Pectin methylesterase inhibitors GhPMEI53 and AtPMEI19 improve seed germination by modulating cell wall plasticity in cotton and Arabidopsis

The germination process of seeds is influenced by the interplay between two opposing factors,pectin methylesterase(PME)and pectin methylesterase inhibitor(PMEI),which collectively regulate patterns of pectin methylesterification.Despite the recognized importance of pectin methylesterification in seed germination,the specific mechanisms that govern this process remain unclear.In this study,we demonstrated that the overexpression of GhPMEI53is associated with a decrease in PME activity and an increase in pectin methylesterification.This leads to seed cell wall softening,which positively regulates cotton seed germination.AtPMEI19,the homologue in Arabidopsis thaliana,plays a similar role in seed germination to GhPMEI53,indicating a conserved function and mechanism of PMEI in seed germination regulation.Further studies revealed that GhPMEI53 and AtPMEI19 directly contribute to promoting radicle protrusion and seed germination by inducing cell wall softening and reducing mechanical strength.Additionally,the pathways of abscicic acid(ABA)and gibberellin(GA)in the transgenic materials showed significant changes,suggesting that GhPMEI53/AtPMEI19-mediated pectin methylesterification serves as a regulatory signal for the related phytohormones involved in seed germination.In summary,GhPMEI53 and its homologs alter the mechanical properties of cell walls,which influence the mechanical resistance of the endosperm or testa.Moreover,they impact cellular phytohormone pathways(e.g.,ABA and GA)to regulate seed germination.These findings enhance our understanding of pectin methylesterification in cellular morphological dynamics and signaling transduction,and contribute to a more comprehensive understanding of the PME/PMEI gene superfamily in plants.

Arginine promotes seed energy metabolism,increasing wheat seed germination at low temperature

Low temperatures during germination inhibit seed growth,lead to small and weak seedlings,and significantly reduce the wheat yield.Alleviating the adverse effects of low temperature on wheat seed germination is highly important for achieving high and stable wheat yields.In this study,Tongmai 6(insensitive)and Zhengmai 113(sensitive),which have different low-temperature sensitivities during germination were treated with low temperature during germination.The transcriptome,metabolome and physiological data revealed that low temperature decreased the germination rate,downregulated the expression of a large number of genes involved in regulating glycometabolism,and inhibited carbon,nitrogen(especially amino acids)and energy metabolism in the seeds.Arginine content increased at low temperature,and its increase in the low-temperature-tolerant variety was significantly greater than that in the sensitive variety.Arginine priming experiment showed that treatment with an appropriate concentration of arginine improved the seed germination rate.The conversion of starch to soluble sugar significantly increased under exogenous arginine conditions,the content of key metabolites in energy metabolism increased,and the utilization of ATP in the seeds increased.Taken together,arginine priming increased seed germination at low temperature by relieving inhibition of seed carbon and nitrogen metabolism and improving seed energy metabolism.

Genome-wide association study reveals that JASMONATE ZIM-DOMAIN 5 regulates seed germination in rice

Seed germination is a complex trait regulated by multiple genes in rice.However,the regulators of rice seed germination have yet to be sufficiently determined.Here,a quantitative trait locus(QTL)for rice seed germination was identified in a genome-wide association study.The candidate gene JASMONATE ZIM-DOMAIN 5(OsJAZ5)of the QTL was verified that positively regulates seed germination.OsJAZ5 regulation of seed germination involves an OsABI3-mediated abscisic acid pathway.Overexpression of OsJAZ5 facilitated seed germination.The application of OsJAZ5 might be useful for increasing seed germination for rice direct seeding.

