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.

Effects of phosphate solubilization and phytohormone production of Trichoderma asperellum Q1 on promoting cucumber growth under salt stress

Salinity is one of the major abiotic stresses limiting crop growth and yield.This study investigated the underlying mechanisms of Trichoderma asperellum Q1 in promoting cucumber growth under salt stress, including the abilities of the strain to solubilize phosphate and to produce phytohormone.The results showed that T.asperellum Q1 could solubilize inorganic or organic phosphate and the activities of phosphatases and phytase could be detected in the culture supernatant.In hydroponic experiments, the growth of cucumber seedlings was increased in the hydroponic system treated by culture filtrate of strain Q1 with tricalcium phosphate or calcium phytate under salt stress.This strain also exhibited the ability to produce indole acetic acid（IAA）, gibberellic acid（GA） and abscisic acid（ABA） in liquid medium without any inducers.The levels of those three phytohormones in cucumber seedling leaves also increased after inoculated with this strain, along with increased root growth and root activities of the plant.These results demonstrated the mechanisms of T.asperellum Q1 in alleviating the suppression effect of salt stress involving the change of phytohormone levels in cucumber plant and its ability of phosphate solubilization.

Soil application of Trichoderma asperellum GDFS1009 granules promotes growth and resistance to Fusarium graminearum in maize

Of diseases affecting maize(Zea mays), Fusarium graminearum is one of the most common pathogenic fungi that cause stalk rot. In the present study, the Trichoderma asperellum GDFS1009 strain was shown to be an effective biocontrol agent against stalk rot. In a confrontation culture test, Trichoderma strain displayed an approximately 60% inhibition rate on the mycelial growth of F. graminearum. In pot trials, the application of 2 g/pot of T. asperellum GDFS1009 granules had the best control effect on stalk rot at the seedling stage(up to 53.7%), while the average plant height and fresh weight were also significantly improved. Additionally when fertilizer was added at 8 g/pot, the application of 3 g/pot of Trichoderma granules had the best control effect on maize stalk rot(40.95%). In field trials, when inoculating F. graminearum alone, the disease index for inoculating was 62.45, but only 31.43 after treatment with T. asperellum GDFS1009 granules, suggesting a control efficiency of 49.67%. Furthermore, in a naturally F. graminearum-infected field, Trichoderma granules, when applied for 3 consecutive years, showed significant control of stalk rot and increased yields.

棘孢木霉(Trichoderma asperellum)产聚半乳糖醛酸酶的特性

聚半乳糖醛酸酶是水解D-半乳糖醛酸α-1,4-糖苷键的酶,在食品工业特别是果蔬加工中具有重要意义。该文研究棘孢木霉(14636)所产聚半乳糖醛酸酶的酶学特性,采用硫酸铵沉淀法、透析袋透析,对粗酶液进行纯化,并以聚合烯酰胺凝胶电泳(sodium dodecyl sulfate polyamide gel electrophoresis,SDS-PAGE)确定其分子质量大小。实验结果表明,该酶的活性区域在29.29-50.46 k Da,聚半乳糖醛酸酶的最适反应pH为4.0,在pH 3.0-5.0稳定性较好,最适温度为40℃,具有一定的热稳定性;在乙酸乙酸钠缓冲溶液中活性较高。催化性能表明,果胶是聚半乳糖醛酸酶的最佳底物,Km值为0.74 mg/m L,Vmax为3 100μg/min;Mn^2+、Mg^2+、Cu^2+、Ca^2+和Tritonx-100对酶有激活作用,Ca^2+和Tritonx-100激活作用较强,Co^2+、Zn^2+、Ba^2+、Li^+、Fe^2+、SDS和Tween-80对该酶有不同的抑制作用;贮藏特性研究表明,该酶即使在30℃下30 d仍保留70%以上酶活性。研究结果为果蔬清洁加工领域新型酶制剂的开发提供理论依据。

