Research Progress on the Growth-Promoting Effect of Plant Biostimulants on Crops

A Plant Biostimulant is any substance or microorganism applied to plants to enhance nutrition efficiency,abioticstress tolerance,and/or crop quality traits,regardless of its nutrient content.The application of Plant biostimulants(PBs)in production can reduce the application of traditional pesticides and chemical fertilizers and improvethe quality and yield of crops,which is conducive to the sustainable development of agriculture.An in-depthunderstanding of the mechanism and effect of various PBs is very important for how to apply PBs reasonablyand effectively in the practice of crop production.This paper summarizes the main classification of PBs;Thegrowth promotion mechanism of PBs was analyzed from four aspects:improving soil physical and chemical properties,enhancing crop nutrient absorption capacity,photosynthesis capacity,and abiotic stress tolerance;At thesame time,the effects of PBs application on seed germination,seedling vigor,crop yield,and quality were summarized;Finally,how to continue to explore and study the use and mechanism of PBs in the future is analyzedand prospected,to better guide the application of PBs in crop production in the future.

Endophytic Bacteria Promote the Growth of Suaeda glauca in Saline-Alkali Stress:Regulation of Osmotic Pressure and Antioxidative Defense System

Endophytic bacteria are promising bacterial fertilizers to improve plant growth under adverse environment.For ecological remediation of coastal wetlands,it was necessary to investigate the effect and interaction of endophytes on halophytes under saline-alkali stress.In this study,an endophytic bacterium strain HK1 isolated from halophytes was selected to infect Suaeda glauca under pH(7 and 8)and salinity gradient(150,300 and 450mmolL^(-1)).Strain HK1 was identified as Pantoea ananatis and it had ability to fix nitrogen,dissolve inorganic phosphorus and produce indole-3-aceticacid(IAA).The results showed that strain HK1 could promote the growth of S.glauca seedings when the salinity was less than 300mmolL^(-1),in view of longer shoot length and heavier fresh weight.The infected plants could produce more proline to decrease the permeability of cells,which content increased by 26.2%–61.1%compared to the non-infected group.Moreover,the oxidative stress of infected plants was relieved with the malondialdehyde(MDA)content decreased by 16.8%–32.9%,and the peroxidase(POD)activity and catalase(CAT)activity increased by 100%–500%and 6.2%–71.4%,respectively.Statistical analysis revealed that increasing proline content and enhancing CAT and POD activities were the main pathways to alleviate saline-alkali stress by strain HK1 infection,and the latter might be more important.This study illustrated that endophytic bacteria could promote the growth of halophytes by regulation of osmotic substances and strengthening antioxidant activities.This finding would be helpful for the bioremediation of coastal soil.

Cloning and Functional Analysis of the Porcine Growth Hormone Gene Promoter

[Objective] This study aimed to clone the porcine growth hormone gene promoter and determine the core promoter sequences and the cis-acting elements. [Method] Sequence of the 5＇flanking region of porcine growth hormone gene was searched out and downloaded from the NCBI website. According to the targeted se- quence, primers were designed and synthesized for the PCR amplification. The 1 882 bp （-1 821 bp-＋61 bp） fragment was amplified by PCR. Nine promoter frag- ments with different lengths were obtained by genome-walking deletion method and then cloned into luciferase reporter vectors. Relative transcriptional activities of these 5＇ terminal-deleted plasmids in pituitary and non-pituitary cells were determined by transient transfection of the rat pituitary adenoma cell （GH3）, porcine lilac endotheli- um cell （PIEC） and porcrne Kidney-15 （PK15） with the constructed dual-luciferase vectors. [Result] Result of DNA sequencing showed that the 1 882 bp fragment of GH 5＇ promoter was successfully cloned. Nine luciferase reporter gene plasmids were constructed. DuaI-Luciferase reporter assay indicated that the promoter inserted into reporter gene vector had very strong cell specificity. [Conclusion] Porcine growth hormone gene specifically expresses in pituitary cells. The minimal promoter of the porcine growth hormone gene is mapped at the region -110 bp-＋61 bp. Promoter regions 218 bp--110 bp and -429 bp--218 bp contain positive regulatory elements.

