Department of Biotechnology, College of Agriculture, Junagadh Agricultural University, Junagadh, Gujarat, 362 001, India.
Arch Microbiol. 2023 May 19;205(6):242. doi: 10.1007/s00203-023-03582-0.
Trichoderma isolates were inhibited variably in-vitro growth of soil-borne phytopathogen Macrophomina phaseolina (Maubl.) Ashby causes root rot in cotton. The growth inhibition of test-pathogen was found to be higher (90.36%) in T. viride NBAIITv23 followed by T. koningii MTCC796 (85.77%) under dual culture antagonism. The microscopic examination suggested that the antagonists Tv23 and MTCC796 adopted mycoparasitism as a strong mode of action to restrain pathogen growth. However, antagonists T. harzianum NBAIITh1 (77.89%) and T. virens NBAIITvs12 (61.74%) demonstrated strong antibiosis action for growth inhibition of the test pathogen. A significant positive correlation was established between the growth inhibition of M. phaseolina and the release of cell wall degrading enzymes- chitinase (p = 0.001), β-1,3, glucanase (p = 0.01), and protease (p = 0.05) under the influence of pathogen cell wall. The chitinase and β-1,3, glucanase activities were elevated 2.09 and 1.75 folds, respectively, in potent mycoparasitic Tv23 strain influenced by a pathogen cell wall compared to glucose as a carbon source. The three unique DNA-RAPD fragments OPA-07, OPA-16, and OPO-15 amplified by potent mycoparasitic Tv23 strain, were subjected to DNA sequencing and derived functional 864 bp from OPA-16 and have sequence homology to ech42 gene with partial CDs of 262 amino acids (nucleotide accession No. KF723016.1 and protein accession No.AHF57046.1). Novel SCAR markers were developed from a functional sequence of OPA-16 fragments and validated across the genomic DNA of eleven Trichoderma antagonists. The novel SCAR markers evolved from the RAPD-SCAR interface to authenticate chitinolytic Trichoderma associated with mycoparasitic action for eco-friendly biocontrol activity.
木霉分离株在体外生长中对土壤病原菌大丽轮枝菌（Macrophomina phaseolina）（Maubl.）Ashby 表现出不同程度的抑制作用，导致棉花根腐病。在双培养拮抗作用下，测试病原菌的生长抑制率最高（90.36%）为绿色木霉 NBAIITv23，其次是哈茨木霉 MTCC796（85.77%）。显微镜检查表明，拮抗剂 Tv23 和 MTCC796 采用真菌寄生作为一种强有力的作用方式来抑制病原体的生长。然而，拮抗剂哈茨木霉 NBAIITh1（77.89%）和深绿木霉 NBAIITvs12（61.74%）表现出强烈的抑菌作用，抑制测试病原体的生长。在病原体细胞壁的影响下，大丽轮枝菌的生长抑制与细胞壁降解酶几丁质酶（p=0.001）、β-1,3-葡聚糖酶（p=0.01）和蛋白酶（p=0.05）的释放之间建立了显著的正相关。与葡萄糖作为碳源相比，在受病原体细胞壁影响的强真菌寄生的 Tv23 菌株中，几丁质酶和β-1,3-葡聚糖酶的活性分别提高了 2.09 倍和 1.75 倍。由强真菌寄生的 Tv23 菌株扩增的三个独特的 DNA-RAPD 片段 OPA-07、OPA-16 和 OPO-15，经过 DNA 测序，从 OPA-16 中获得了具有功能的 864 bp，并与 ech42 基因具有序列同源性，其部分 CD 为 262 个氨基酸（核苷酸注册号 KF723016.1 和蛋白质注册号 AHF57046.1）。从 OPA-16 片段的功能序列中开发了新型 SCAR 标记，并在 11 种木霉拮抗物的基因组 DNA 上进行了验证。从 RAPD-SCAR 界面进化而来的新型 SCAR 标记用于鉴定与真菌寄生相关的具有几丁质酶活性的木霉，以实现生态友好型生物防治活性。
