Development of biofertilizers for sustainable agriculture over four decades(1980-2022)

The application of biofertilizers is becoming an inevitable trend to substitute chemical fertilizers for sustainable agriculture.To better understand the development of biofertilizers from 1980 to 2022,we used bibliometric mining to analyze 12,880 journal articles related to biofertilizer.The network cooccurrence analysis suggested that the biofertilizers research can be separated into three stages.The first stage(1980-2005)focused on nitrogen fixation.The second stage(2006-2015)concentrated on the mechanisms for increasing plant yield.The third stage(2016-2022)was the application of biofertilizers to improve the soil environment.The keyword analysis revealed the mechanisms of biofertilizers to improve plant-growth:biofertilizers can impact the nutritional status of plants,regulate plant hormones,and improve soil environments and the microbiome.The bacteria use as biofertilizers,included Pseudomonas,Azospirillum,and Bacillus,were also identified through bibliometric mining.These findings provide critical discernment to aid further study of biofertilizers for sustainable agriculture.

Synthesis and plant-growth regulatory activities of novel imine derivatives containing 1H-1,2,4-triazole and thiazole rings

Eleven new imine derivatives 6 containing 1H-1,2,4-triazole and thiazole rings were synthesized by the condensation of 5-((1H- 1,2,4-triazol-1-yl)methyl)-4-tert-butylthiazol-2-amine with various substituted benzaldehydes.The structures of the title compounds were characterized by ~1H NMR,MS and elemental analysis.The plant-growth regulatory activities of these compounds were evaluated.The primary bioassay results indicated that these target compounds exhibited promising plant-growth regulatory activities.

Novel Synthesis, Crystal Structure, and Plant-growth Regulation Activity of(1S,4R)-4,7,7-Trimethyl-6-oxabicyclo[3.2.1]octane-1,4-diol

The title compound,（1S,4R）-4,7,7-trimethyl-6-oxabicyclo [3.2.1] octane-1,4-diol（C（10）H（18）O3）, has been synthesized from terpinolene via one-step catalytic synthetic method and structurally characterized by means of HRMS, IR, 1H-NMR, （13）C-NMR and single-crystal X-ray diffraction. The compound crystallizes in trigonal, space group R-3, with a = 27.892（9）, b = 27.892（9）, c = 6.720（2） A, γ = 120°, Z = 18, V = 4527（3） A3, Dc = 1.230 g/cm3, Mr = 186.24, λ（Mo Kα） = 0.71073？, μ = 0.09 mm（-1）, F（000） = 1836, the final R = 0.051 and wR = 0.161. The title compound molecule contained a 6-oxabicyclo[3.2.1]octane skeleton and two hydroxyl groups, which were connected through intermolecular O–H…O hydrogen bonds to generate a two-dimensional network. Especially, the preliminary bioassay showed that the title compound can promote the root growth and shoot elongation of rape（Brassica campestris） at low concentration（0.62570 mmol·L^-1） and inhibit them at high concentration（〉 70 mmol·L^-1）.

STUDIES ON STEROID PLANT-GROWTH REGULATOR 27.ENHANCED PRODUCT DIASTEREOMERIC EXCESSES IN ASYMMETRIC DIHYDROXYLATION OF THE(22E,24R)-AND THE(22E,24S)-24-ALKYL STEROIDAL UNSATURATED SIOECHAIN BY USING THE SHARPLESS IMPROVED CHIRAL LIGAND

The osmium tetroxide catalyzed asymmetric dihydroxylation of the(22E)- steroidal sidechain is described and an unexpected 8:1 ratio of(22R,23R)and (22S,23S)was obtained from the(22E,24S)-24-ethyl substituted sidechain.

解磷、固氮、产吲哚乙酸微生物菌株的筛选及其对植物的促生效果

通过对1 539株分离自水稻田、庐山、辣椒田和番茄田4种土壤环境的细菌菌株进行解磷、固氮、产吲哚乙酸菌株活性的平板分析,筛选得到具有代表性活性菌株276株。对这些菌株进行了2次温室促生试验,选择具有代表性的134株菌株,分析了这些解磷、固氮、产吲哚乙酸菌株各个因素与促生的相关性,及菌株来源地与促生结果间的相关性,并对18株温室试验效果比较好的菌株进行了定殖力测定和大田试验。研究发现,解磷、固氮、产吲哚乙酸活性与植物促生效果间存在明显的正相关,解磷、固氮活性对植物的影响要大于产吲哚乙酸(IAA)活性对植物的影响;不同来源地点所筛选得到的菌株对不同植物的促生效果不同,来源于番茄田的菌株对植物的促生效果要优于其他3种土壤来源的菌株。优势菌株12LY101、12LY027、R112.11具有较高的定殖能力和对作物的促生效果。