Promoter polymorphism of transforming growth factor-β1 gene and ulcerative colitis

AIM: To elucidate the possible difference in two promoter polymorphisms of the transforming growth factor-β1 (TGF-β1) gene (-800G > A, -509C > T) between ulcerative colitis (UC) patients and normal subjects.METHODS: A total of 155 patients with established ulcerative colitis and 139 normal subjects were selected as controls. Two single nucleotide polymorphisms within the promoter region of TGF-β1 gene (-509C > T and -800G > A) were genotyped using PCR-RFLP. RESULTS: There was a statistically significant difference in genotype and allele frequency distributions between UC patients and controls for the -800G > A polymorphism of the TGF-β1 gene (P < 0.05). The frequency of the TGF-β1 gene polymorphism at position -800 showed that the AA genotype and the allele A frequencies significantly differed between the patients and healthy controls (P < 0.05). At position -509, there was no statically significant difference in genotype and allele frequency between the patients and control subjects.CONCLUSION: The results of our study indicate that there is a significant difference in both allele and genotype frequency at position -800G > A of TGF-β1 gene promoter between Iranian patients with UC and normal subjects.

Biotransformation of Shrimp Wastes by Bacillus subtilis OKF04 and Evaluation of Growth Promoting Effect in Crop Planting

In this study,we proposed a reliable and sustainable technique for the clean utilization of shrimp wastes,which can yield a solid inoculant of Bacillus subtilis OKF04 containing micronutrients at low cost without the risk of contamination.Study of the culture conditions revealed that the head of shrimp Litopenaus vannamei and the wheat bran acted as suitable substrates for the growth of B.subtilis OKF04.With 60%initial moisture content,30℃culture temperature,and 5%inoculation amount,followed by 48 hours of fermentation and 0.5%soluble starch added during the drying process(50℃for 6h),a solid B.subtilis OKF04 inoculant with a spore amount of 2.4×10^(10)CFU g^(-1)and a high amino acid content was obtained.The solid B.subtilis OKF04 inoculant was applied to cultivate pakchoi under pot experiment.As the result,of adding to,the size of stems and leaves,nutritional composition,and physiological activity of pakchoi were significantly(P<0.05)enhanced by solid B.subtilis OKF04 inoculant.B.subtilis OKF04 also significantly(P<0.05)increased the soil’s nutrient content and improved its microbial composition.Furthermore,pakchoi cultivated with a low dose of solid B.subtilis OKF04 inoculant(0.05 g kg^(-1)soil)resulted in the best results.This study provides a new method for the preparation of microbial inoculants with solid waste shrimp heads.

A novel apidaecin Api-PR19 synergizes with the gut microbial community to maintain intestinal health and promote growth performance of broilers

Background: Antibiotic growth promoters(AGPs) have been used as growth promoters to maintain animal intestinal health and improve feed efficiency in broilers by inhibiting pathogen proliferation. In view of the growing emergence of antibiotic-resistant pathogen strains and drug residue issues, novel treatments are increasingly required. This study aimed to compare two antimicrobial approaches for managing pathogen infection and maintaining animal intestinal health in broilers by supplying Apidaecin Api-PR19 and AGPs over 42 d of a feeding trial.Results: Compared with the broilers that were only fed a corn-soybean basal diet(CON group), supplementation with Api-PR19 and AGP(respectively named the ABP and AGP groups) both increased the feed conversion efficiency. When compared with the AGP group, Api-PR19 supplementation could significantly increase the organ index of the bursa of fabricius and subtype H9 antibody level in broiler chickens. Moreover, when compared with the CON group, the intestinal villus height, intestinal nutrient transport, and intestinal s Ig A content were all increased in the Api-PR19 group, while AGP supplementation was harmful to the intestinal villus height and intestinal nutrient transport. By assessing the antibacterial effect of Api-PR19 and antibiotics in vitro and in vivo, we found that Api-PR19 and antibiotics both inhibited the growth of pathogens, including Escherichia coli and Campylobacter jejuni. Furthermore, by using 16 S r RNA gene sequencing, the beneficial bacteria and microbiota in broilers were not disturbed but improved by apidaecin Api-PR19, including the genera of Eubacterium and Christensenella and the species of uncultured_Eubacterium_sp, Clostridium_asparagiforme, and uncultured_Christensenella_sp, which were positively related to improved intestinal development, absorption, and immune function.Conclusion: Apidaecin Api-PR19 treatment could combat pathogen infection and had little negative impact on beneficial bacteria in the gut compared to antibiotic treatment, subsequently improving intestinal development,absorption, and immune function.

