Regulation of the growth of sprouting roots of black locust seedlings using root barrier panels

How can we regulate an invasive alien species of high commercial value?Black locust(Robinia pseudoacacia L.)has a unique capacity for seed dispersal and high germination.Field surveys indicate that black locust increases its growing area with sprouting roots and the elongation of horizontal roots at a soil depth of 10 cm.Therefore,a method to regulate the development of horizontal roots could be eff ective in slowing the invasiveness of black locust.In this study,root barrier panels were tested to inhibit the growth of horizontal roots.Since it is labor intensive to observe the growth of roots in the fi eld,it was investigated in a nursery setting.The decrease in secondary fl ush,an increase in yellowed leafl ets,and the height in the seedlings were measured.Installing root barrier panels to a depth of 30 cm eff ectively inhibit the growth of horizontal roots of young black locust.

Identification of KASP markers and putative genes for pre-harvest sprouting resistance in common wheat(Triticum aestivum L.)

Common wheat(Triticum aestivum L.)is the most important crop in the world and a typical allopolyploid with a large and complex genome.Pre-harvest sprouting(PHS)leads to a significant reduction in grain quality worldwide.PHS is a complex trait with related QTL located on different chromosomes.However,the study of markers and genes related to PHS resistance is limited especially for whitegrained wheat.Four pairs of near isogenic lines(NILs)from a white-grained wheat cross of Chara
DM5637B*8 targeting a major QTL for PHS resistance(Qphs.ccsu-3A.1)on wheat chromosme 3AL were genotyped using the 90K SNP Illumina iSelect array.Ten SNPs were identified,with a 75%-100%consistency between genotype and phenotype in the resistant or susceptible isolines.The 10 SNPs were converted to cost-effective kompetitive allele-specific PCR(KASP)markers.Screening of 48 wheat cultivars with different phenotypes of PHS identified four KASP markers with 81.3%-85.4%conformity between genotype and phenotype.Further investigation revealed that the four SNPs(BS00022245_51,Kukri_c49927_151,BS00022884_51 and BS00110550_51)corresponding to the four validated KASP markers are residing in three independent genes(TraesCS3A03G1072800,TraesCS3A03G1072400,TraesCS3A03G1071800)close to each other with a distance of 4.28-4.48 Mb to the targeted QTL.These three annotated genes have potential functions related to PHS resistance.Our study revealed that combined use of NILs and the 90K SNP chip is a powerful approach for developing KASP markers and mining functional genes in wheat.The KASP markers for PHS resistance on chromosome 3AL are useful for high-throughput evaluation and marker-assisted selection,and the three identified genes could lead to a better understanding of the genetic pathways controlling PHS.

QTL mapping for pre-harvest sprouting in a recombinant inbred line population of elite wheat varieties Zhongmai 578 and Jimai 22

Pre-harvest sprouting(PHS)is one of the serious global issues in wheat production.Identification of quantitative trait loci(QTL)and closely-linked markers is greatly helpful for wheat improvement.In the present study,a recombinant inbred line(RIL)population derived from the cross of Zhongmai 578(ZM578)/Jimai 22(JM22)and parents were phenotyped in five environments and genotyped by the wheat 50 K single-nucleotide polymorphism(SNP)array.Two QTL of germination index(GI),QGI.caas-3A and QGI.caas-5A,were detected,explaining 4.33%–5.58%and 4.43%–8.02%of the phenotypic variances,respectively.The resistant effect of QGI.caas-3A was contributed by JM22,whereas that of QGI.caas.5A was from ZM578.The two QTL did not correspond to any previously identified genes or genetic loci for PHSrelated traits according to their locations in the Chinese Spring reference genome,indicating that they are likely to be new loci for PHS resistance.Four kompetitive allele-specific PCR(KASP)markers K_AX-109605367and K_AX-179559687 flanking QGI.caas-3A,and K_AX-111258240 and K_AX-109402944flanking QGI.caas-5A,were developed and validated in a natural population of 100 wheat cultivars.The distribution frequency of resistance alleles at Qphs.caas-3A and Qphs.caas-5A loci were 82.7%and57.1%,respectively,in the natural population.These findings provide new QTL and tightly linked KASP markers for improvement of PHS resistance in wheat.