Effect of acid phosphatase produced by Trichoderma asperellum Q1 on growth of Arabidopsis under salt stress

Salt stress is a major environmental factor that inhibits crop growth.Trichoderma spp.are the most efficient biocontrol fungi and some of the strains can stimulate plant growth.Phosphate solubilization is known as one of the main mechanisms in promoting plant growth,but the underlying mechanisms of phosphate solubilization in the salinity still need to be explored.The Trichoderma asperellum Q1 isolated and identified in our lab is a beneficial rhizosphere biocontrol fungus with a high phosphate solubilization activity.It could produce acid and alkaline phosphatases when using insoluble organic phosphorus as the sole phosphorus source,the salt stress increased the phosphorus-solubilization ability of the strain and the activities of the two enzymes.Furthermore,an acid phosphatase was purified from the fermentation broth by ammonium sulphate precipitation,ion-exchange,and gel filtration chromatography.Its molecular weight was 55 k Da as determined by SDS-PAGE.The purified acid phosphatase was used to investigate growth performance of Arabidopsis thaliana by plate assay and the result showed that it contributed to Arabidopsis growth by transforming organic phosphate into a soluble inorganic form under salt stress.To our knowledge,this is the first report on acid phosphatase purification from T.asperellum and its function in regulation of plant growth under salt stress.

Effect of a High Silver Stress on the Element Transfers from a Smectite-Type Clay Substrate to Plants

Two species of radishes, Raphanus sativus and Raphanus raphanistrum, were grown in the laboratory in the same substrate consisting of a smectite-type clay, which was watered at the beginning of the experience with 50 ml of a solution containing either none or 1000, 2000 or 4000 mg/L of AgNO3, respectively. Occurrence of the toxic metal in the substrate outlines higher element uptakes by the cultivated species Raphanus sativus than by the wild species Raphanus raphanistrum, except for the highest degree of Ag pollution. After a one-month growth in the Ag-polluted substrate, Raphanus sativus was depleted in most of the major, trace and rare-earth elements, except for Al, Fe, Th, Ag and U that increased in the radishes from substrate polluted by 2000 mg/L of AgNO3, and Sr, Co, Ni, U and Ag that increased in the radishes from substrate polluted by 4000 mg/L of AgNO3. Raphanus raphanistrum was enriched in all elements except Si, Na, Rb and K in the polluted substrate. The uptake was monitored by a cation-exchange process in the rhy-zosphere between mineral particles and the watering solution in the presence of various enzymes with specific activities that induced a variable uptake with the REEs being even fractionated. These activities most probably depend on combined factors, such as the plant species, and the chemical and physical properties of the substrate. The results obtained here reveal also that accumulation of nutrient elements and others in the plants is not uniform at a given Ag pollution of the substrate and therefore at a given Ag contamination in the same plant species.

Persistence and Impact of a PGPR on Microbial Communities of Biosolids and Soil Amended with Them

Survival of the plant-growth promoting rhizobacteria （PGPR） strain Pseudomonasfluorescens 92 in two batches ofbiosolids and soil amended with them and functional and structural shifts occurring in the resident bacterial communities were assessed. Viability of the rifampicin resistant gfp-tagged P. fluorescens 92RTcgfp, inoculated in microcosms consisting of biosolids, soil amended with biosolids and soil, drastically decreased 3-7 days after inoculation in treatments containing biosolids and soil amended with them. The PGPR counts in biosolids were always lower than in soil throughout the experiment whereas, in soil amended with biosolids, were similar or higher depending on the batch of biosolid. Analysis of the community-level physiological profiling （CLPP） revealed a strong impact of the strain on the metabolic activities, as seen in a general uniformity of the inoculated microcosms profiles. According to single-strand conformation polymorphism （SSCP） analysis, the presence of the PGPR had no effect on the resident soil and biosolid eubacterial population, whereas it induced a transient shift in the composition of the resident pseudomonads. In conclusion, biosolids themselves are not suitable as inoculum vehicle for the PGPR nevertheless, their combined incorporation into soil increases the inoculum survival and buffers the competition effects with the resident communities.