Semaphorin 3A: from growth cone repellent to promoter of neuronal regeneration

Highlight Semaphorin 3A is a classically known axonal guidance cue that mediates axonal growth cone repulsion and collapse.Recent works,however,suggest that it may have the apparently diametrically opposite activity of promoting neuronal regeneration.

Utilizing the γ-Irradiated Sodium Alginate as a Plant Growth Promoter for Enhancing the Growth,Physiological Activities,and Alkaloids Production in Catharanthus roseus L.

Sodium alginate is a polysaccharide that is largely obtained from the brown algae （Sargassum sp.）.It has been used as a wonderful growth promoting substance in its depolymerized form for various plants.The aim of this study was to find out the effects of various concentrations of γ-irradiated sodium alginate （ISA）,viz.,deionized water （control,T0）,20 （T1）,40 （T2）,60 （T3）,80 （T4）,and 100 ppm （T5） on the agricultural performance of Catharanthus roseus L.（Rosea） in terms of growth attributes,photosynthesis,physiological activities,and alkaloid production.The present work revealed that ISA applied as leaf-sprays at concentrations from 20 to 100 ppm might improve growth,photosynthesis,physiological activities,and alkaloid production in C.roseus L.significantly.Of the various ISA concentrations,80 ppm proved to be the best one compared to other concentrations applied.

Water Soluble Propolis and Royal Jelly Enhance the Antimicrobial Activity of Honeys and Promote the Growth of Human Macrophage Cell Line

Due to the overuse and misuse of antibiotic, an increase in antibiotic resistance of pathogenic bacteria is evolving. Attention should be focused on natural alternatives to antibiotics, like propolis, royal jelly （R J） and honeys. They all have strong antibacterial properties due to the active substances they contain. This study investigated the effect of combination of water soluble propolis （WSP） Greitl20 or fresh royal jelly （F-RJ） （MiZigoj） and Forest honeys as antibacterial against Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Acinetobacter baumanii, Staphylococcus aureus, methicillin resistant Staphylococcus aureus （MRSA）, Streptococcus pyogenes, Streptococcus agalactiae and Candida albicans. These substances are also cell growth promoters for human macrophage （TLT） cell line. WSP Greitl20, F-RJ （M） and different Forest honeys were prepared in saline as 10% solutions. The antimicrobial activity was expressed as the minimal inhibitory concentration （MIC） in mg/mL. The growth promotion activity was measured at optical density （OD） 595 nm. The combination ofWSP Greitl20 with different Forest honeys is better than F-RJ （M） in same combination with different Forest honeys. The best antibacterial/antifungal activity was found with the combination of 10% WSP Greit 120 in the Forest honey （1：10） from Italy or Spain. When measuring the growth promoting activity of TLT cell line, the best activity was detected at the combination of 10% WSP Greitl20 in the Forest honey from Italy （GI3 = 0.796 ± 0.014 and GI5 = 1.133± 0.022）. Antimicrobial and growth promoting activities are correlated and WSP-dependent.