Evaluation of Pre-Harvest Sprouting(PHS)Resistance and Screening of High-Quality Varieties from Thirty-Seven Quinoa(Chenopodium quinoa Willd.)Resources in Chengdu Plain

Pre-harvest sprouting(PHS)will have a serious effect both on the yield and quality of quinoa(Chenopodium quinoaWilld.).It is crucial to select and breed quinoa varieties with PHS resistance and excellent agronomic traits for guidance production and utilization of quinoa.A comprehensive evaluation of the PHS resistance and agronomic traits of 37 species of quinoa resources was conducted in Chengdu Plain.The evaluation used various methods,including grain germination rate(GR),grain germination index(GI),total spike germination rate(SR),total grain germination index(SI),grey correlation analysis(GCA),cluster analysis and correlation analysis.Results showed significant differences in PHS resistance and agronomic traits amongst the 37 quinoa resources.CDU-23 was most resistant to PHS within 24 h,with a germination rate of 2.67%and 0%according to the GR and SR results,respectively.However,in the same time,CDU-31 showed the maximum susceptibility to PHS based on the SR of 31.07%,while CDU-34 was the most sensitive to PHS according to the GR of 100%.The comprehensive evaluation identified one and nine kinds of high resistance species for grain and whole spike germination,respectively.In both cases,the coefficients of variation(CV)for these parameters were 34.78%and 82.13%,respectively.GCA results showed that the magnitude of the association between each trait and yield in the thirty-seven quinoa resources was in the following order:thousand grain weight>seed length>seed area>seed width.Although the seed weight of CDU-18 reached 3.7010 g,the seed weight of CDU-5 was only 1.6030 g.However,the size of the seeds,their width and area did not correlate with their 1000-grain weight.There was a complex correlation between PHS resistance index and agronomic traits.Based on clustering analysis,thirty-seven quinoa resources were classified into three taxa.It was found that various taxa differed in PHS resistance and agronomic traits.Several comparisons of the aggregated data led to the selection of five varieties of quinoa,of which CDU-2 presented excellent agronomic qualities and strong PHS resistance.This study has provided a reference for breeding excellent quinoa varieties with PHS resistance.

Experimental Research on Four Season Soilless Cultivation of the Sprouting Seedlings of Toona sinensis in Chongqing

Using seed sowing cultivation method, the four-season soilless cultivation of the sprouting seedlings of Toona sinensis was carried out with different germination accelerating treatments, cultivation substrates, cultivation environment and management technologies by using the corresponding treatment methods in different seasons, so as to produce the sprouting vegetable products of T. sinensis which was not restricted by seasons. The test results showed that using the mixed substrate of pedite and vermiculite in winter and spring can keep moisture but not too high, and the produced sprout vegetable had good quality and high yield.

Effects of Fragmentation Intensity of Perennial Roots and Their Burial Depth on Sprouting and Early Growth of Alternanthera philoxeroides(Mart.)Griseb

[Objective] The aim was to provide theoretical basis for the prevention and control of the invasion of Alternanthera philoxeroides（Mart.）Griseb.[Method] Effects of fragmentation intensity of fresh roots and their burial depth on sprouting and early growth of A.philoxeroides were studied by control test.[Result] More sprouts of A.philoxeroides emerged when the fragmentation intensity of fresh roots was higher,while if the fragmentation intensity of fresh roots was lower,the early growth of A.philoxeroides was more rapid.The soil buried depth had significant effect on fresh root sprouts＇ emergence,but once fresh root sprouts could reach the soil surface and were given enough growth time,even if the fresh roots were buried in different depths,soil buried depth had no significant effect on its young plant growth.[Conclusion] If different fragmentation intensities of fresh roots present,there is a kind of trade-off strategy between root sprouts＇ emergence and plant＇ early growth,by which A.philoxeroides can invade new habitat successfully.To control the invasion of A.philoxeroides,it is critical to prevent its fresh root sprouts from emerging to soil surface,that is,to bury the fresh roots at a further soil depth.

