.This study highlights the implications of exogenous auxin application,genes involved in auxin signaling transduction,and hormonal crosstalk during volatile compound biosynthesis in plants.Plant hormones facilitate the integration of multiple volatile signals to enable specific and appropriate responses to environmental changes.This will improve our overall understanding of the role of auxins in plant volatile compound metabolic pathways.Recent studies have delineated the considerable advancements in elucidating the intricate methods by which plants employ auxin regulatory pathways to modulate the release of volatile chemicals during development and growth,along with prospective research paths.展开更多
Gibberellins(GAs)and auxin play central regulatory roles in seed germination and root system development,respectively,so that the application of these phytohormones to crops would be worthwhile,with an increasing pote...Gibberellins(GAs)and auxin play central regulatory roles in seed germination and root system development,respectively,so that the application of these phytohormones to crops would be worthwhile,with an increasing potential demand in agriculture.However,there are few effective chemicals that simultaneously enhance both GA and auxin signaling.Here,we report on an artificial thiourea derivative chemical,Y21,that serves as both a GA-signaling agonist and an auxin analog,promoting seed germination and root development,as well as low-phosphorus tolerance.Phenotypic,biochemical,and genetic evidence demonstrated that Y21 enhances the interaction between GA and its receptor GID1C via the Val239 amino acid residue and consequently promotes degradation of the DELLA proteins REPRESSOR OF ga1-3(RGA)and RGA-LIKE 2.Furthermore,we found that Y21 interacts with the auxin receptor TIR1 via the Cys405 residue and thus promotes the turnover of the auxinresponsive Aux/IAA proteins.Consequently,Y21significantly increases low-phosphorus tolerance of treated plants by positively regulating lateral root development.To our knowledge,Y21 is the first GA-signaling agonist to be identified,and our results also demonstrate that this potent synthetic chemical,identified by chemical genetic screening,is effective at modulating plant development and stress tolerance.展开更多
The spatiotemporal regulation of polar auxin transport by PIN-FORMED(PIN)efflux carriers is essential for coordinating plant development with environmental cues.However,whether and how osmotic stress signaling affects...The spatiotemporal regulation of polar auxin transport by PIN-FORMED(PIN)efflux carriers is essential for coordinating plant development with environmental cues.However,whether and how osmotic stress signaling affects auxin transport to regulate plant stress adaptation remain largely unclear.In this study,we identify SnRK2.5,an abscisic acid–independent member of the SNF1-related protein kinase family,as a key molecular link between osmotic stress signaling and auxin transport regulation in Arabidopsis.Osmotic stress activates SnRK2.5,which directly phosphorylates PIN2 at Ser237 and Ser259.Genetic and cell biological analyses demonstrate that these phosphorylation events govern PIN2 vesicular trafficking,vacuolar targeting,and auxin transport activity.Disruption of these phosphorylation sites impairs PIN2-dependent auxin redistribution,thereby compromising root tropic responses and reducing osmotic stress tolerance.Our findings uncover a regulatory mechanism by which SnRK2.5-mediated phosphorylation of PIN2 dynamically adjusts auxin flux in response to water availability,representing a critical adaptive strategy that optimizes plant growth under osmotic stress.展开更多
Auxin regulates plant growth by integrating transport and signaling.Polar auxin transport establishes auxin gradients essential for development,with PIN-FORMED(PIN)efflux carriers generating directionality and AUXIN1/...Auxin regulates plant growth by integrating transport and signaling.Polar auxin transport establishes auxin gradients essential for development,with PIN-FORMED(PIN)efflux carriers generating directionality and AUXIN1/LIKE-AUX1(AUX1/LAX)influx carriers ensuring efficient uptake.Canonical signaling begins when auxin binds TRANSPORT INHIBITOR RESPONSE 1/AUXIN SIGNALING F-BOX PROTEIN(TIR1/AFB)receptors,the F-box component of the SKP1-CULLIN1-F-box(SCF)E3 ubiquitin ligase complex(Gray et al.,2001).Auxin promotes recruitment and degradation of AUXIN/INDOLE-3-ACETIC ACID(AUX/IAA)repressors,thereby releasing AUXIN RESPONSE FACTOR(ARF)to activate transcription(Gray et al.,2001).Recent discoveries have expended this model.Cryo-electron microscopy(cryo-EM)structures of AUX1 clarified its proton(H+)-coupled import(Yang et al.,2025),and TIR1 was shown to function as an adenylate cyclase(AC),producing c AMP to activate transcription(Chen et al.,2025).Synthetic promoter studies further revealed a bi-layer ARF/cis-element code shaping cel type-specific gene expression(Martin-Arevalil o et al.,2025).展开更多
Disruption of host physiological processes,leading to symptom expression,is a common hallmark during plant virus infections.The concept of“symptoms as strategy”is rapidly reshaping our understanding of plant virolog...Disruption of host physiological processes,leading to symptom expression,is a common hallmark during plant virus infections.The concept of“symptoms as strategy”is rapidly reshaping our understanding of plant virology.An emerging theme is that symptom expressions—such as stunting,curling,and yellowing,which devastate yield—may themselves be evolved viral adaptation strategies rather than collateral damage.展开更多