Analysis of SNPs in the Promoter Region of the Growth Hormone(GH) Gene in Mini-pigs

Single nucleotide polymorphisms(SNPs) of the growth hormone(GH) gene were investigated in six pig breeds,consisting of four mini-pig breeds(Wuzhishan,Bama,Xiang and Tibet pig),and two others(Dahlan and Landrace pig).Three pairs of primers for promoter regions of the GH gene were designed on the basis of the pig genomic sequence and SNPs were detected by the PCR-SSCP method.The results indicated three mutations in the 5’-flanking region.The analysis results showed that the frequencies of allele A and D in four mini-pig breeds were higher than that in other breeds at a locus within the 5’-flanking region(P【0.05).These results suggest that differences in body size may be associated with these SNPs of 5’-flanking region and amino acid mutation of the signal peptide of GH in these pig breeds.

Improving school physical education to increase physical activity and promote healthy growth of Chinese school-aged children Time for action

Throughout its more than 5000-year history, China has a long tradition of encouraging active engagement in physical and sport activities This enduring tradition, however, has been facing some major headwinds as China continues to expe- rience demographic and environmental changes related to aging, urbanization, and lifestyle shifts.

<i>Tithonia diversifolia</i>Leaves and Stems Use as Substrate Amendment Promote the Growth of Plantain Vivoplants in the Nursery

Tithonia diversifolia is a year-round weed that decomposes rapidly after application as a soil amendment and it is more and more used in agriculture due to its numerous properties. The use of Tithonia diversifolia in the production of plantain vivoplants is a great opportunity for small holders’ farmers that cannot easily buy chemical inputs for yield improvement. All plant parts are used because of their richness in nutrients, mineral elements and phytochemicals without knowing which part is the most efficient. Tithonia diversifolia used as substrate amendment for plantain vivoplants production in nursery could promote their growth. This study aims to evaluate the effect of T. diversifolia leaves and stems as substrate amendment on plantain vivoplants growth promotion. The vivoplants were produced in substrates amended with T. diversifolia leaves, stems, combination of leaves and stems, and control without amendment. The vegetative growth parameters (number of shoots, height and diameter of shoots, area of shoots leaves) were assessed in sterilized substrate and unsterilized substrate conditions. T. diversifolia leaves and stems treatment increases the number of shoots, the height and the diameter of shoots as well as the area of shoots leaves compared to the control. T. diversifolia stems are the more efficient treatment, followed by the combination of T. diversifolia leaves and stems and finally the T. diversifolia leaves. They act as a biofertilizer promoting thus, the growth of plantain vivoplants in the nursery. All parts of Tithonia diversifolia can therefore be used by poor small holder farmers, as green manure for soil amendment in a green agriculture context.

Research on construction and identification of lentiviral vector of expressing miRNA targeting IGF1R gene regulated by survivin promoter and its inhibition to liver cancer cell growth

Objective： The aim of the study was to investigate the interference and anti-tumor effects of lentiviral vector of miRNA targeting IGF1R gene regulated by survivin promoter. Methods： The fragment of the survivin promoter was acquired by PCR amplification and inserted into pPRIME to recombinant plasmid sur-pPRIME. The complementary DNA containing both sense and antisense Oligo DNA of the targeting sequence was designed, synthesized and cloned into the sur-pPRIME vector, named sur-pPRIME-IGF1R-miR30-shRNA. Viruses were propagated on 293T cells. Viruses were purified by CsCI gradient according to standard techniques, and functional PFU titers were determined by plaque assay on 293 cells. The effect of sur-pPRIME-IGF1R-miR30-shRNA on IGF1R expression of Hep3B cells was detected by RT-PCR and Western blot. The antitumor potential of sur-pPRIME-IGF1R-miR30-shRNA to Hep3B cells was evaluated by CCK-8 assay. Results： sur-pPRIME-IGF1R-miR30-shRNA was constructed successfully. Functional PFU titers of sur-pPRIME-IGF1R-miR30-shRNA were 4.58×10^9 PFU/rnL. Sur-pPRIME-IGF1R-miR30-shRNA was more effective to inhibit IGF1R expression in mRNA or protein levels and the proliferation of Hep3B cells. Conclusion： sur-pPRIME-IGF1R-miR30-shRNA expressing IGF1R-siRNA can inhibit IGF1R expression and may be used for further investigation of gene therapy of liver cancer.