Preparation of Tartary Buckwheat Seed Coating Agent and Its Effect on Germination

To mitigate the wastage of seed resources and reduce the usage of pesticides and fertilizers, seed coating agentshave gained popularity. This study employs single-factor and multi-index orthogonal experimental design methodsto investigate the seed coating formula and physical properties of Tartary buckwheat. The specific effects ofeach component on Tartary buckwheat seed germination are analyzed. The findings reveal that the seed coatingagent formulated with 1.5% polyvinyl alcohol, 0.15% sodium alginate, 0.2% op-10, 0.1% polyacrylamide, 8% colorant,3% ammonium sulfate, 1% potassium dihydrogen phosphate, and 0.15% carbendazim exhibits the mosteffective coating. It demonstrates optimal physical properties and promotes seed germination efficiently. The suspensionrate of this seed coating agent reaches 91.12%, with a mere 2.13% coating shedding rate and 2.5% coatingseed rot rate. Furthermore, it achieves a germination percentage of 99.17%, which is 20.84% higher than the lowestgroup. The germination potential and index are also significantly higher than the lowest group, with anincrease of 20.84% and 26.56%, respectively. Additionally, the vitality index is 553.08, a 15.75% increase comparedto the lowest group. The application of seed coating agents helps reduce seed resource loss, increase plant numbers,and ultimately enhance agricultural yields. This finding holds practical significance in agriculturalproduction.

Effects of Low Temperature Stress on Germination and Physiological Characteristics of Different Sweet Maize Varieties

[Objectives]The paper was to explore the effects of low temperature stress on germination and physiological characteristics of different sweet maize varieties.[Methods]Taking Taitian 264,Zhexuetian 1 and Chaotian 4 as the research objects,the changes in germination potential,germination index,plant height,biomass,and antioxidant enzyme activity of maize seeds were studied under optimal temperature conditions(25℃)and low temperature stress conditions(10℃).[Results]Under 10℃stress,the germination rate and germination index of Taitian 264 were higher than that of Zhexuetian 1 and Chaotian 4.Under low temperature stress,Taitian 264 exhibited the least reduction in height and biomass,while Zhexuetian 1 had the most reduction.Additionally,the SOD and POD activities of Taitian 264 were higher than that of Zhexuetian 1 and Chaotian 4 under both temperature conditions,while the MDA content of Taitian 264 was lower.Taitian 264 showed strong germination ability against low temperature stress.[Conclusions]This study provides a basis for timely sowing practices of sweet maize in agricultural production.

Effect of cold stratification on the temperature range for germination of Pinus koraiensis

Germination at low spring temperatures may offer a competitive advantage for the growth and survival of plant species inhabiting temperate forest ecosystems.Pinus koraiensis is a dominant species in temperate forests of northeastern China.Its seeds exhibit primary morphophysiological dormancy following dispersal in autumn,limiting natural or artificial regeneration:direct seeding and planting seedlings in spring.The aim of this study was to determine the optimum cold stratification temperature that induces germination to increase towards lower temperatures.Seeds from two populations(Changbaishan and Liangshui)were cold stratified at 0,5 and 10℃.Germination to incubation temperatures(10/5,20/10,25/15 and 30/20℃;14/10 h day/night)were determined after 2 and 4 weeks,and 5.5 and6.5 months of cold stratification.After 5.5 months,approximately 68-91%of seeds from both populations germinated at incubation temperatures of 25/15℃and 30/20℃,regardless of cold stratification temperatures.When the cold stratification temperature was reduced to 0℃and the period increased to 6.5 months,germination at 10/5℃significantly improved,reaching 37%and 64%for the Changbaishan and Liangshui populations,respectively.After 6.5 months of cold stratification,there was a significant linear regression between cold stratification temperatures and germination at10/5℃.The range in temperatures allowing for germination gradually expanded to include lower temperatures with decreasing cold stratification temperatures from 10 to 5℃and further to 0℃.

Germination Quality Prognosis: Classifying Spectroscopic Images of the Seed Samples

One of the most critical objectives of precision farming is to assess the germination quality of seeds.Modern models contribute to thisfield primarily through the use of artificial intelligence techniques such as machine learning,which present difficulties in feature extraction and optimization,which are critical factors in predicting accuracy with few false alarms,and another significant dif-ficulty is assessing germination quality.Additionally,the majority of these contri-butions make use of benchmark classification methods that are either inept or too complex to train with the supplied features.This manuscript addressed these issues by introducing a novel ensemble classification strategy dubbed“Assessing Germination Quality of Seed Samples(AGQSS)by Adaptive Boosting Ensemble Classification”that learns from quantitative phase features as well as universal features in greyscale spectroscopic images.The experimental inquiry illustrates the significance of the proposed model,which outperformed the currently avail-able models when performance analysis was performed.