Preparation on the basis of Trichoderma asperellum in the system of biological protection of wheat from Fusarium ear scab

During the last century, as the area of wheat grown under advanced grain husbandry has increased worldwide, so too has the importance of Fusarium ear scab (FES) (synonym, Fusarium head blight) caused by several species of the fungus Fusarium. Yield losses due to FES can total 20%-40% and more depending on climatic conditions. During the last twenty years epidemics of FES in cereals have become chronic all over the world, including the United States and Russia. The most destructive of these were observed in 1982, 1986, 1990-1996 in USA and in the south of Russia in 1982, 1984, 1988, 1992. The harmful effect of FES is manifested not only in reduced grain yields, but also in the contamination of grains and grain products with mycotoxins, such as deoxynivalenol (DON) and its derivatives (3-alfa acetyl-DON, 15-alfa acetyl-DON), T-2 toxin and zearalenone. Standard means to control FES (cultural control methodologies, chemical pesticides, and FES resistant varieties) have little effect or are not practical and rarely reduce the accumulation of mycotoxins in grain. We have developed a new technique to reduce FES using biological preparations. The technique utilizes wheat seed pretreatment with a biofungicide “Mycol” in combination with spraying wheat plants during flowering with a yeast preparation. Technology for production of Mycol on the basis of Trichoderma asperellum strain GJS 03-35 (systematics by Samuels) has been developed. This strain shows hyperparasitic activity against a wide spectrum of plant pathogens, including Fusarium graminearum, a causative agent of FES in wheat. Experiments conducted in the United States demonstrated that spraying wheat plants during flowering with the patented yeast Cryptococcus nodaensis OH 182.9 (NRRL Y-30216) reliably reduces FES development. Tests of the Mycol preparation and the yeast OH 182.9 (EOD) have been performed on the spring wheat “Ivolga” in greenhouse conditions (the Moscow region) and on the winter wheat “Kupava” in field trials in the North Caucasian region. An isolate of F. graminearum was used to insure adequate levels of disease development in greenhouse and field experiments. FES disease severity and incidence, as well as mycotoxin accumulation in wheat grains was studied for single or combination treatments with the biological preparations. Mycol (in concentrations 0.1, 0.5, 1.0, 2.0 kg/t of seeds) was used for wheat seed pretreatment. The yeast preparation EOD (2.0×107 cfu/mL) was applied by spraying wheat plants during flowering. Chemical pesticides (Raxyl, TMTD) and a biological preparation Agat-25K were used as alternative control seed treatments. In greenhouse experiments, inoculations of heads with either biological preparation 4 h prior to inoculation with conidia of F. graminearum significantly reduced FES severity. Application with Mycol reduced DON in wheat grains by 6 to 11 fold. EOD alone or, to a lesser extent, in combination was also highly effective in reducing DON content. For treatments consisting of Mycol and EOD, 1000 grain weights were equivalent or higher than for control plants (both infected, and not infected). Wheat seeds obtained from the plants protected by these biological preparations germinated rapidly and possessed high germination rates compared to the FES control. In field trials, Mycol treatments clearly reduced FES symptoms, apparently providing an immunizing effect against FES. Mycol reduced FES severity and enhanced yield of the wheat varieties used. The effect of Mycol used at a minimum test-dose (0.1 kg/t) was not so pronounced. The greatest reduction of FES development was observed at a dose of Mycol of 1.0 kg per 1 t of seeds used in combination with EOD spraying. Experimental results support the contention that the offered technology has good prospects in controlling wheat Fusarium ear scab.