Carbohydrate partitioning from source to sink tissues is essential for plant growth and development.However,in maize(Zea mays L.),the molecular mechanisms by which callose synthase genes regulate this process remain l...Carbohydrate partitioning from source to sink tissues is essential for plant growth and development.However,in maize(Zea mays L.),the molecular mechanisms by which callose synthase genes regulate this process remain largely unexplored.This study demonstrates that mutation of maize callose synthase12(Zm Cals12)results in increased carbohydrate accumulation in photosynthetic leaves but decreased carbohydrate content in sink tissues,leading to plant dwarfing and male sterility.Histochemical β-glucuronidase(GUS)activity assay and m RNA in situ hybridization(ISH)revealed that Zm Cals12 expression mainly occurs in the vascular transport system.Zm Cals12 loss-of-function decreased callose synthase activity and callose deposition in plasmodesmatas(PDs)and surrounding phloem cells(PCs)of the vascular bundle.The drop-and-see(DANS)assay indicated reduced PD permeability in photosynthetic cells and diminished transport competence of leaf veins in Zmcals12 mutants,resulting in decreased symplastic transport.Paraffin section analysis revealed that less-developed vascular cells(VCs)in Zmcals12 mutants likely disrupted sugar transport,contributing to the pleiotropic phenotype.Furthermore,impaired sugar transport inhibited internode development by suppressing auxin(IAA)biosynthesis and signaling in Zmcals12 mutant.These findings elucidate the mechanism by which Zm Cals12-mediated callose deposition and symplastic transport regulate maize growth and development.展开更多
A 1050 bp up-stream regulatory fragment of the transcription factor gene NAC1in Arabidopsis thaliana was isolated using polymerase chain reaction(PCR)based techniques.Thefragment was used to substitute the 35S promote...A 1050 bp up-stream regulatory fragment of the transcription factor gene NAC1in Arabidopsis thaliana was isolated using polymerase chain reaction(PCR)based techniques.Thefragment was used to substitute the 35S promoter of the pBI121 plasmid to construct abate-glucuronidase gene(GUS)expression system.The construct was introduced into tobacco(Nico-tiana tabaccum)plants by the Agrobacterium-med\aled transferring method.GUS expressionpattern was studied by using the transgenic lines.The results showed that the GUS driven by theNAC1 up-stream regulatory region was specifically expressed in the root meristem region,basal areasof the lateral root primordium and the lateral roots.The GUS expression was induced by3-indolebutyric acid(IBA)and gibberellins(GA_3 and GA_(4+7)).The results indicated that theup-stream regulatory fragment of NAC1 responded to plant hormones.The fragment might be involved inboth auxins and gibberellins signaling in promoting the development of lateral roots.展开更多
Although class A auxin response factors(ARFs)are known to regulate adventitious root(AR)development through the canonical SCFTIR1-Aux/IAA-ARF signaling pathway,the regulatory role of class B ARFs in AR development rem...Although class A auxin response factors(ARFs)are known to regulate adventitious root(AR)development through the canonical SCFTIR1-Aux/IAA-ARF signaling pathway,the regulatory role of class B ARFs in AR development remains largely unclear.Therefore,this research focused on the role of class B ARF transcription factors in peach(Prunus persica‘Shengli')adventitious root formation.Here,we report the role of a class B ARF gene Pp ARF4 in adventitious root formation in peach.Comparative transcriptome and q RT-PCR analyses showed that the transcription of Pp ARF4 was significantly up-regulated in auxin-treated stem explants.Y2H assay showed that Pp ARF4 had no interaction with Pp IAAs(AUXIN/INDOLE ACETIC ACIDs).Pp ARF4 could bind the promoters of lateral root development gene Pp LBD16 and auxin transport gene Pp PIN1 to activate their transcription.Ectopic overexpression of Pp ARF4 and Pp LBD16 in Arabidopsis promoted AR development.Additionally,Pp ARF4 could act as a negative regulator of flavone synthesis and thus prevent the explants from browning.The results not only provide novel insights into the functions of ARFs in regulating plant growth and development,but will also be useful for fulfilling asexual propagation by stem cuttings in peach.展开更多
The phytohormone auxin exerts control over remarkable developmental processes in plants.It moves from cell to cell,resulting in the creation of both extracellular auxin and intracellular auxin,which are recognized by ...The phytohormone auxin exerts control over remarkable developmental processes in plants.It moves from cell to cell,resulting in the creation of both extracellular auxin and intracellular auxin,which are recognized by distinct auxin receptors.These two auxin signaling systems govern different auxin responses while working together to regulate plant development.In this review,we outline the latest research advancements in unraveling these auxin signaling pathways,encompassing auxin perception and signaling transductions.We emphasize the interaction between extracellular and intracellular auxin,which contributes to the intricate role of auxin in plant development.展开更多
The formation of root system architecture(RSA)plays a crucial role in plant growth.OsDRO1 is known to have a function in controlling RSA in rice,however,the role of potato StDRO2,a homolog of rice OsDRO1,in root growt...The formation of root system architecture(RSA)plays a crucial role in plant growth.OsDRO1 is known to have a function in controlling RSA in rice,however,the role of potato StDRO2,a homolog of rice OsDRO1,in root growth remains unclear.In this study,we obtained potato dro2 mutant lines by Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR-Associated 9(CRISPR/Cas9)-mediated genome editing system.The mutant lines were generated from a splicing defect of the StDRO2 intron 1,which causes a nonsense mutation in StDRO2.Furthermore,the secondary structure of StDRO2 mRNA analyzed with RNAfold Web Server was altered in the dro2 mutant.Mutation of StDRO2 conveys potato adaptation through changing the RSA via alteration of auxin transport under drought stress.The potato dro2 lines showed higher plant height,longer root length,smaller root growth angle and increased tuber weight than the wild-type.The alteration of RSA was associated with a disturbance of IAA distribution in the dro2 mutant,and the levels of StPIN7 and StPIN10 detected by using real-time PCR were up-regulated in the roots of potato dro2 lines grown under drought stress.Moreover,the microRNAs(miRNAs)PmiREN024536 and PmiREN024486 targeted the StDRO2 gene,and auxin positively and negatively regulated the expression of StDRO2 and the miRNAs PmiREN024536 and PmiREN024486,respectively,in the potato roots.Our data shows that a regulatory network involving auxin,StDRO2,PmiREN024536 and PmiREN024486 can control RSA to convey potato fitness under drought stress.展开更多