Effects of polyamines on the early development of cystocarps,spore release,survival,and germination rate of Gracilariopsis lemaneiformis

Three polyamines(PAs)(spermidine(Spd),spermine(Spm),and putrescine(Put))were used as growth regulators to the marine macroalgae Gracilariopsis lemaneiformis and to female gametophyte and reproductive tissues(cystocarps were constructed),which led to early maturation of cystocarps and spore release.Laboratory cultivation revealed that exogenous PA application accelerated the development of cystocarps,and the mean sporeling growth rate was 20%–50%/d during the initial week of cultivation.The spore count(SC),survival rate(SR),and germination rate(GR)of G.lemaneiformis showed different responses to PA(10-6 mol/L and 10-3 mol/L)treatments under different temperatures(18,26,and 34℃),light intensities(30,60,and 90μmol photons/(m^(2)·s)),salinities(25,30,and 35),and nutrient levels(25꞉2.5,50꞉5.0,and 75꞉7.5μmol/L NH4Cl꞉K2HPO4),and the optimal conditions were 26℃,light intensity of 60μmol/(m^(2)·s),salinity of 35,and nutrient level of 50꞉5.0μmol/L NH4Cl꞉K2HPO4.Under the optimum conditions,the SC per cystocarp increased by 82.38%,and the spore SR and GR increased by 33.07%and 46.44%,respectively.Each experiment lasted for 7 days,with the highest SC on Day 4 and plateauing on Day 7.The results indicate that PAs could promote the early maturation,spore release,survival,and germination of G.lemaneiformis under laboratory conditions.

Seed Priming Improves Enzymatic and Biochemical Performances of Rice During Seed Germination under Low and High Temperatures

As an abiotic stress,adverse germination temperatures cause serious disruptions in physiological and biochemical processes involved in seed germination.Using a factorial experiment,we examined the effects of different seed priming treatments on enzymatic and biochemical performances of rice seed germination under different temperatures.Each of the rice genotypes(Hashemi,Sadry-domsefid,IRON-70-7053-7 and NORIN-22)was primed with hydro-hardening,KCl,CaCl2 and ascorbic acid(AsA)and without a priming agent as a control at low(15℃),optimum(25℃)and high(35℃)germination temperatures.The results showed that the enzymatic and biochemical performances of all the rice genotypes were affected by the seed priming agents,especially under the low germination temperature.At 15℃,seed priming with AsA was found to be the best agent for the activities of amylase,α-amylase,catalase(CAT),peroxidase(POX),ascorbate peroxidase(APOX)and superoxide dismutase(SOD)as well as the content of soluble sugars in the NORIN-22 genotype,and for protease activity and soluble protein content in the IRON-70-7053-7 genotype.SOD at the low germination temperature and CAT,POX and protease at the optimum and high germination temperatures were the most important enzymes in occurrence of germination potential in terms of seedling length,vigor index,normal seedling rate and germination rate.Under the priming agents,the highest changes in normal seedling rate were observed at the low and optimum germination temperatures by AsA priming in the Hashemi and NORIN-22 genotypes,and at the high germination temperature under KCl priming in the Hashemi genotype.

Responses of maize germination,root morphology and leaf trait to characteristics of lead pollution:a case study

On base of the content of Pb in the soil under different land use patterns in Lanping Lead-zinc mining area,Yunnan in southwest China,the root morphology and leaf traits of maize in different concentration Pb(20,40,60,80,100,150,200,500,1000,2000,3000 mg/L)were analyzed.The results showed that maize germination rate,germination vigor and growth index decreased with the increase of Pb concentration.The root length,surface area of maize increased by 0.21%-81.58%,8.99%-73.43%,1.50%-77.37%,respectively,under 20-500 mg/L Pb concentration.However,these parameters under 1000-3000 mg/L Pb concentration decreased by 37.86%-553.54%,44.99%-766.16%,55.99%-92.81%,respectively,and these lowest value appeared in 3000 mg/L Pb treatment.The root volume of maize increased by 4.57%-89.25%in 20-80 mg/L Pb concentration,and it decreased with the increase of Pb concentration when the Pb concentration was higher than 80 mg/L and decreased by 94.13%in 3000 mg/L Pb.The root surface area and length of 0.50-1.00 diameter class were higher than those of other diameter classes,and these value of maize under 500 mg/L Pb were higher than those of other concentrations.The length and perimeter of maize leaves with the highest value of 220.36 and 962.68 mm,respectively appeared in 60 mg/L Pb treatment.The leaf width and area of maize with the highest value of 15.68 mm and 2448.31 mm^(2),respectively,appeared in 40 mg/L Pb treatment,which indicated that the leaf traits of maize were promoted by low concentration Pb and inhibited by high concentration Pb.

