Division of Biopesticides and Environmental Toxicology, Sri Paramakalyani Centre for Excellence in Environmental Sciences, Manonmaniam Sundaranar University, Alwarkurichi, Tirunelveli, Tamil Nadu, 627 412, India.
Department of Biotechnology, St. Peter's Institute of Higher Education and Research, Avadi, Chennai, Tamil Nadu, 600 054, India.
Sci Rep. 2021 Oct 14;11(1):20488. doi: 10.1038/s41598-021-99391-w.
Reduced pathogen resistance and management of the left-over rice stubble are among the most important challenges faced in rice cultivation. A novel and eco-friendly strategy to synthesise 'Fungal Chitosan' (FC) from Aspergillus niger using rice straw could serve as a sustainable treatment approach to improve both disease resistance and yields, while also effectively managing the rice stubble waste. The FC treatment promoted germination as well as growth parameters in rice varieties, TN1 (high yielding-susceptible) and PTB33 (low yielding-resistant) better than a commercial chitosan (PC). Treatments of exogenously applied FC to plants produced direct toxicity to Xoo, and reduced the BLB disease index by 39.9% in TN1. The capability of FC to trigger a cascade of defense pathways was evident from the measurable changes in the kinetics of defense enzymes, peroxidase (POD) and polyphenol oxidase (PPO). FC treatment increased levels of POD in TN1 by 59.4%, which was 35.3% greater than that of untreated PTB33. Therefore, the study demonstrated the effectiveness of FC treatments for use in agriculture as a potential biostimulant as well as protective agent against bacterial leaf blight, BLB, of rice (Oryza sativa) that could be produced from stubble waste and improve rice stubble management strategies.
减少病原菌抗性和处理剩余稻茬是水稻种植中面临的最重要挑战之一。一种新颖且环保的策略是使用稻草从黑曲霉中合成“真菌壳聚糖”（FC），这可能是一种可持续的处理方法，可以提高抗病性和产量，同时有效处理稻茬废物。FC 处理促进了 TN1（高产量-易感）和 PTB33（低产量-抗性）两种水稻品种的发芽和生长参数，优于商业壳聚糖（PC）。将外源 FC 施用于植物会直接对 Xoo 产生毒性，并将 TN1 中的 BLB 疾病指数降低 39.9%。FC 触发防御途径级联的能力从防御酶（POD 和 PPO）动力学的可测量变化中显而易见。FC 处理使 TN1 中的 POD 水平增加了 59.4%，比未处理的 PTB33 高 35.3%。因此，该研究表明 FC 处理可有效用于农业，作为一种潜在的生物刺激素和保护性剂，可防治水稻细菌性条斑病（BLB），可由稻茬废物生产，并改善稻茬管理策略。