Magnetic nanotechnology to study and promote axon growth

After injury of the central and peripheral nervous systems,functional recovery is impaired by axon regeneration failure.Various approaches for promoting axon growth have been attempted but their low efficacy has prevented them from being clinically applicable.

Research Progress of Mechanism of Action of Plant Growth Promoting Rhizobacteria

The paper first introduces the definition and classification of plant growth promoting rhizobacteria （PGPR）, then reviews the research achievements on the mechanism of action of plant growth promoting rhizobacteria, including growth pro-moting mechanism and bio-control mechanism, subsequently lists the use of excel-lent plant growth promoting rhizobacteria strains in recent years, especial y Pseu-domonas and Bacil us strains, and final y discusses problems existing in this area and points out issues requiring further exploration, including PGPR screening meth-ods, preservation methods, mechanism of action, in order to commercialize PGPR as soon as possible and practical y realize its application to production.

Studies on the Isolation of Endophytic Bacteria from Tomato Plants and Their Growth-promoting Activities

[Objective] The study aimed to investigate the growth-promoting activities of endophytic bacteria from tomato plants.[Method]The endophytic bacteria isolated from different tissues of tomato plants were analyzed for the effects of their growth-promoting activities on the germination and growth of tomato plants.The bacteria with growth-promoting activity were preliminarily identified.[Result]Totally 59 endophytic bacterial strains were isolated from roots and stems of tomatoes,of which 4 showed significantly growth-promoting activity to germination and growth of tomato.The results suggest that these strains are endowed with the potential capability of growth-promoting.[Conclusion]The endophytic bacteria with growth-promoting activity were found among the isolates from tomato plants.This provided a good foundation for utilization of these bacteria with growth-promoting activity.

牙鲆GHR基因Promoter区微卫星序列多态性与生长性状关系的初步研究

采用牙鲆GHR基因5’端Promoter区的1个微卫星标记,对胶南和日照2个牙鲆养殖群体进行了群体遗传多样性的研究,并探索该基因多态性位点与牙鲆生长性状之间的相关性。结果表明,2个群体在该座位的等位基因数为12和9个,有效等位基因数为6.26和5.04个,多态信息含量为0.84和0.80。2个群体该座位的Hardy-Weinberg遗传偏离指数均为正值,并没有显示出杂合子缺失,但各基因型分布频率都在一定程度上偏离Hardy-Weinberg平衡(P<0.01)。连锁分析中发现,在胶南群体中,IM基因型对应的个体在全重、全长、体长、头长、体高和眼径形态学数据中均是最大的;在日照群体中,BC基因型对应的个体在全重、全长、体高、尾柄高、尾柄长和眼径数据中均是最大的;而CJ基因型对应的个体在体长和头长这两组数据中是最大的。该结果为研究GHR基因的变异对鱼类生长发育的影响及探索将该基因作为生长遗传标记的可行性奠定了实验基础。

Determination of Growth-promoting and Antagonistic Action of Endophytic Bacteria Strains Itb57 and Itb295 of Tobacco