棘孢木霉Trichoderma asperellum在土壤中定殖量的荧光定量PCR检测

为快速准确检测棘孢木霉Trichoderma asperellum在土壤中的定殖量,构建了荧光定量PCR检测体系,并运用该体系对防治黄瓜枯萎病后土壤中的棘孢木霉数量进行了检测。结果表明:所建立的荧光定量PCR检测体系对棘孢木霉DNA特异性强,R^2为0.998,检测限点为15 fg/μL;在灭菌土壤中检测到的棘孢木霉DNA的拷贝数大于1 866 fg/μL时,对黄瓜枯萎病的防治效果高于64.29%;在黄瓜整个生育期内,检测到土壤中的棘孢木霉定殖量呈现先降后升的变化趋势,第7天时,棘孢木霉DNA拷贝数为320 ng/μL,56 d后棘孢木霉DNA拷贝数迅速上升,最高可达5.16×10~4ng/μL,且对黄瓜枯萎病的防治效果为64.29%~76.81%。研究表明,荧光定量PCR方法检测土壤中棘孢木霉数量具有快速、灵敏度高、可靠性强等优点,可用于检测生防菌棘孢木霉施用后的定殖量和生防效果。

Structural Elucidation and Total Synthesis of Trichodermotin A,A Natural α-Glucosidase Inhibitor from Trichoderma asperellum

A pair of alkaloid enantiomers possessing a novel 1-oxaspiro[4.4]non-3-ene-2,7-dione skeleton,trichodermotin A(1),was obtained from the fungus Trichoderma asperellum.Spectroscopic data,X-ray diffraction,and ECD calculations were used to establish its structure and absolute configuration.(−)-1 showed significantα-glucosidase inhibitory activity(IC_(50)=10.1μmol/L vs.60.1μmol/L of positive control).A plausible biosynthetic pathway originating from L-β-phenylalanine was proposed,and a facile total synthesis was further accomplished.The key reaction of our synthetic strategy was a domino aza-Michael/lactonization in one pot,leading to the pivotal 4-amino-oxaspiro[4.4]octane scaffold.

河口底泥来源真菌Trichoderma asperellum对壬基酚的降解路径

从壬基酚(Nonylphenol,NP)污染严重的李村河口底泥中分离纯化出可实验室培养的真菌,以高浓度NP为环境选择压力筛选出了一株目标菌株,18S r DNA确定其归属为棘孢木霉(Trichoderma asperellum)。实验室内研究了该菌株对NP的生物降解过程,LC/MS分析其代谢产物,据此提出了NP可能的生物降解路径。菌株的生长曲线表明NP能促进其生长,该菌株3 d对5 mg/L NP的降解率为71.4%,7 d的降解率达到87.2%,14 d则达到了92.2%。LC/MS分析确定了NP四种代谢产物,分别是2-甲基-1-苯基丁醇、3,5-二羟基苯甲酸、苯二酚和苯甲醚(或苄醇)。提出了两种NP可能的生物降解路径,Ⅰ是最终转化成苯二酚,Ⅱ是最终转化成苯甲醚或苄醇。

The Beneficial Effect of Trichoderma spp. in Seed Treatment of Four Maize (Zea mays L.) Genotypes

Maize is the main crop for Mexicans;however, it is affected by species of fungi causing ear rot. This research aimed to evaluate the effect of T. asperellum T11, T. harzianum T1 4 y T. longibrachiatum T1 40 on some agronomic variables of four maize genotypes. The seeds of the genotypes H-515, Zapata 7, and H-507 were treated with a suspension of Trichoderma spp. to 1 × 108 spores mL-1, using a control (untreated seed), and Benomyl as chemical control. The planting was in Morelos, in a completely random block design with a factorial arrangement. The ear rot was natural. Data were obtained at the end of the crop cycle and processed in SAS 9.4®. H-515 genotype had the greatest effect on the treatment of maize seeds with Trichoderma spp. (5.562 kg);T. asperellum T11 was the strain that stood out with a mean yield of 50 ears in an area of 16 m2 of 4.904 kg, and control of 4.448 kg. Our results are an economic option for farmers to contemplate the use of Trichoderma and obtain its benefits.