Axonal regeneration and sprouting as a potential therapeutic target for nervous system disorders

Nervous system disorders are prevalent health issues that will only continue to increase in frequency as the population ages.Dying-back axonopathy is a hallmark of many neurologic diseases and leads to axonal disconnection from their targets,which in turn leads to functional impairment.During the course of many of neurologic diseases,axons can regenerate or sprout in an attempt to reconnect with the target and restore synapse function.In amyotrophic lateral sclerosis(ALS),distal motor axons retract from neuromuscular junctions early in the disease-course before significant motor neuron death.There is evidence of compensatory motor axon sprouting and reinnervation of neuromuscular junctions in ALS that is usually quickly overtaken by the disease course.Potential drugs that enhance compensatory sprouting and encourage reinnervation may slow symptom progression and retain muscle function for a longer period of time in ALS and in other diseases that exhibit dying-back axonopathy.There remain many outstanding questions as to the impact of distinct disease-causing mutations on axonal outgrowth and regeneration,especially in regards to motor neurons derived from patient induced pluripotent stem cells.Compartmentalized microfluidic chambers are powerful tools for studying the distal axons of human induced pluripotent stem cells-derived motor neurons,and have recently been used to demonstrate striking regeneration defects in human motor neurons harboring ALS disease-causing mutations.Modeling the human neuromuscular circuit with human induced pluripotent stem cells-derived motor neurons will be critical for developing drugs that enhance axonal regeneration,sprouting,and reinnervation of neuromuscular junctions.In this review we will discuss compensatory axonal sprouting as a potential therapeutic target for ALS,and the use of compartmentalized microfluidic devices to find drugs that enhance regeneration and axonal sprouting of motor axons.

Tolerant Mechanism and Chromosome Location of Gene Controlling Sprouting Tolerance in Aegilops Tauschii Cosson

An artificial amphiploid RSP (2n = 42, AABBDD) between tetraploid landrace Ailanmai (Triticum turgidum L., 2n= 28, AABB) and Aegllops tauschii (DD, 2n = 14) expressed high tolerance to preharvest sprouting which derived from Ae. tauschii. Tolerance to preharvest sprouting of RSP was examined by four ways in six varying periods after anthesis. The germination percentages of preharvest intact spikes were only 6.06% in its high peak period of germination. Its tolerance was mainly decided by the seed dormancy. It was showed that the tolerance to sprouting in ' RSP' derived from Ae. tauschii was inherited as a recessive trait which was controlled by one gene, located on chromosome 2D.

Changes in biochemical constituents and induction of early sprouting by triadimefon treatment in white yam(Dioscorea rotundata Poir.) tubers during storage

The ability of triadimefon （TDM）, a triazolic fungicide, to alter the biochemical constituents and thereby minimizing the days required for sprouting in white yam （Dioscorea rotundata Poir.） tubers during storage under （30±2） ℃ in the dark, was studied. TDM at 20 mg/L was given to tubers by dipping the tubers in treatment solution containing 20 mg/L TDM on 10, 25 and 40 d after storage （DAS）. Starch, sugars, protein, amino acid contents as well as protease and a-amylase activities were estimated on 15, 30 and 45 DAS from two physiological regions viz., apical and basal regions of the tubers. In normal conditions （control） sprouting occurred on 70 to 80 DAS. The starch content decreased, while protein, amino acid, sugar contents and protease and a-amylase activities were increased due to TDM treatment and led to early sprouting.

QTL mapping revealed TaVp-1A conferred pre-harvest sprouting resistance in wheat population Yanda 1817×Beinong 6

Pre-harvest sprouting （PHS） occurs frequently in most of the wheat cultivation area worldwide, which severely reduces yield and end-use quality, resulting in substantial economic loss. In this study, quantitative trait loci （QTL） for PHS resistance were mapped using an available high-density single nucleotide polymorphism （SNP） and simple sequence repeat （SSR） genetic linkage map developed from a 269 recombinant inbred lines （RILs） population of Yanda 1817xBeinong 6. Using phenotypic data on two locations （Beijing and Shijiazhuang, China） in two years （2012 and 2013 harvesting seasons）, five QTLs, designated as QPhs.cau-3A. 1, QPhs.cau-3A.2, QPhs.cau-5B, QPhs.cau-4A, and QPhs.cau-6A, for PHS （GP） were detected by inclusive composite interval mapping （ICIM） （LOD≥2.5）. Two major QTLs, QPhs.cau-3A.2 and QPhs.cau-5B, were mapped on 3AL and 5BS chromosome arms, explaining 6.29-21.65% and 4.36-5.94% of the phenotypic variance, respectively. Precise mapping and comparative genomic analysis revealed that the TaVp-1A flanking region on 3AL is responsible for QPhs.cau-3A.2. SNP markers flanking QPhs.cau-3A.2 genomic region were developed and could be used for introgression of PHS tolerance into high yielding wheat varieties through marker-assisted selection （MAS）.