Protein biosynthesis by the ribosome is a fundamental biological process in living systems.Recent studies suggest that ribosomal subunits also play essential roles in cell growth and differentiation beyond their roles...Protein biosynthesis by the ribosome is a fundamental biological process in living systems.Recent studies suggest that ribosomal subunits also play essential roles in cell growth and differentiation beyond their roles in protein translation.The ribosomal subunit RPS6 has been studied for more than 50 years in various organisms,but little is known about its specific roles in certain signaling pathways.In this study,we focused on the functions of Arabidopsis RPS6A in auxin-related root growth and development.The rps6a mutant presented a series of auxin-deficient phenotypes,such as shortened primary roots,reduced lateral root numbers,and defective vasculatures.Treatment of the rps6a mutant with various concentrations of auxin and its analogs did not restore the root defect phenotypes,suggesting a defect in the auxin signaling pathway.Further cell biological and global transcriptome analyses revealed that auxin signaling was weakened in the rps6a mutant and that there was a reduced abundance of PIN-FORMED(PIN)auxin transporters.Our work provides insights into the role of the protein biosynthesis pathway involved in auxin signaling.展开更多
Highlights ZmMYC2 promoter contains favorable haplotypes selected during domestication,enhancing its expression level in modern maize.ZmMYC2 may balance the trade-off between growth and defense via jasmonate and auxin...Highlights ZmMYC2 promoter contains favorable haplotypes selected during domestication,enhancing its expression level in modern maize.ZmMYC2 may balance the trade-off between growth and defense via jasmonate and auxin signaling pathways.ZmMYC2 regulates drought-response genes(CER2 and TIP3c)to optimize drought stress resilience.展开更多
Grafting is an effective technique for increasing the resistance of vegetables to biotic and abiotic stresses.It has been widely applied to produce solanaceous and melon vegetables.Temperature is an important external...Grafting is an effective technique for increasing the resistance of vegetables to biotic and abiotic stresses.It has been widely applied to produce solanaceous and melon vegetables.Temperature is an important external factor affecting graft formation.However,the molecular mechanism by which external ambient temperature affects tomato graft formation remains unclear.In this study,we demonstrated that elevating ambient temperature during grafting to 35℃ for more than 24 h after grafting accelerated vascular reconnection.We generated self-or heterografted combinations between phyB1B2 and pif4 loss-of-function mutant and wild-type plants,and were mutants unresponsive to graft formation at elevated ambient temperature.In addition,elevated ambient temperature induced SlPIF4 expression during grafting.SlPIF4 directly binds the promoters of auxin biosynthesis genes SlYUCCAs and activates their expression.Further investigation revealed auxin accumulation in the graft junction under elevated ambient temperature.The results illuminate the mechanism by which the PHYB-PIF4-auxin module promotes tomato graft formation in response to elevated ambient temperature.展开更多
基金the provision of funds in the form of a research project(No.20-1155/R&D/07)awarded to FA
文摘Akram MUHAMMAD, Aftab FAHEEM＊Abstract In this presentation, we report on de novo and axillary shoot regeneration and rooting of shoots maintained over a long term, from cultures of Tectona grandis L. Shoot-tips of teak shoots forced from epicormic buds were used as the starting material for axenie shoot-culture establishment. Long term maintenance of such axenic shoot cultures was carried out by regular sub-culturing on MS media supplemented with N6-benzyleadenine （BA, 8.8 μmol·L^-1） and indole-3-butyric acid （IBA, 2 μmol·L ^1） for 24 months. Vigorously growing shoot tips （2-3 cm long） were inoculated on the MS basal medium supplemented with different concentrations （0, 1, 2, 4, 6, 8 or 10 p.mol-L-~） of either [BA or a-naphthaleneacetic acid （NAA） for rooting. Axillary and de novo shoots were de- veloped from axillary and cut basal ends of shoots, respectively. Shoots growing on auxins were further sub-cultured （every 15 days） and maintained for 45 days. The greatest number of de novo （5.06） as well as axillary shoots （2.85） was observed on the MS medium supplemented with 10 μmol-L^-1 NAA or 8 μmol·L^-1 IBA, respectively, after 45 days. The combinations of both IBA （μmol·L^-1） ＋ NAA （μmol·L^-1） were tested at different concentrations （4 ＋ 4, 6 ＋ 6, 8 ＋ 8） supplemented to a half strength MS basal medium with 0.1% activated charcoal for rooting of decapitated and non-decapitated de novo and axillary shoots. Rooting from non-decapitated de novo shoots was highest （93.33%） with a mean number of roots of 4.61 on this medium, supplemented with 6 μmol·L^-1 IBA ＋ 6 gmol.L l NAA, after 36 days of initial culture. Individual auxin, however, was not effective for root induction. Rooted shoots were acclimatized in a green house and after four weeks plantlets were transferred to the field.