棘孢木霉与30%霜霉·嘧菌酯协同防治烟草镰刀菌根腐病

为筛选防治烟草镰刀菌根腐病高效、安全的复配剂,采用菌丝生长速率法测定生防棘孢木霉Tr-0111、化学杀菌剂30%霜霉·嘧菌酯对尖孢镰刀菌(Fusarium oxysporum)的毒力及两者的相容性,同时测定两者混配对尖孢镰刀菌的毒力系数,并通过盆栽试验评价其对烟草镰刀菌根腐病的防治效果。结果表明,30%霜霉·嘧菌酯和棘孢木霉Tr-0111对尖孢镰刀菌均具有较强的毒力,其EC50值分别为0.0643 mL/L、2.36×10^(2)cfu/mL,且两者相容性好。除V30%霜霉·嘧菌酯∶V_(Tr-0111)=4∶6时无增效作用,其他8个混配比例均具有增效作用,其中V_(30%霜霉·嘧菌酯)∶V_(Tr-0111)=7∶3时增效比率最高,为1.16,抑菌率为68.37%。盆栽试验结果表明,V_(30%霜霉·嘧菌酯)∶V_(Tr-0111)=5∶5时,对烟草镰刀菌根腐病的防效最好,为78.18%,其次为7∶3和1∶9,防效分别为77.27%和72.73%,均显著高于单一使用30%霜霉·嘧菌酯和棘孢木霉Tr-0111。因此,可以将0.0643 mL/L 30%霜霉·嘧菌酯和2.36×10^(2)cfu/mL棘孢木霉Tr-0111以5∶5比例混匀复配应用于烟田防治烟草镰刀菌根腐病,减少化学农药使用。

棘孢木霉PT-29与枯草芽孢杆菌S-16共培养对马铃薯枯萎病的防控作用

马铃薯枯萎病是一种土传真菌病害,可对马铃薯整个生育期造成严重危害,在全国主要马铃薯产区都有不同程度的发生。为减少化学药剂防治马铃薯枯萎病带来的弊端,提高生防菌剂效果,研究了棘孢木霉(Trichoderma asperellum)PT-29与枯草芽孢杆菌(Bacillus subtilis)S-16对马铃薯枯萎病主要致病菌尖孢镰刀菌(Fusarium oxysporum)的抑菌效果,并通过盆栽试验测定了2株菌共培养发酵液对马铃薯枯萎病的防治效果及对马铃薯相关防御酶活性的影响。结果表明,2株菌单培养和3种比例共培养发酵液对尖孢镰刀菌均有抑制效果且以PT-29与S-16共培养发酵液组合B1T1(比例为1∶1)抑制效果最佳;单培养S-16的发酵液(B)处理对马铃薯枯萎病的防效为60.09%,单培养PT-29的发酵液(T)处理对马铃薯枯萎病的防效为54.85%,B1T1处理对马铃薯枯萎病的防效达到73.44%。此外,B1T1+FO(接种尖孢镰刀菌)处理的马铃薯叶片过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、过氧化物酶(POD)、苯丙氨酸解氨酶(PAL)活性明显高于FO处理,峰值相比于FO处理分别提高56.44%、766.89%、111.84%、179.34%。综上所述,PT-29与S-16共培养发酵液对马铃薯枯萎病的防治效果高于单培养发酵液,为复合微生物防治马铃薯枯萎病提供了理论支持。