Impact of ZnSO_(4)^(-)and ZnO Nanoparticles on Seed Germination and Seedling Growth of Lettuce

Micronutrient nanoparticles(NPs)are currently an option for chemical fertilization and biostimulation in crops.However,there is little information on the phytotoxic or biostimulatory effects of NPs at low concentrations of some elements,such as Zn.In this study,the effect of low concentrations of Zn oxide(ZnO)NPs on germination,growth variables,and nutritional attributes of lettuce(Lactuca sativa L.)was evaluated in comparison to Zn sulfate.Romaine lettuce seeds were treated with ZnSO_(4)^(-)×7H_(2)O and ZnO NPs at Zn molar concentrations of 1×10^(−3),5×10^(−3),1×10^(−4),5×10^(−4),1×10^(−5),5×10^(−5),1×10^(−6),and 5×10^(−6).The seeds treated with ZnSO4−at 5×10^(−6)registered the highest radicle length,73%more than the control treatment.The seeds treated with ZnSO4−at 5×10^(−3)registered the lowest values,with 50%less than the control treatment.ZnO NPs at 5×10^(−6)significantly increased content of chlorophyll A and B and total phenolics.These results indicate the possible existence of a mechanism related to the intrinsic nanoparticle properties,especially at low concentrations.

Substrate,Hormone,Winnowing,and Stratification Influence the Seed Germination of Ilex asprella(Hook.et Arn.)Champ.ex Benth

Ilex asprella(Hook.et Arn.)Champ.ex Benth is one of the most important traditional Chinese medicines in southern China.The seeds of Ilex asprella usually have extremely low germination due to their dormancy characteristics,which severely impacts the efficiency of seedling raising and increases labor costs.In this study,to improve the seed germination of I.asprella,the effects of germination substrate,hormone,winnowing,and stratification treatments on the seed germination of I.asprella were investigated.The results of the germination matrix showed that the highest germination percentage of 45.2%was achieved under the 20℃/10℃day/night temperature and vermiculite germination medium conditions.The results of hormone treatments revealed that 100–400 mg/L of gibberellin(GA)and 50–100 mg/L of salicylic acid(SA)were found to be effective in releasing the dormancy of I.asprella seeds.Moreover,winnowing could effectively eliminate unsaturated seeds and impurities,thus improving the seed germination of I.asprella.Furthermore,warm temperature(15℃)stratification could expand the temperature range of I.asprella’s seed germination,which was beneficial for seed germination of I.asprella and for seed nursery at room temperature in production practice.The present study obtained a method to break dormancy and increase seed germination in I.asprella,thereby forming a groundwork for improving the efficiency of large-scale planting of I.asprella.

In vitro Evaluation of Seed Germination in Twelve Alfalfa Cultivars under Salt Stress

Alfalfa(Medicago sativa L.),when exposed to abiotic stress such as salinity,suffers significant losses in yield and productivity.The present study evaluated the salinity tolerance of 12 alfalfa cultivars in vitro using five concentrations of sodium chloride(NaCl),ranging from 0 to 250 mmol L^(−1).The results obtained in the current study revealed that the Saudi cultivars,Kasimi and Hassawi,and the German cultivar(Berlin)had the highest salinity tolerance in terms of germination percentage(GP),corrected germination rate index(CGRI),days to reach 50%germination(GT_(50)),and ability to form cotyledonary and true leaves.Under mmol L^(−1) NaCl,the Saudi cultivar Kasimi cultivar showed GP,CGRI,and GT_(50) of 55.20%,123.15,and 3.77 days,respectively.Similarly,the German cultivar(Berlin)showed GP,CGRI,and GT_(50) of 50.06%,86.61,and 5.17 days,respectively.These findings might reveal a pivotal aspect in salt tolerance in alfalfa.Our results will help to select salt-tolerant alfalfa cultivars that could thrive in arid and semi-arid areas with salinity problems.