Extrinsic inhibitors in axon sprouting and functional recovery after spinal cord injury

The limited axonal growth after central nervous system （CNS） injury such as spinal cord injury presents a major challenge in promoting repair and recovery. The literature in axonal repair has focused mostly on frank regeneration of injured axons. Here, we argue that sprouting of uninjured axons, an innate repair mech- anism of the CNS, might be more amenable to modulation in order to promote functional repair. Extrinsic inhibitors of axonal growth modulate axon sprouting after injury and may serve as the first group of therapeutic targets to promote functional repair.

Acrylamide inhibits nerve sprouting induced by botulinum toxin type A

Botulinum toxin type A is a potent muscle relaxant that blocks the transmission and release of acetylcholine at the neuromuscular junction. Intramuscular injection of botulinum toxin type A has served as an effective and safe therapy for strabismus and focal dystonia. However, muscular weakness is temporary and after 3-4 months, muscle strength usually recovers because function- al recovery is mediated by nerve sprouting and reconstruction of the neuromuscular junction. Acrylamide may produce neurotoxic substances that cause retrograde necrotizing neuropathy and inhibit nerve sprouting caused by botulinum toxin type A. This study investigated whether acrylamide inhibits nerve sprouting after intramuscular injection of botulinum toxin type A. A tibial nerve sprouting model was established through local injection of botulinum toxin type A into the right gastrocnemius muscle of Sprague-Dawley rats. Following intramuscular injection, rats were given intraperitoneal injection of 3% acrylamide every 3 days for 21 days. Nerve sprout- ing appeared 2 weeks after intramuscular injection of botulinum toxin type A and single-fiber electromyography revealed abnormal conduction at the neuromuscular junction I week after intra- muscular injection of botulinum toxin type A. Following intraperitoneal injection of acrylamide, the peak muscle fiber density decreased. Electromyography jitter value were restored to normal levels 6 weeks after injection. This indicates that the maximal decrease in fiber density and the time at which functional conduction of neuromuscular junction was restored were delayed. Addition- ally, the increase in tibial nerve fibers was reduced. Acrylamide inhibits nerve sprouting caused by botulinum toxin type A and may be used to prolong the clinical dosage of botulinum toxin type A.

Repairing the injured spinal cord: sprouting versus regeneration. Is this a realistic match?

The article by Meves and Zheng （2014） is addressing a continu- ous shift in the field of spinal cord injury （SCI） research that has occurred over the last century. Before that, the spinal cord was viewed as ＂hard wired＂ and treatment considerations were based on observations that axons in the periphery were able to regenerate, but those in the central nervous system （CNS） were not （David and Aguayo, 1981）.

Sprouting Value Index and Viability Percentage： An Integrated Measure of Vegetative Planting Material

Rooting ability of indole 3-butyric acid （IBA）-induced stem cuttings in vegetative regeneration experiments depends on various parameters, which can be entrenched using sprouting value index （SVI）, a mathematical approach. In this study, field studies were carried out in Tabebuia rosea to generate clonal planting stock regeneration using three rooting medium at a location in Central Kerala, Peninsular India, for three consecutive years from October 2014 till June 2016 at four months regular intervals. Three IBA concentrations, viz., 200, 500 and 1,000 ppm, have been used and the data obtained was evaluated using SVI method in order to establish the suitable medium, which gives the maximum rooting results. Control cuttings did not record rooting in any of the trials. The high SVI was obtained when stem root cuttings planted in root trainers with coir pith compost （RTCP） for all the three concentration of IBA applied. Sprouting percentage was marked up and the delay in completion of sprouting/rooting initiation decreased by the use of IBA treatment.