耐热嗜酸β-甘露聚糖酶TaMan5A在毕赤酵母中高效表达及酶学性质研究

甘露聚糖酶是一类将甘露聚糖降解为短链甘露寡糖及甘露糖的水解酶。为了开发耐酸耐高温的工程酶,从棘孢木霉(Trichodema asperellum)ND-1中克隆甘露聚糖酶基因TaMan5A并在毕赤酵母(Komagataella phaffii)X-33中成功表达。结果显示,该酶的蛋白质分子质量约为67 kDa。最适pH值和温度分别为4.0和65℃,在pH 2.0~6.0具有较强的稳定性,孵育1 h后仍具有80%的活性,且在20~65℃时,残留酶活力均能达到90%以上。1 mmol/L Co^(2+)、脲和5 mmol/L SDS、Zn^(2+)、Fe^(2+)、Mn^(2+)、Ni^(2+)对TaMan5A的活力都有不同程度的激活作用。由于玉米秸秆富含纤维素与半纤维素,因此进一步确定了TaMan5A水解秸秆的最佳组合条件(玉米秸秆用量0.5 g,TaMan5A用量0.5 g,pH 4.0,水解2 d),并得到玉米秸秆用量和TaMan5A用量对玉米秸秆降解效率影响最大。该研究首次从棘孢木霉ND-1中克隆出TaMan5A基因,实验结果表明,TaMan5A是一种嗜酸、耐高温、热稳定性强的酶,具有较大的应用前景,值得进一步研究。

盆栽蓝莓根际接种内生真菌的效应

自然条件下,内生真菌能促进蓝莓生长。从正常生长蓝莓根系分离、筛选获得两株内生真菌棘孢木霉(Trichoderma asperellum)和卷枝毛霉(Mucor circinelloides),将其接种至盆栽蓝莓根际灭菌基质中,分析其对蓝莓植物形态指标、光合能力、根系生长和生物量的影响。结果发现,与不接菌(CK)相比,接种棘孢木霉和卷枝毛霉的叶片SPAD值、叶片净光合速率、根长、体积、根表面积、根系活力、株高、分枝数、地径、叶片数和生物量均显著增加。人工接种棘孢木霉和卷枝毛霉能够显著促进蓝莓生长发育,具有良好应用前景。

棘孢木霉对向日葵幼苗抗氧化酶活性及菌核病防效的影响

试验于2021年5—8月,采用筛选出的对向日葵菌核病菌有较好拮抗作用的棘孢木霉Trichoderma asperellum 581,通过盆栽试验,测定不同施用浓度对向日葵幼苗生长、抗氧化酶活性以及对向日葵菌核病防效的影响。结果显示:T.asperellum 581不同施用浓度均能提高对向日葵菌核病的防效,以T3(即木霉菌处理浓度为1×10^(5)个·mL^(-1))应用效果最好,对向日葵菌核病的防效达到98.77%。与CK1(即只利用向日葵菌核病菌灌根且不施用木霉悬浮液)相比,T.asperellum 581不同施用浓度均能提高向日葵幼苗株高、茎粗、全株鲜质量和根冠比,以T3处理对向日葵幼苗形态建成和物质积累的促进效果最好,株高、茎粗、全株鲜质量、全株干质量、根冠比和壮苗指数分别比CK1提高64.71%、193.55%、99.15%、188.24%、50.00%、416.67%;T.asperellum 581不同施用浓度均能提高向日葵幼苗叶片中过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、苯丙氨酸解氨酶(PAL)、抗坏血酸过氧化物酶(APX)、多酚氧化酶(PPO)活性,以T3处理对向日葵幼苗抗氧化酶促进效果最好,在播种后35 d,向日葵幼苗叶片中POD、CAT、SOD、PAL、APX和PPO活性分别比CK1提高了64.35%、35.62%、59.14%、50.02%、43.39%、41.16%。研究表明T.asperellum 581通过提高向日葵幼苗抗氧化酶活性促进了幼苗形态建成和物质积累,提高了对向日葵菌核病的防治效果。