Melatonin Promotes Rice Seed Germination under Drought Stress by Regulating Antioxidant Capacity

Drought stress is a serious threat to the germination of plant seeds and the growth of seedlings.Melatonin has been proven to play an important role in alleviating plant stress.However,its effect on seed germination under drought conditions is still poorly understood.Therefore,we studied the effects of melatonin on rice seed germination and physiological characteristics under drought stress.Rice seeds were treated with different concentrations of melatonin(i.e.,0,20,100,and 500μM)and drought stress was simulated with 5%polyethylene glycol 6000(PEG6000).The results showed that 100μM melatonin can effectively improve the germination potential,rate and index;the vigor index of rice seeds;and the length of the shoot and root.In addition,that treatment also increased the activity of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT),and reduced the content of malondialdehyde(MDA).The grey relational grade between the shoot MDA content and the melatonin seed-soaking treatment was the highest,which could be useful for evaluating the effect of melatonin on drought tolerance.Two-way analysis of variance showed that the effect of single melatonin treatment on rice seeds was more significant than that of single drought stress and interaction treatment of drought and melatonin(p<0.05).The subordinate function results showed that 100μM melatonin significantly improved the germination and physiological indexes of rice seeds and effectively alleviated the adverse effects of drought stress on rice seedlings.The results helped to improve the understanding of the morphological and physiological involvement of melatonin in promoting seed germination and seedling development under drought stress.

Comparative Transcriptome Analysis of Seed Germination of a Cotton Variety with High Tolerance to Low Temperature

Gossypium hirsutum L.is an important cash crop native to the subtropics and is widely cultivated around the world.Low temperature is an important stress that seriously affects seed germination and emergence during planting.In this study,transcriptomic profiles of low-temperature-and normal-temperature-germinated seeds of Xinluzao 25,a variety with low-temperature tolerance and high germination rates,were analyzed and compared.The following results were obtained.(1)A total of 81.06 Gb of clean data were obtained after transcriptome sequencing and assembly,and 76,931 non-redundant Unigene sequences were obtained after data consolidation and concatenation;of these,69,883 Unigene sequences were annotated.In addition,55,463 Unigene transcript sequences(72.2%)were annotated for Gene Ontology(GO)classification,and 26,629 genes were involved in 50 metabolic pathways identified by Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis.(2)Three main pathways related to low-temperature tolerance of seed germination were identified:starch and sucrose metabolism,phenylpropanoid biosynthesis,and cysteine and methionine metabolism.Their main molecular functions involve the regulation of abscisic acid and activities of enzymes such as amylase,peroxidase,and oxidoreductase.During germination at low temperature,more genes were down-regulated than up-regulated genes at the protrusion stage(2 mm),and more genes were up-regulated than down-regulated at the germination stage(30 mm)after protrusion.(3)The enzyme activities at the two stages showed that amylase,peroxidase,catalase,and glutathione reductase had higher activities when the seeds germinated at 15℃.In this study,high expression of amylase,peroxidase,catalase,and glutathione reductase genes may be the main cause of increased tolerance to low temperature.

Seed Germination and Vegetative Propagation of Promising Decorative Lonicera tatarica L. (Caprifoliaceae Juss.), Introduced into the Tashkent Botanical Garden (Uzbekistan)

Seed germination (in laboratory and field conditions) and vegetative reproduction (by cuttings) of a promising decorative species—Lonicera tatarica L. (Caprifoliaceae Juss.) was studied for the first time in the conditions of introduction of the Tashkent Botanical Garden of Uzbekistan. Thus, the optimal temperature for germination of L. tatarica seeds in laboratory conditions is +20°C + 22°C, at which germination was 73%. The germination rate of seeds sown in autumn in the field was 62%, and the germination rate of seeds sown in spring was 71%. It was noted that in greenhouse conditions at an air temperature of 20°C - 22°C and a relative humidity of 49% - 53%, the rootability of cuttings was 75%. It was revealed that the studied species adapted well to the conditions of introduction. Taking into account the effectiveness of vegetative reproduction of L. tatarica, it can be recommended for improving the aesthetic condition and landscaping of cities, landscaping and landscape design.