文摘The present study reports an efficient protocol for in vitro propagation of Thymus vulgaris L., an aromatic and medicinal plant in Morocco. Initially, we performed in vitro multiplication of Thymus vulgaris explants existing in the laboratory and obtained from micropropagation by shoot tip culture. Afterwards, we have evaluated the effect of six macronutrients. After that, seven cytokinins (Kin, BAP, 2iP, DPU, Adenine, Zeatine and TDZ) in three different concentrations (0.46, 0.93, 2.32 μM) have been evaluated to optimize cultures multiplication and elongation. Moreover, the effect of three auxins (IAA, IBA and NAA) at 0.57 μM, combined to 4 cytokinins (Kin, BAP, DPU and Ad.) at 0.46 μM, on shoot rooting has been studied. Thereby, MS medium has been proved the most favorable for plantlets growing. Also, we found that the addition of certain cytokinins, specifically 0.46 Kin, 0.46 and 0.93 BAP, 0.46 2iP, 0.46 DPU, 0.46 Ad. and 0.46 Zeat., ensures better multiplication and growth of vitroplants. In addition, multiplication and rooting of cultures were well optimized after addition 0.46 Kin + 0.57 IAA or NAA, 0.46 DPU + 0.57 IBA and 0.46 Ad. + 0.57 IBA combinations to the culture medium. Lastly, plantlets with roots were successfully acclimatized to ex-vitro conditions and these latter served as a source to establish in vitro culture again.
文摘An efficient in vitro method for rapid vegetative propagation of Bienertia sinuspersici, one of four terrestrial species of family Chenopodiaceae capable of performing C4 photosynthesis within a single cell, was developed. Cuttings of B. sinuspersici were used to examine the effects of Murashige and Skoog (MS) media strength and auxins on adventitious root formation. Half-strength MS medium was determined to be ideal for adventitious root formation in Bienertia cuttings. Although cuttings cultured in medium containing 5.0 mg/L α-naphthalene acetic acid (NAA) promoted the highest number of adventitious roots, cuttings cultured in medium supplemented with 1.0 mg/L indole-3-butyric acid (IBA) produced the longest adventitious roots and had the highest survival rate upon transplanting to soil. Histological analysis revealed variations in the root anatomy generated by the various auxins which may affect adventitious root formation and subsequent establishment of cuttings in soil. Overall, the established procedure provides a simple and cost-effective means for the rapid propagation of the single-cell C4 species B. sinuspersici.
基金the National High Tech R&D Program of China(863 Program,2003AA207100)the Foundation for the Author of National Excellent Doctoral Dissertation of P R China(200357) the Program forChangjiang Scholars and Innovative Research Team inUniversity(IRT0453).
文摘The effects of auxins and media on callus induction from the mature and immature embryos of Chinese spring wheat （Triticum aestivum L.） varieties were investigated. It was found that genotype, medium, auxin source and concentration had the significant effects on the induction of embryogenic callus, explants germination and the increment of callus fresh weight. For immature embryos cultured on MS medium, 2 mg L^-1 of 2, 4-D was optimal, and the highest frequency of embryogenic callus （33.50%） was observed. For the mature embryos on N6 medium, 4 mg L^-1 of 2, 4-D was optimal. The frequency of embryogenic callus and increment of callus fresh weight on 2, 4, 5-T media were higher than those on 2, 4-D media, and in the presence of 2, 4, 5-T the precocious germination of explants for all genotypes were significantly suppressed. These results indicated that 2, 4, 5-T was superior to 2, 4-D and NAA in the culture of immature embryos. This is the first report about the effect of 2, 4, 5-T and NAA on wheat tissue culture, particularly in comparison with 2, 4-D in detail.