[ Objective ] The paper was to study the growth-promoting and antagonistic action of endophytic bacteria strains Itb57 and Itb295 of tobacco to explore their functions in biological control. [ Method] The growth-promoting effects of bacterial suspension ~ff endophytic bacteria Itb57 and Itb295 on tobacco seedling un- der different treatment modes were studied using potting method in greenhouse. The antagonistic action of bacterial suspension of endophytic bacteria Itb57 and Itb295 on Phytophthora nicotianae, Alternaria alternata and Botrytis cinerea were measured by duel culture method. [ Result] Bacterial suspensions of enduphytic bacteria Itb57 and Itb295 had certain growth-promoting effects on tobacco seedling, which could significantly increase the fresh weight and dry weight in aerial part; the growth-promoting effect of soaking ＋ spraying and irrigating treatment was the best. Itb57 strain had good antagonistic action against P. nicotianae. A. alterna- ta and B. cinerea, while Itb295 strain only had good antifungal effect against P. nicotianae. [ Conclusion] The results provided basis for the study and application of tobacco endophytic bacteria strains Itb57 and Itb295 in biocontrol of tobacco diseases.

Multiphasic characterization of a plant growth promoting bacterial strain, Burkholderia sp.7016 and its effect on tomato growth in the field

Aiming at searching for plant growth promoting rhizobacteria (PGPR), a bacterium strain coded as 7016 was isolated from soybean rhizosphere and was characterized in the present study. It was identiifed as Burkholderia sp. based on 16S rDNA sequence analysis, as wel as phenotypic and biochemical characterizations. This bacterium presented nitrogenase activity, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity and phosphate solubilizing ability;inhibited the growth of Sclerotinia sclerotiorum, Gibberel a zeae and Verticil ium dahliae;and produced smal quantities of indole acetic acid (IAA). In green house experiments, signiifcant increases in shoot height and weight, root length and weight, and stem diameter were observed on tomato plants in 30 d after inoculation with strain 7016. Result of 16S rDNA PCR-DGGE showed that 7016 survived in the rhizosphere of tomato seedlings. In the ifeld experiments, Burkholderia sp. 7016 enhanced the tomato yield and signiifcantly promoted activities of soil urease, phosphatase, sucrase, and catalase. Al these results demonstrated Burkholderia sp. 7016 as a valuable PGPR and a candidate of biofertilizer.

Paenarthrobacter nitroguajacolicus can promote cucumber growth and control cucumber corynespora leaf spot

Currently,the disease control in cucumber mainly depends on agrochemicals,which is not an environmentally benign strategy.Biocontrol bacteria not only resist plant pathogens but also promote plant growth,which is ecofriendly and sustainable option.A biocontrol bacterial strain BJ-5 was screened using Corynespora cassiicola as the target pathogen,and BJ-5 was determined to be Paenarthrobacter nitroguajacolicus by morphological and molecular methods.The effect of BJ-5 on C.cassiicola was studied,including the spore germination,cell membrane permeability and infected cucumbers.BJ-5 inhibited the germination of C.cassiicola spores in vitro and led to atrophy and deformation of the C.cassiicola budding tubes.BJ-5 caused the relative extracellular conductivity of C.cassiicola mycelia to increase compared with the control.Additionally,BJ-5 reduced the severity of cucumber corynespora leaf spot of cucumber infected with C.cassiicola.The inhibition efficacy of BJ-5 suspension as a foliar spray against cucumber corynespora leaf spot reached 63%inhibition,which is higher than a 5000-fold dilution of Luna-Son SC fungicide.In addition,BJ-5 was tested on the emergence of cucumber seedlings,recording the biomass and photosynthesis of cucumber during the growth period.BJ-5 at 1.5×10^(5)CFU·mL^(−1)promoted the germination of cucumber seeds and increased biomass and photosynthesis at the adult plant stage.Also,the secondary metabolites of BJ-5 were determined.BJ-5 could produce chitinases,siderophore,cellulase,amylase and protease in the respective medium.Finally,adaptation assay of BJ-5 showed good salt tolerance and good adaptability in alkaline conditions,and that BJ-5 retains inhibition of fungi activity at higher temperatures.This is the first report of the biocontrol by P.nitroguajacolicus with antagonism to C.cassiicola and promote cucumber growth.This study indicates that P.nitroguajacolicus may serve as potential biocontrol agents against cucumber corynespora leaf spot fungus.