Centre for Drug Discovery and Development, Dr.Col.Jeppiaar Research Park, Sathyabama Institute of Science and Technology, Tamil Nadu, Chennai, 600 119, India.
Department of Plant Pathology, Tamil Nadu Agricultural University (TNAU), Tamil Nadu, Coimbatore, 641 003, India.
Curr Microbiol. 2022 Mar 27;79(5):146. doi: 10.1007/s00284-022-02832-6.
Streptomyces strains were isolated from rhizosphere soil and evaluated for in vitro plant growth and antagonistic potential against Ralstonia solanacearum. Based on their in vitro screening, seven Streptomyces were evaluated for plant growth promotion (PGP) and biocontrol efficacy by in-planta and pot culture study. In the in-planta study, Streptomyces-treated eggplant seeds showed better germination percentage, plant growth, and disease occurrence against R. solanacearum than the control treatment. Hence, all seven Streptomyces cultures were developed as a bioformulation by farmyard manure and used for pot culture study. The highest plant growth, weight, and total chlorophyll content were observed in UP1A-1-treated eggplant followed by UP1A-4, UT4A-49, and UT6A-57. Similarly, the maximum biocontrol efficacy was observed in UP1A-1-treated eggplants against bacterial wilt. The biocontrol potential of Streptomyces is also confirmed through metabolic responses by assessing the activities of the defense-related enzymes peroxidase (POX), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) and as well as the levels of total phenol. Treatment with UP1A-1/ UT4A-49 and challenge with R. solanacearum led to maximum changes in the activities of POX, PPO, and PAL and the levels of total phenol in the eggplants at different time intervals. Alterations in enzymes of UP1A-1 treatment were related to early defense responses in eggplant. Therefore, the treatment with UP1A-1 significantly delayed the establishment of bacterial wilt in eggplant. Altogether, the present study suggested that the treatment of Streptomyces maritimus UP1A-1 fortified farmyard manure has improved the plant growth and stronger disease control against R. solanacearum on eggplant.
从根际土壤中分离出链霉菌菌株，并评估其对丁香假单胞菌的体外植物生长和拮抗潜力。基于其体外筛选，通过植物体内和盆栽培养研究评估了 7 株链霉菌对植物生长促进 (PGP) 和生防效果。在植物体内研究中，与对照处理相比，用链霉菌处理的茄子种子表现出更好的发芽率、植物生长和对丁香假单胞菌的发病情况。因此，所有 7 株链霉菌培养物均由农家肥开发为生物制剂，并用于盆栽培养研究。在 UP1A-1 处理的茄子中观察到最高的植物生长、重量和总叶绿素含量，其次是 UP1A-4、UT4A-49 和 UT6A-57。同样，在 UP1A-1 处理的茄子中观察到对细菌性萎蔫病的最大生防效果。通过评估防御相关酶过氧化物酶 (POX)、多酚氧化酶 (PPO) 和苯丙氨酸解氨酶 (PAL) 的活性以及总酚水平，也证实了链霉菌的生防潜力。用 UP1A-1/UT4A-49 处理并与丁香假单胞菌挑战导致茄子在不同时间间隔内 POX、PPO 和 PAL 的活性以及总酚水平发生最大变化。UP1A-1 处理中酶的变化与茄子的早期防御反应有关。因此，UP1A-1 的处理显著延迟了茄子细菌性萎蔫病的建立。总的来说，本研究表明，处理海洋链霉菌 UP1A-1 强化的农家肥提高了茄子的植物生长和对丁香假单胞菌更强的病害控制效果。