基金The research was supported by a grant from the Chinese Aeademy of Scicnes
文摘1AA 3-Indolylacetic acid, NAA a-Naphthylacetic acid and cytokinins in PESI culture medium were used in a study on the effects of plant hormones on the growth of free-living conchocelis of Porphyra yezoensis which showed that its growth in medium with cytokinins, 1AA and NAA was more rapid than that in medium with non-phytohormones; that the optimal concentrations for promoting growth were 10μg/L for IAA and ZA (Zeatin), and 0.1 μg/L for BA 6-Benzyl amino purine and KIN 6-Furfurylamino- purine. Mix use of NAA, 1AA and cytokinins, NAA/ZA 1-1000/1μg/L, NAA/BA 10/1-1000 μg/L, NAA/KIN 1/1-1000 μg/L promoted growth. 1AA/ZA 0.1-1/0.1-1μg/L; 1AA/BA 0.1-1/0.1-10 μg/L IAA/KIN 1/0.1-1000μg/L also promoted growth.
文摘Plant growth promotion indole-3-acetic acid (IAA) is the most abundant natural auxin that plays diverse roles in plant growth, development and plant immunity. Perturbing auxin homeostasis appears to be a common virulence mechanism, as many pathogens can synthesize auxin-like molecules. In other hand, the addition of plant growth promotion rhizobacteria (PGPR) that are able to produce auxins promotes plant growth and provides protection against pathogens. Techniques as high performance liquid chromatography (HPLC) and gas chromatography (GC) are used to quantify auxins produced by microorganism and plants at high precision and sensitivity, even though those techniques are expensive and require a big number of solvents. For these reasons, the aim of the present study was to develop a fast microplate technique for auxin detection, in Bacillus subtilis strains using salkowski reagent. For auxin quantification, calibration curves were done with alcohol, landy medium and water and the R2 were calculated. The microplate techniques were able to quantify auxin production by B. subtillis stains.
文摘Experiments were performed to determine whether seed priming with different concentrations （100, 150, and 200 mg/L） of auxins （indoleacetic acid （IAA）, indolebutyric acid （IBA）, or their precursor tryptophane （Trp）） could alter salinity induced perturbances in salicylic acid and ion concentrations and, hence, growth in wheat （Triticum aestivum L.） cultivars, namely M.H.-97 （salt intolerant） and tnqtab-91 （salt tolerant）. Primed and non-primed seeds were sown in Petri dishes in a growth room, as well as in a field treated with 15 dS/m NaCl salinity. All priming agents, except IBA, increased the final germination percentage in both cultivars. The seedlings of either cultivar raised from Trp-treated seeds had greater dry biomass when under salt stress. In field experiments, Trp priming was much more effective in mediating the increase in grain yield, irrespective of the cultivar, under salt stress. The alleviatory effect of Trp was found to be associated with reduced uptake of Na^＋ in the roots and subsequent translocation to the shoots, as well as increased partitioning of Ca^＋ in the roots of salt-stressed wheat plants. Plants of both cultivars raised from Trp-and IAA-treated seeds accumulated free salicylic acid in their leaves when under salt stress. Overall, the Trp priming-induced improvement in germination and the subsequent growth of wheat plants could be related to ion homeostasis when under salt stress. The possible involvement of salicylic acid in the Trp priming-induced better growth under Conditions of salt stress is discussed.
基金supported by the National Natural Science Foundation of China(Grant Nos.W2433051,32272663,32302520,and 32060655)National Key Research and Development Program(Grant No.2023YFD2300800)+3 种基金the Guangzhou Science and Technology Project(Grant No.202206010023)Yunnan Provincial Science and Technology Department Local Universities Joint Project(Grant No.202101BA070001-166)China Litchi and Longan Industry Technology Research System(CARS-32-08),Talent Introduction Project of Kunming University(Grant No.XJ20220003)Yunnan Provincial Natural Science Basic Research Fund General Program(Grant No.202501AT070058).
文摘Auxin is a phytohormone that is critical for plant growth and development.The molecular mechanisms underlying auxin biosynthesis,transport,and signaling are well understood.However,the complex mechanism by which auxin regulates plant volatile biosynthesis has seldom been studied.A growing array of unique auxin-related plant volatiles have recently been discovered.This study comprehensively reviews recent findings on auxin and auxin-related genes and their roles in the formation of plant volatiles.This study highlights the implications of exogenous auxin application,genes involved in auxin signaling transduction,and hormonal crosstalk during volatile compound biosynthesis in plants.Plant hormones facilitate the integration of multiple volatile signals to enable specific and appropriate responses to environmental changes.This will improve our overall understanding of the role of auxins in plant volatile compound metabolic pathways.Recent studies have delineated the considerable advancements in elucidating the intricate methods by which plants employ auxin regulatory pathways to modulate the release of volatile chemicals during development and growth,along with prospective research paths.