棘孢木霉152-42诱导多年生黑麦草抗褐斑病的机理初探

为探究棘孢木霉(Trichoderma asperellum)诱导多年生黑麦草(Lolium perenne L.)抗褐斑病的机理,本研究以多年生黑麦草为材料,通过棘孢木霉和玉蜀黍丝核菌(Rhizoctonia zeae)平板对抗、盆栽多年生黑麦草木霉灌根诱导后接种玉蜀黍丝核菌,检测棘孢木霉菌株152-42对玉蜀黍丝核菌引起的褐斑病的防治效果,分析其防病机理。结果表明:共培养7 d时棘孢木霉152-42对玉蜀黍丝核菌的抑制率达到100%;棘孢木霉152-42显著降低了盆栽多年生黑麦草褐斑病的发病率;相较于未经木霉诱导的染病叶片,木霉诱导处理的染病叶片超氧化物歧化酶活性显著升高,丙二醛含量显著降低,抗病相关基因PR-1和PR-5的表达量显著提高。因此,棘孢木霉152-42不仅能显著抑制玉蜀黍丝核菌生长,而且可以诱导多年生黑麦草通过提高抗病相关酶活性,调控抗病相关基因的表达等提高抗病性,是一种极具开发潜力的草坪病害生防真菌。

生防菌棘孢木霉的分离鉴定及生物学特性研究

本试验从羊茅草根际土壤中分离筛选出生防菌株GT30,经形态学和分子生物学鉴定,确定GT30为棘孢木霉,并对其生物学特性和抑菌效果进行研究。结果显示,菌株GT30菌丝生长较快;孢子梗对生生长,主分支呈树状;分生孢子呈球形,外璧光滑。棘孢木霉GT30最适生长pH值为5~6,最适温度为25~30℃,葡萄糖和牛肉膏分别是GT30生长所需最佳碳源和氮源,光照有利于GT30产孢,Mg^(2+)和Ca^(2+)离子可促进GT30菌丝生长及产孢。平板对峙培养试验表明,棘孢木霉GT30对大蒜白斑病菌和葡萄炭疽病菌抑制效果较好,抑菌率分别为63.7%和61.4%。本研究结果可为开发优异生防木霉菌剂提供菌种资源和理论基础。

改变培养条件下藻栖棘孢木霉cf44-2中的没药烷类倍半萜衍生物的分离纯化与鉴定

通过改变培养条件,并采用硅胶柱层析、反相硅胶柱层析、Sephadex LH-20凝胶柱层析、制备薄层层析、半制备高效液相色谱等分离纯化手段,从棘孢木霉cf44-2发酵产物中获得8个没药烷类倍半萜衍生物,包含5个降没药烷倍半萜。通过^(1)HNMR、^(13)CNMR分析并与文献比对,将其鉴定为(3S^(*),6 R^(*),7S^(*))-zingiberenol(1)、(6 R^(*),7S^(*))-2,10-bisaboladien-1-one(2)、trichodone A(3)、trichobisabolin Z(4)、trichobisabolin Q(5)、trichobisabolin N(6)、trichobisabolin S(7)和trichobisabolin M(8)。化合物2~8是在改变培养条件下获得的新的没药烷类倍半萜衍生物,其中部分化合物具有一定的生物活性。表明,改变培养条件是使棘孢木霉中萜类代谢产物多样化的有效途径,为深入挖掘棘孢木霉次级代谢产物提供了依据。

棘孢木霉天冬氨酸蛋白酶基因的克隆表达及其对大豆分离蛋白的水解

为开发木霉天冬氨酸蛋白酶的应用潜能,采用实时聚合酶链式反应技术,从棘孢木霉(Trichoderma asperellum)中克隆蛋白酶基因asp,并在毕赤酵母(Pichia pastoris)GS115中成功表达,进一步对重组蛋白酶rAsp进行分离纯化,分析其生化特性及对大豆分离蛋白的水解作用。结果显示,asp基因编码的蛋白酶属于天冬氨酸蛋白酶家族,其序列与本家族成员序列相似性最高为47.74%。在三角瓶中诱导表达时,发酵液中rAsp的酶活力为25.8 U/mL。rAsp最适反应pH值和温度分别为2.5和45℃,在pH 2.0~6.0范围和45℃以下具有较强的稳定性。Cu^(2+)和Mn2+具有促进rAsp活性的作用,而Fe^(3+)、十二烷基硫酸钠和胃蛋白酶抑制剂显著抑制rAsp的活性。rAsp对大豆分离蛋白的水解效率较商业化胃蛋白酶高7.7%;同时,降低β-伴大豆球蛋白和球蛋白致敏性的能力分别是胃蛋白酶的1.4倍和1.8倍。因此,rAsp在大豆蛋白加工应用中具有潜在的开发价值。