Study of the Germination of Scarified Seeds of Burkea africana Hook. For Its Domestication in Chad

The objective of this work was to determine new approaches that could improve the germination quality of Burkea africana seeds under reproducible conditions and by means available to farmers with a view to its propagation. The tests concerned the influence of three pre-germinative treatments. It is about the light scarification (Scl), medium scarification (Scm) and deep scarification (Scd) of seeds in order to determine some parameters of germination that are the latency time, the time of germination, the rate of germination and the speed of germination. The treated seeds were sown in transparent germinators lined with hydrophilic paper and then after the appearance of radicles, the plants were transplanted on five types of substrates (black soil, fine sand, sawdust, mixtures 1/1 of sawdust-black soil and 1/1 of sawdust-fine sand). The results obtained by the deep (Scp) and medium (Scm) scarification compared to those of the light scarification and the control, showed a clear reduction of the lag time (3 days/15 days (control). At the 5% threshold, germination times 6.27 × 10-1 (Scd) and 6.01 × 10-1 (Scm) were significantly influenced. Germination rates 4.18 × 10-1 (Scd) and 3.92 × 10-1 (Scm) are also influenced by the pretreatment. Germination rates are significantly improved (80%). Regardless of the under treatment, the substrate “sawdust and fine sand” improves the germination of scarified seeds by 14.07% more compared to the substrate “fine sand” at the 5% threshold. The mechanical scarification and the type of substrates thus influence positively and homogeneously the germination of seeds of Burkea africana. The domestication of this species is thus possible and can be considered for useful purposes.

Effect of Exogenous Gibberellin on Wheat Seed Germination under Salt Stress

[Objectives]In this experiment,wheat seeds were treated with different concentrations of gibberellin and different concentrations of salt solution to study the change of germination index of wheat seeds.[Methods]The germination rate,germination potential and germination index of wheat seeds were measured by routine methods,and the effect of exogenous gibberellin on germination of wheat seeds under salt stress was observed.[Results]The germination rate,germination potential and germination index of wheat seeds under salt stress were significantly increased after exogenous treatment of 0.25 and 0.50 g/L gibberellin within the range of salt concentration gradient.However,when the concentration of gibberellin was too high,it would inhibit the germination of seeds.[Conclusions]Appropriate concentration of gibberellin can effectively alleviate the stress caused by salt on wheat seed germination.In this experiment,the best concentration of gibberellin to alleviate salt stress was 0.25 g/L.

Preliminary Study on in Vitro Germination of Yangmei Pollen

[Objectives]To explore the conditions for in vitro culture of Yangmei pollen.[Methods]Experiments were conducted on the germination characteristics of three types of Yangmei pollen using in vitro culture and germination method.[Results]The suitable medium ratio for the germination of Yangmei pollen was 10%sucrose+0.01%borax+1%agar;the cultivation temperature of 30℃was more suitable for the germination of Yangmei pollen than 25℃;through analysis of variance,among the three types of Yangmei pollen,pollen of male 1 had the strongest viability,and it was the better pollination type.[Conclusions]The research could provide certain basis for introduction and cultivation of Yangmei and improving hybrid breeding effect.

Effect of Pre-Sowing Treatments on Mamalis (Pittosporum pentandrum Blanco Merr.) Seeds Germination under Nursery Condition

Seeds were subjected to three different pre-sowing seed treatments: immersion in lukewarm water for 2 hours, immersion in concentrated sulfuric acid (H2SO4) for 5 minutes, hilar removal, and a control in which the seeds were sown without being treated. The experiment was laid out in the Completely Randomized Design (CRD) with four replicates and 60 seeds per treatment. Seeds were sown in an improvised Seedbox in October 2019. Germination was monitored daily for one month. The results showed that Mamalis seeds treated with lukewarm water have the earliest germination of twelve days, with a germination percentage of 66.67%. The germination rate of another treatment ranges from 0 - 44 percent, compared to 45 percent for the control treatment. It seems prudent to conclude that to enhance the vegetative propagation methods is to soaking in warm water at 37.5˚C for 2 hours could provide the best growth.