基金supported by grants from the National Natural Science Foundation of China(32470364,31872850,and 31872804)the Natural Science Basic Research Program of Shaanxi(2025JC-JCQN-056 and 2024JC-YBMS-151)+2 种基金the Guangdong Basic and Applied Basic Research Foundation(2025A1515012749)the China Postdoctoral Science Foundation(2025M774348)the Shaanxi Fundamental Science Research Project for Chemistry&Biology(22JHZ007and 22JHQ054)。
文摘Gibberellins(GAs)and auxin play central regulatory roles in seed germination and root system development,respectively,so that the application of these phytohormones to crops would be worthwhile,with an increasing potential demand in agriculture.However,there are few effective chemicals that simultaneously enhance both GA and auxin signaling.Here,we report on an artificial thiourea derivative chemical,Y21,that serves as both a GA-signaling agonist and an auxin analog,promoting seed germination and root development,as well as low-phosphorus tolerance.Phenotypic,biochemical,and genetic evidence demonstrated that Y21 enhances the interaction between GA and its receptor GID1C via the Val239 amino acid residue and consequently promotes degradation of the DELLA proteins REPRESSOR OF ga1-3(RGA)and RGA-LIKE 2.Furthermore,we found that Y21 interacts with the auxin receptor TIR1 via the Cys405 residue and thus promotes the turnover of the auxinresponsive Aux/IAA proteins.Consequently,Y21significantly increases low-phosphorus tolerance of treated plants by positively regulating lateral root development.To our knowledge,Y21 is the first GA-signaling agonist to be identified,and our results also demonstrate that this potent synthetic chemical,identified by chemical genetic screening,is effective at modulating plant development and stress tolerance.
基金supported by grants from the National Key R&D Program of China(2022YFA1303400)the Fundamental Research Funds for the Central Universities(KJJQ2024007)+2 种基金the National Natural Science Foundation of China(32270301)to Q.Z.the Pinduoduo-China Agricultural University Research Fund(PC2024B01005)the Hainan Provincial Natural Science Foundation of China(323CXTD379)to J.Z.
文摘The spatiotemporal regulation of polar auxin transport by PIN-FORMED(PIN)efflux carriers is essential for coordinating plant development with environmental cues.However,whether and how osmotic stress signaling affects auxin transport to regulate plant stress adaptation remain largely unclear.In this study,we identify SnRK2.5,an abscisic acid–independent member of the SNF1-related protein kinase family,as a key molecular link between osmotic stress signaling and auxin transport regulation in Arabidopsis.Osmotic stress activates SnRK2.5,which directly phosphorylates PIN2 at Ser237 and Ser259.Genetic and cell biological analyses demonstrate that these phosphorylation events govern PIN2 vesicular trafficking,vacuolar targeting,and auxin transport activity.Disruption of these phosphorylation sites impairs PIN2-dependent auxin redistribution,thereby compromising root tropic responses and reducing osmotic stress tolerance.Our findings uncover a regulatory mechanism by which SnRK2.5-mediated phosphorylation of PIN2 dynamically adjusts auxin flux in response to water availability,representing a critical adaptive strategy that optimizes plant growth under osmotic stress.
基金Young Scientists Fund of the National Natural Science Foundation of China(61572004,L.L.,32202496,H.H.)。
文摘Auxin regulates plant growth by integrating transport and signaling.Polar auxin transport establishes auxin gradients essential for development,with PIN-FORMED(PIN)efflux carriers generating directionality and AUXIN1/LIKE-AUX1(AUX1/LAX)influx carriers ensuring efficient uptake.Canonical signaling begins when auxin binds TRANSPORT INHIBITOR RESPONSE 1/AUXIN SIGNALING F-BOX PROTEIN(TIR1/AFB)receptors,the F-box component of the SKP1-CULLIN1-F-box(SCF)E3 ubiquitin ligase complex(Gray et al.,2001).Auxin promotes recruitment and degradation of AUXIN/INDOLE-3-ACETIC ACID(AUX/IAA)repressors,thereby releasing AUXIN RESPONSE FACTOR(ARF)to activate transcription(Gray et al.,2001).Recent discoveries have expended this model.Cryo-electron microscopy(cryo-EM)structures of AUX1 clarified its proton(H+)-coupled import(Yang et al.,2025),and TIR1 was shown to function as an adenylate cyclase(AC),producing c AMP to activate transcription(Chen et al.,2025).Synthetic promoter studies further revealed a bi-layer ARF/cis-element code shaping cel type-specific gene expression(Martin-Arevalil o et al.,2025).
基金supported by the National Natural Science Foundation of China(32272482)the Innovation Research 2035 Pilot Plan of Southwest University(SWU-XDZD22002).
文摘Disruption of host physiological processes,leading to symptom expression,is a common hallmark during plant virus infections.The concept of“symptoms as strategy”is rapidly reshaping our understanding of plant virology.An emerging theme is that symptom expressions—such as stunting,curling,and yellowing,which devastate yield—may themselves be evolved viral adaptation strategies rather than collateral damage.
