Roy Tina, Bandopadhyay Anuradha, Majumdar Sukanta, Alam Shariful, Das Nirmalendu
Post Graduate Department of Botany, Barasat Government College, Barasat, Kolkata, 700124, India.
Department of Botany, University of Gour Banga, Malda, West Bengal, 732103, India.
Curr Microbiol. 2025 Feb 2;82(3):109. doi: 10.1007/s00284-025-04083-7.
Enzymatic and antioxidative responses are key defense mechanisms in plants following pathogen invasion, collectively known as induced systemic resistance (ISR). Alternaria sp., a well-known soil-borne pathogen, causes blight diseases in various crops. This study investigates the defence response in lentil plants through the treatment-induced application of two multipotent pesticide degrading plant growth-promoting rhizobacteria (PGPR), Bacillus cereus and Bacillus safensis, to mitigate the destructive effects of Alternaria. Both bacterial strains were applied in different carrier-based bioformulations via soil drenching. We assessed the modulation of defense-related enzymes by various combinational treatments with the Alternaria pathogen. The in vitro production of antimicrobial compounds was analyzed using GC-MS to confirm their pathogen-suppressive capabilities. Field trials showed a positive correlation between treatments and improvements in yield and growth index (GI). The highest (180%) enzymatic induction of phenylalanine ammonia lyase (PAL) followed by catalase (CAT)(100%) and polyphenol oxidase (PPO) (54%), was observed in treatments with B. cereus alone or in combination with B. safensis, in presence of Alternaria, in respect to the control. In vitro analysis revealed the production of antimicrobial compounds, including benzoic acid derivatives, cyclotetrasiloxanes, hexacosane, chlorpyrifos, and phthalates, which may contribute to pathogen suppression. Our findings demonstrate that these biocontrol agents (BCAs) not only stimulate the plant's enzymatic defense system but also enhance growth, seed yield and produce several antimicrobial compounds in vitro. Thus, pesticide-tolerant PGPR, used in this study, exhibit both disease control and plant growth-promoting properties, offering promising applications in sustainable agriculture.
酶促反应和抗氧化反应是植物在病原体入侵后的关键防御机制，统称为诱导系统抗性（ISR）。链格孢属是一种著名的土传病原体，可导致多种作物发生疫病。本研究通过诱导施用两种多能农药降解促植物生长根际细菌（PGPR），蜡样芽孢杆菌和安全芽孢杆菌，来研究小扁豆植株的防御反应，以减轻链格孢属的破坏作用。两种细菌菌株均通过土壤浇灌以不同的基于载体的生物制剂形式施用。我们评估了与链格孢属病原体的各种联合处理对防御相关酶的调节作用。使用气相色谱-质谱联用仪（GC-MS）分析抗菌化合物的体外产生，以确认其病原体抑制能力。田间试验表明，处理与产量和生长指数（GI）的改善之间存在正相关。在链格孢属存在的情况下，相对于对照，单独使用蜡样芽孢杆菌或与安全芽孢杆菌联合使用的处理中，观察到苯丙氨酸解氨酶（PAL）的酶诱导率最高（180%），其次是过氧化氢酶（CAT）（100%）和多酚氧化酶（PPO）（54%）。体外分析揭示了抗菌化合物的产生，包括苯甲酸衍生物、环四硅氧烷、二十六烷、毒死蜱和邻苯二甲酸盐，这可能有助于抑制病原体。我们的研究结果表明，这些生物防治剂（BCA）不仅刺激植物的酶防御系统，还能促进生长、提高种子产量并在体外产生几种抗菌化合物。因此，本研究中使用的耐农药PGPR兼具疾病控制和促进植物生长的特性，在可持续农业中具有广阔的应用前景。