The association between the allelic state of <i>Vp</i>-1<i>B</i>and pre-harvest sprouting tolerance in red-seeded hexaploid triticale

The core collection of red-seeded winter hexaploid triticale with different pre-harvest sprouting (PHS) resistance has been evaluated for the allelic structure of the gene VIVIPAROUS-1B (Vp-1B) with STS molecular marker. The discovered structure of the collection was as follows: 50.0% and 41.7% of the collection carries Vp-1Bа and Vp-1Bc alleles, respectively, while 8,3% possesses both of them. As a result of the seed color estimation, the collection has been divided into two groups: with dark red seeds and light red seeds. The allele Vp-1Bc has appeared to be associated with PHS resistance while Vp-1Ba with PHS susceptibility in the triticale accessions with light red seeds only. The influence of the seed color and allelic state of Vp-1B on PHS resistance in triticale is discussed.

Isolation and Functional Characterization of a B3 Transcription Factor Gene <i>FUSCA3</i>Involved in Pre-Harvest Sprouting Resistance in Wheat

Pre-harvest sprouting (PHS) reduces yields and grain quality, resulting in seriously economic losses in wheat. It has been showed that PHS is significantly correlated to seed dormancy levels. FUSCA3 (FUS3) gene is considered to be the key regulator of seed dormancy. However, little information is available about the function of FUS3 gene (TaFUS3) in wheat. In this study, three homologous genes were identified in wheat grain, and their functions were investigated by gene silencing. Three full-length DNA (3477, 3534 and 3501 bp) and cDNA (1015, 1012 and 1015 bp) sequences encoding a B3 transcription factor, designated TaFUS3-3A, TaFUS3-3B and TaFUS3-3D, were first isolated from common wheat. The transcription of three TaFUS3 genes in seed development and germination process was detected. TaFUS3-3B and TaFUS3-3D had similar expression profiles, and high levels of gene transcripts were detected in seeds at 25 DAP (days after pollination) and after 24 h of imbibition. However, the transcription of TaFUS3-3A was not detected. Silencing of TaFUS3 in common wheat spikes resulted in increased seed germination and PHS. Compared with wild-type, the TaFUS3-silenced plants showed increased expression of genes related to GA biosynthesis and ABA metabolism, and decreased expression of genes associated with ABA biosynthesis. Moreover, silencing of TaFUS3 in wheat plants led to a decrease in embryo sensitivity to ABA and changed the expression of genes involved in ABA signal transduction. The results of gene silencing indicated that TaFUS3 plays a positive role in wheat seed dormancy and PHS-resistance, which might be associated with ABA, GA level and signal transduction.

TaSRO1 interacts with TaVP1 to modulate seed dormancy and pre-harvest sprouting resistance in wheat

Dormancy is an adaptive trait which prevents seeds from germinating under unfavorable environmental conditions.Seeds with weak dormancy undergo pre-harvest sprouting(PHS)which decreases grain yield and quality.Understanding the genetic mechanisms that regulate seed dormancy and resistance to PHS is crucial for ensuring global food security.In this study,we illustrated the function and molecular mechanism of TaSRO1 in the regulation of seed dormancy and PHS resistance by suppressing TaVP1.The tasro1 mutants exhibited strong seed dormancy and enhanced resistance to PHS,whereas the mutants of tavp1 displayed weak dormancy.Genetic evidence has shown that TaVP1 is epistatic to TaSRO1.Biochemical evidence has shown that TaSRO1 interacts with TaVP1 and represses the transcriptional activation of the PHS resistance genes TaPHS1 and TaSdr.Furthermore,TaSRO1 undermines the synergistic activation of TaVP1 and TaABI5 in PHS resistance genes.Finally,we highlight the great potential of tasro1 alleles for breeding elite wheat cultivars that are resistant to PHS.

Netrin-3 Suppresses Diabetic Neuropathic Pain by Gating the Intra-epidermal Sprouting of Sensory

tDiabetic neuropathic pain(DNP)is the most common disabling complication of diabetes.Emerging evi-dence has linked the pathogenesis of DNP to the aberrant sprouting of sensory axons into the epidermal area;however,the underlying molecular events remain poorly understood.Here we found that an axon guidance molecule,Netrin-3(Ntn-3),was expressed in the sensory neurons of mouse dorsal root ganglia(DRGs),and downregulation of Ntn-3 expression was highly correlated with the severity of DNP in a diabetic mouse model.Genetic ablation of Ntn-3 increased the intra-epidermal sprouting of sensory axons and worsened the DNP in diabetic mice.In contrast,the elevation of Ntn-3 levels in DRGs significantly inhibited the intra-epidermal axon sprouting and alleviated DNP in diabetic mice.In con-clusion,our studies identified Ntn-3 as an important regula-tor of DNP pathogenesis by gating the aberrant sprouting of sensory axons,indicating that Ntn-3 is a potential druggable target for DNP treatment.