基金supported by grants from the National Natural Science Foundation of China(31771876)the Biological Breeding Program of State Key Laboratory of Sichuan Agricultural University,China(SKL-ZY202234)the Sichuan Province Science and Technology Program,China(2021YFYZ0011 and 2021YFYZ0017)。
文摘Carbohydrate partitioning from source to sink tissues is essential for plant growth and development.However,in maize(Zea mays L.),the molecular mechanisms by which callose synthase genes regulate this process remain largely unexplored.This study demonstrates that mutation of maize callose synthase12(Zm Cals12)results in increased carbohydrate accumulation in photosynthetic leaves but decreased carbohydrate content in sink tissues,leading to plant dwarfing and male sterility.Histochemical β-glucuronidase(GUS)activity assay and m RNA in situ hybridization(ISH)revealed that Zm Cals12 expression mainly occurs in the vascular transport system.Zm Cals12 loss-of-function decreased callose synthase activity and callose deposition in plasmodesmatas(PDs)and surrounding phloem cells(PCs)of the vascular bundle.The drop-and-see(DANS)assay indicated reduced PD permeability in photosynthetic cells and diminished transport competence of leaf veins in Zmcals12 mutants,resulting in decreased symplastic transport.Paraffin section analysis revealed that less-developed vascular cells(VCs)in Zmcals12 mutants likely disrupted sugar transport,contributing to the pleiotropic phenotype.Furthermore,impaired sugar transport inhibited internode development by suppressing auxin(IAA)biosynthesis and signaling in Zmcals12 mutant.These findings elucidate the mechanism by which Zm Cals12-mediated callose deposition and symplastic transport regulate maize growth and development.
基金supported by the National Natural Science Foundation of China(Grant No.30200169)the Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20010019008).
文摘A 1050 bp up-stream regulatory fragment of the transcription factor gene NAC1in Arabidopsis thaliana was isolated using polymerase chain reaction(PCR)based techniques.Thefragment was used to substitute the 35S promoter of the pBI121 plasmid to construct abate-glucuronidase gene(GUS)expression system.The construct was introduced into tobacco(Nico-tiana tabaccum)plants by the Agrobacterium-med\aled transferring method.GUS expressionpattern was studied by using the transgenic lines.The results showed that the GUS driven by theNAC1 up-stream regulatory region was specifically expressed in the root meristem region,basal areasof the lateral root primordium and the lateral roots.The GUS expression was induced by3-indolebutyric acid(IBA)and gibberellins(GA_3 and GA_(4+7)).The results indicated that theup-stream regulatory fragment of NAC1 responded to plant hormones.The fragment might be involved inboth auxins and gibberellins signaling in promoting the development of lateral roots.
基金supported by the National Natural Science Foundation of China(Grant Nos.32272690 and 32272687)the China Agriculture Research System(Grant No.CARS-30)Hubei Hongshan Laboratory(Grant No.2021hszd017)。
文摘Although class A auxin response factors(ARFs)are known to regulate adventitious root(AR)development through the canonical SCFTIR1-Aux/IAA-ARF signaling pathway,the regulatory role of class B ARFs in AR development remains largely unclear.Therefore,this research focused on the role of class B ARF transcription factors in peach(Prunus persica‘Shengli')adventitious root formation.Here,we report the role of a class B ARF gene Pp ARF4 in adventitious root formation in peach.Comparative transcriptome and q RT-PCR analyses showed that the transcription of Pp ARF4 was significantly up-regulated in auxin-treated stem explants.Y2H assay showed that Pp ARF4 had no interaction with Pp IAAs(AUXIN/INDOLE ACETIC ACIDs).Pp ARF4 could bind the promoters of lateral root development gene Pp LBD16 and auxin transport gene Pp PIN1 to activate their transcription.Ectopic overexpression of Pp ARF4 and Pp LBD16 in Arabidopsis promoted AR development.Additionally,Pp ARF4 could act as a negative regulator of flavone synthesis and thus prevent the explants from browning.The results not only provide novel insights into the functions of ARFs in regulating plant growth and development,but will also be useful for fulfilling asexual propagation by stem cuttings in peach.
基金supported by the National Natural Science Foundation of China(32130010).
