Microbial Technology Division, CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226 001, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-HRDC, Kamla Nehru Nagar, Ghaziabad, Uttar Pradesh, 201 002, India.
Microbial Technology Division, CSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226 001, India.
Plant Physiol Biochem. 2024 Oct;215:108953. doi: 10.1016/j.plaphy.2024.108953. Epub 2024 Jul 23.
Bioactive secondary metabolites from fungi, including Trichoderma, are an excellent source of plant biostimulants. Although production of novel biostimulants from known microbes is critical, challenging them may produce novel bioactive compounds. With this hypothesis, the study used live Fusarium chlamydosporum (FOL7) culture as the inducer during T. harzianum (IF63) growth in broth. Plate assays and gas chromatography-mass spectrometry (GC-MS) analysis were used to characterise the metabolites. Microscopy, pot experiments and, biochemical estimations of the defence-related enzymes in tomato plants established the biostimulant activity of the induced Trichoderma metabolites. Fungal crude metabolites (FCM) obtained from IF63+FOL7 extracts (TF.ex) showed increased antimicrobial activity. TF.ex at 50 μg mL, inhibited the FOL7 growth by 68.33% compared to the Trichoderma alone extract. Scanning electron microscopy (SEM) revealed morphological disruption of FOL7 mycelia by TF.ex. GC-MS analysis of the extracts revealed the presence of approximately 64 compounds, of which at least 13 were detected explicitly in TF.ex. Methyl (3-oxo-2-pentylcyclopentyl) acetate (Methyl dihydrojasmonate), a lipid functionally related to jasmonic acid, was the major metabolite (∼21%) present in TF.ex. Tomato seed dressing with TF.ex promoted plant growth and induced systemic resistance against FOL7 compared to alone Trichoderma and Fusarium extracts. The TF.ex treatment increased the superoxide dismutase (33%) and catalase activity by 2.5-fold in tomato plants. The study concludes that fungal secondary metabolites may be modulated by providing appropriate challenges to produce effective metabolite-based biostimulants for agricultural applications.
真菌（包括木霉属真菌）的生物活性次生代谢产物是植物生物刺激素的极好来源。虽然从已知微生物中生产新型生物刺激素至关重要，但对其进行挑战可能会产生新型生物活性化合物。基于这一假设，本研究在液体培养基中生长哈茨木霉（T. harzianum，IF63）时，使用活的盾壳霉（Fusarium chlamydosporum，FOL7）培养物作为诱导物。通过平板分析和气相色谱-质谱联用（GC-MS）分析来表征代谢产物。显微镜观察、盆栽试验和番茄植株防御相关酶的生化测定确定了诱导的哈茨木霉代谢产物的生物刺激活性。从 IF63+FOL7 提取物（TF.ex）中获得的真菌粗代谢产物（FCM）显示出增强的抗菌活性。与单独使用木霉属提取物相比，TF.ex 浓度为 50μg/mL 时，抑制 FOL7 生长 68.33%。扫描电子显微镜（SEM）显示 TF.ex 破坏了 FOL7 菌丝体的形态。提取物的 GC-MS 分析表明，大约有 64 种化合物存在，其中至少有 13 种在 TF.ex 中被明确检测到。Methyl (3-oxo-2-pentylcyclopentyl) acetate（Methyl dihydrojasmonate），一种与茉莉酸功能相关的脂类，是 TF.ex 中主要的代谢产物（约 21%）。与单独使用木霉属和尖孢镰刀菌提取物相比，用 TF.ex 对番茄种子进行包衣处理可促进植物生长并诱导植株对 FOL7 产生系统抗性。TF.ex 处理使番茄植株中超氧化物歧化酶（33%）和过氧化氢酶活性分别增加了 2.5 倍。本研究得出结论，通过为产生有效的基于代谢物的生物刺激素提供适当的挑战，真菌次生代谢产物可能会被调节，从而可将其应用于农业。