海洋生境棘孢木霉菌TCS007对植物的促生长及诱导抗逆作用

为研究海洋生境棘孢木霉菌Trichoderma asperellum TCS007对植物的促生长及诱导抗逆作用,以黄瓜和水稻为试材,评价菌株TCS007对植物种子萌发、幼苗和根系生长等生长量及其对叶绿素、可溶性糖和蛋白含量的影响,并在低温和高盐胁迫条件下,研究其对植株生长相关生理指标影响。结果表明:1×10^(6)CFU/mL的TCS007孢子悬浮液可以显著促进黄瓜种子萌发,且处理后黄瓜幼苗的株鲜重、叶面积、根鲜重及根系活力分别提升13.53%、17.97%、66.67%和27.30%,总叶绿素、可溶性糖和可溶性蛋白含量分别增加22.75%、18.24%和8.60%;在5℃、10℃和15℃低温胁迫下,1×10^(6)CFU/mL的TCS007孢子悬浮液显著提高了黄瓜叶片中过氧化物酶(POD)和超氧化物歧化酶(SOD)的活性,降低了丙二醛(MDA)含量和相对电导率(REC);在0.1 mol/L的氯化钠(高盐)胁迫下,不同含量的TCS007孢子悬浮液均可显著缓解氯化钠对水稻幼苗的盐害作用,且随着孢子含量的增高,缓解效果越为明显,其中添加5%1×10^(6)CFU/mL TCS007孢子悬浮液的水稻幼苗POD、SOD和过氧化氢酶(CAT)活性均显著增加并能降低其REC。综上,棘孢木霉菌TCS007对植物具有良好的促生长效果和诱导抗逆作用,研究结果可为其开发成为新型生物农药提供理论依据。

海洋生境棘孢木霉TCS007缓解蚕豆干旱胁迫的研究

木霉属真菌(Trichoderma spp.)是一类有益微生物,不仅能促进植物生长,还能诱导植物对生物和非生物胁迫产生耐受性。实验室前期分离获得一株来自南极海洋沉积物的菌株TCS007,并鉴定其为棘孢木霉Trichoderma asperellum,研究表明,TCS007可显著提高植物抗盐、抗寒能力。本文以蚕豆为试材,从生理生化水平上研究了TCS007在诱导植株抗旱性方面的作用。采用温室盆栽法对不同处理条件下蚕豆的各项生理生化指标进行了测定。结果表明:在干旱胁迫下,经TCS007孢子悬浮液处理的蚕豆幼苗的株高、株重、根鲜重和总叶绿素含量相较于空白对照(CK)分别增加了28.7%、42.9%、34.2%和26.2%;叶片中的总糖、总蛋白含量和相对含水量在不同的时间点分别增加了11.1%~106.0%、38.0%~68.8%和7.0%~19.0%;蚕豆根、茎和叶中超氧化物歧化酶(SOD)活性分别增加了28.8%、13.3%和8.0%,过氧化物酶(POD)活性分别增加了10.8%、22.4%和14.8%,丙二醛(MDA)含量分别降低了37.2%、14.7%和12.1%;此外,蚕豆根、茎和叶中植物激素脱落酸(ABA)含量在不同的时间点分别增加了21.1%~33.2%、44.9%~60.6%和28.2%~78.7%,生长素吲哚乙酸(IAA)含量分别增加了20.9%~29.0%、19.7%~37.3%和11.1%~23.8%。由此可见,用TCS007孢子悬浮液处理可以缓解干旱胁迫对蚕豆生长造成的影响,从生理生化水平上提高蚕豆的抗旱能力。本研究结果可为TCS007开发成为木霉生物菌肥产品提供理论依据。