Polyethylene glycol fusion repair of severed sciatic nerves accelerates recovery of nociceptive sensory perceptions in male and female rats of different strains

Successful polyethylene glycol fusion(PEG-fusion)of severed axons following peripheral nerve injuries for PEG-fused axons has been reported to:(1)rapidly restore electrophysiological continuity;(2)prevent distal Wallerian Degeneration and maintain their myelin sheaths;(3)promote primarily motor,voluntary behavioral recoveries as assessed by the Sciatic Functional Index;and,(4)rapidly produce correct and incorrect connections in many possible combinations that produce rapid and extensive recovery of functional peripheral nervous system/central nervous system connections and reflex(e.g.,toe twitch)or voluntary behaviors.The preceding companion paper describes sensory terminal field reo rganization following PEG-fusion repair of sciatic nerve transections or ablations;howeve r,sensory behavioral recovery has not been explicitly explored following PEG-fusion repair.In the current study,we confirmed the success of PEG-fusion surgeries according to criteria(1-3)above and more extensively investigated whether PEG-fusion enhanced mechanical nociceptive recovery following sciatic transection in male and female outbred Sprague-Dawley and inbred Lewis rats.Mechanical nociceptive responses were assessed by measuring withdrawal thresholds using von Frey filaments on the dorsal and midplantar regions of the hindpaws.Dorsal von Frey filament tests were a more reliable method than plantar von Frey filament tests to assess mechanical nociceptive sensitivity following sciatic nerve transections.Baseline withdrawal thresholds of the sciatic-mediated lateral dorsal region differed significantly across strain but not sex.Withdrawal thresholds did not change significantly from baseline in chronic Unoperated and Sham-operated rats.Following sciatic transection,all rats exhibited severe hyposensitivity to stimuli at the lateral dorsal region of the hindpaw ipsilateral to the injury.However,PEG-fused rats exhibited significantly earlier return to baseline withdrawal thresholds than Negative Control rats.Furthermore,PEG-fused rats with significantly improved Sciatic Functional Index scores at or after 4 weeks postoperatively exhibited yet-earlier von Frey filament recove ry compared with those without Sciatic Functional Index recovery,suggesting a correlation between successful PEG-fusion and both motor-dominant and sensory-dominant behavioral recoveries.This correlation was independent of the sex or strain of the rat.Furthermore,our data showed that the acceleration of von Frey filament sensory recovery to baseline was solely due to the PEG-fused sciatic nerve and not saphenous nerve collateral outgrowths.No chronic hypersensitivity developed in any rat up to 12 weeks.All these data suggest that PEG-fusion repair of transection peripheral nerve injuries co uld have important clinical benefits.

Sdr4 dominates pre-harvest sprouting and facilitates adaptation to local climatic condition in Asian cultivated rice

Pre-harvest sprouting(PHS),which reduces grain yield and quality,is controlled by seed dormancy genes.Because few dormancy-related genes have been cloned,the genetic basis of seed dormancy in rice(Oryza sativa L.)remains unclear.Here,we performed a genome-wide association study and linkage mapping to dissect the genetic basis of seed dormancy in rice.Our findings suggest that Seed Dormancy4(Sdr4),a central modulator of seed dormancy,integrates the abscisic acid and gibberellic acid signaling pathways at the transcriptional level.Haplotype analysis revealed that three Sdr4 alleles in rice cultivars already existed in ancestral Oryza rufipogon accessions.Furthermore,like the semi-dwarf 1(SD1)and Rc loci,Sdr4 underwent selection during the domestication and improvement of Asian cultivated rice.The distribution frequency of the Sdr4-n allele in different locations in Asia is negatively associated with local annual temperature and precipitation.Finally,we developed functional molecular markers for Sdr4,SD1,and Rc for use in molecular breeding.Our results provide clues about the molecular basis of Sdr4-regulated seed dormancy.Moreover,these findings provide guidance for utilizing the favorable alleles of Sdr4 and Rc to synergistically boost PHS resistance,yield,and quality in modern rice varieties.