文摘The phytohormone auxin exerts control over remarkable developmental processes in plants.It moves from cell to cell,resulting in the creation of both extracellular auxin and intracellular auxin,which are recognized by distinct auxin receptors.These two auxin signaling systems govern different auxin responses while working together to regulate plant development.In this review,we outline the latest research advancements in unraveling these auxin signaling pathways,encompassing auxin perception and signaling transductions.We emphasize the interaction between extracellular and intracellular auxin,which contributes to the intricate role of auxin in plant development.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.32260085,31860064,31660501,31970609,32260718 and 31901870)the Key Projects of the Applied Basic Research Plan of Yunnan Province(Grant No.202301AS070082)+3 种基金the Start-up fund from Xishuangbanna Tropical Botanical Garden,the‘Top Talents Program in Science and Technology’from Yunnan Province,the Major Science and Technology Project in Yunnan Province(Grant Nos.202102AE090042 and 202202AE090036)the Young and Middle-Aged Academic and Technical Leaders Reserve Talent Program in Yunnan Province(Grant No.202205AC160076)China Postdoctoral Science Foundation(Grant No.2019M653849XB)the High-level Talents Introduction Plan of Yunnan Province-Young Talents Special Project。
文摘The formation of root system architecture(RSA)plays a crucial role in plant growth.OsDRO1 is known to have a function in controlling RSA in rice,however,the role of potato StDRO2,a homolog of rice OsDRO1,in root growth remains unclear.In this study,we obtained potato dro2 mutant lines by Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR-Associated 9(CRISPR/Cas9)-mediated genome editing system.The mutant lines were generated from a splicing defect of the StDRO2 intron 1,which causes a nonsense mutation in StDRO2.Furthermore,the secondary structure of StDRO2 mRNA analyzed with RNAfold Web Server was altered in the dro2 mutant.Mutation of StDRO2 conveys potato adaptation through changing the RSA via alteration of auxin transport under drought stress.The potato dro2 lines showed higher plant height,longer root length,smaller root growth angle and increased tuber weight than the wild-type.The alteration of RSA was associated with a disturbance of IAA distribution in the dro2 mutant,and the levels of StPIN7 and StPIN10 detected by using real-time PCR were up-regulated in the roots of potato dro2 lines grown under drought stress.Moreover,the microRNAs(miRNAs)PmiREN024536 and PmiREN024486 targeted the StDRO2 gene,and auxin positively and negatively regulated the expression of StDRO2 and the miRNAs PmiREN024536 and PmiREN024486,respectively,in the potato roots.Our data shows that a regulatory network involving auxin,StDRO2,PmiREN024536 and PmiREN024486 can control RSA to convey potato fitness under drought stress.
基金supported by the National Natural Science Foundation of China(32321001)the Forestry Bureau of Anhui Province(AHLYJBGS-2024-01)+3 种基金the Center for Advanced Interdisciplinary Science and Biomedicine of IHM,the Division of Life Sciences and Medicine,the University of Science and Technology of China(QYPY20220012)the USTC Research Funds of the Double First-Class Initiative(YD9100002016)start-up funding from the University of Science and Technology of China and the Chinese Academy of Sciences(GG9100007007,KY9100000026,KY9100000051,KJ2070000079)the Fundamental Research Funds for the Central Universities(WK9100000021)。
文摘Protein biosynthesis by the ribosome is a fundamental biological process in living systems.Recent studies suggest that ribosomal subunits also play essential roles in cell growth and differentiation beyond their roles in protein translation.The ribosomal subunit RPS6 has been studied for more than 50 years in various organisms,but little is known about its specific roles in certain signaling pathways.In this study,we focused on the functions of Arabidopsis RPS6A in auxin-related root growth and development.The rps6a mutant presented a series of auxin-deficient phenotypes,such as shortened primary roots,reduced lateral root numbers,and defective vasculatures.Treatment of the rps6a mutant with various concentrations of auxin and its analogs did not restore the root defect phenotypes,suggesting a defect in the auxin signaling pathway.Further cell biological and global transcriptome analyses revealed that auxin signaling was weakened in the rps6a mutant and that there was a reduced abundance of PIN-FORMED(PIN)auxin transporters.Our work provides insights into the role of the protein biosynthesis pathway involved in auxin signaling.
基金supported by the National Key Research and Development Program of China(2023YFD1200503 to Shuai Ma and 2021YFD1200700 to Tianyu Wang)。
文摘Highlights ZmMYC2 promoter contains favorable haplotypes selected during domestication,enhancing its expression level in modern maize.ZmMYC2 may balance the trade-off between growth and defense via jasmonate and auxin signaling pathways.ZmMYC2 regulates drought-response genes(CER2 and TIP3c)to optimize drought stress resilience.
基金supported by China Agriculture Research System of MOF and MARA(Grant No.CARS23-B10)The Major Science and Technology Projects in Hainan Province(Grant No.ZDKJ2021005)+1 种基金Key R&D projects in Shandong Province(Grant No.LJNY202106)Central Public-interest Scientific Institution Basal Research Fund(Grant No.IVF-BRF2023006)。
文摘Grafting is an effective technique for increasing the resistance of vegetables to biotic and abiotic stresses.It has been widely applied to produce solanaceous and melon vegetables.Temperature is an important external factor affecting graft formation.However,the molecular mechanism by which external ambient temperature affects tomato graft formation remains unclear.In this study,we demonstrated that elevating ambient temperature during grafting to 35℃ for more than 24 h after grafting accelerated vascular reconnection.We generated self-or heterografted combinations between phyB1B2 and pif4 loss-of-function mutant and wild-type plants,and were mutants unresponsive to graft formation at elevated ambient temperature.In addition,elevated ambient temperature induced SlPIF4 expression during grafting.SlPIF4 directly binds the promoters of auxin biosynthesis genes SlYUCCAs and activates their expression.Further investigation revealed auxin accumulation in the graft junction under elevated ambient temperature.The results illuminate the mechanism by which the PHYB-PIF4-auxin module promotes tomato graft formation in response to elevated ambient temperature.