A novel blue-light excitable Pr^(3+)doped(Sr,Ba)LaMgTaO6 phosphor for plant growth lighting

In this work,a series of Pr^(3+)ions doped(Sr,Ba)LaMgTaO_(6)phosphors were prepared and applied for plant growth lighting.Under 450 nm excitation,(Sr,Ba)LaMgTaO_(6):Pr^(3+)exhibits intense reddish emission at around 650 nm which is assigned to the3p0→3F2transition of Pr^(3+)ions.The luminescence intensity reaches to the maximum at 2.5 mol%Pr^(3+)doping content both in SrLaMgTaO_(6):Pr^(3+)and BaLaMgTaO_(6):Pr^(3+)systems.Meanwhile,the internal quantum efficiency(IQE)test shows that the IQE of the SrLaMgTaO_(6):0.025Pr^(3+)phosphor is 33.34%upon blue light excitation.The decay curves and temperature-dependent luminescence measurements of the(Sr,Ba)LaMgTaO_(6):Pr^(3+)phosphors were performed and investigated in detail.The red light emitting diodes(LEDs)were packaged using the SrLaMgTaO_(6):Pr^(3+)and BaLaMgTaO_(6):Pr^(3+)phosphors combined with a blue LED chip,which are welloverlapped with the absorption band of photosynthesis.Results indicate that the(Sr,Ba)LaMgTaO_(6):Pr^(3+)can serve as a component of the red light in plant-growth LEDs.

PopW蛋白对黄瓜霜霉病的防病促生作用

前期研究发现来源于青枯菌(Ralstonia solanacearum,ZJ3721)的Harpin蛋白PopW对多种作物有较好的诱导抗病作用。本文研究PopW蛋白在温室和田间条件下对黄瓜霜霉病的生防和促生效果。温室试验结果表明:人工接种霜霉病病原菌后15 d,250 mg/L PopW蛋白水溶液对黄瓜霜霉病的防效最好(42.85%),PopW蛋白(250 mg/L)处理的黄瓜苗与对照相比生物量增加26.92%,叶绿素含量显著提高。2010年,PopW蛋白(250 mg/L)间隔15 d喷雾1次,共使用3次。初次喷雾后8、25、35和48 d,对黄瓜霜霉病的生防效果分别为41.87%、48.36%、53.21%和50.85%;2011年,等量的PopW蛋白间隔10 d使用1次,共使用3次。初次喷雾后的第8、15、22和27 d,生防效果分别为47.07%、48.17%、50.59%和54.48%。试验结果表明,250 mg/L PopW蛋白水溶液可作为黄瓜霜霉病的潜在生防因子,且其抗病作用有一定的持效期,可保持10～15 d,甚至更长时间。分析PopW蛋白处理对黄瓜的促生作用及其对黄瓜品质的影响,结果显示:PopW蛋白处理组黄瓜单株增产达33.01%。PopW蛋白处理的黄瓜果实可溶性蛋白、可溶性糖、游离氨基酸和维生素C含量分别为18.07 mg/g、6.80 mg/g、60.20 mg/100 g、68.27μg/g,均显著高于对照(10.21 mg/g、5.30 mg/g、59.06 mg/100 g、49.55μg/g),结果表明PopW蛋白处理可显著提高黄瓜产量、改善黄瓜品质。

Mutualistic fungal endophytes produce phytohormones and organic acids that promote japonica rice plant growth under prolonged heat stress

This study identifies the potential role in heat-stress mitigation of phytohormones and other secondary metabolites produced by the endophytic fungus Paecilomyces formosus LWL1 in japonica rice cultivar Dongjin. The japonica rice was grown in controlled chamber conditions with and without P. formosus LWL1 under no stress （NS） and prolonged heat stress （HS） conditions. Endophytic association under NS and HS conditions significantly improved plant growth attributes, such as plant height, fresh weight, dry weight, and chlorophyll content. Furthermore, P. for- mosus LWL1 protected the rice plants from HS compared with controls, indicated by the lower endogenous level of stress-signaling compounds such as abscisic acid （25.71%） and jasmonic acid （34.57%） and the increase in total protein content （18.76%-33.22%）. Such fungal endophytes may be helpful for sustainable crop production under high environmental temperatures.

Synthesis and biological activity of new heterocyclic compounds 5-[(1,1-dimethyl)ethyl]-3-aryl- (1H-1,2,3-triazol- 1-yl)-5-isoxazolidinols

In this paper new heterocyclic compounds 5-[(1,l-dimethyl)ethyl]-3-aryl-(1H-1,2,3-traizol-1-yl)-5-isoxazolidinols were obtained by the reaction of vinyl triazole derivatives with hydroxylamine hydrochloride under the action of sodium carbonate. The biological tests indicate that they had plant-growth regulating activity.