Decoyinine Induced Resistance in Rice against Small Brown Planthopper Laodelphax striatellus

Abstract

Induced resistance against SBPH via microbial pesticides is considered as an eco-friendly and promising management approach. In this study, the induced resistance against SBPH in rice seedling by a new potential microbial pesticide, decoyinine (DCY), a secondary metabolite produced by Streptomyces hygroscopicus, was evaluated to investigate the effects of DCY on SBPH’s biological and population parameters along with defense-related physiological and biochemical indices in rice against SBPH feeding. We found that DCY has potential to improve rice resistance and significantly reduced the fecundity of SBPH. Laboratory results revealed that DCY treated rice significantly changed SBPH’s fecundity and population life table parameters. The concentrations of hydrogen peroxide (H2O2), soluble sugars and malondialdehyde (MDA) were significantly lower in DCY treated rice plants against SBPH infestation at 24, 48 and 96 hours post infestation (hpi), respectively. The concentrations of antioxidant enzymes, catalase (CAT) was significantly higher at 72 hpi, while super oxidase dismutase (SOD) and peroxidase (POD) concentrations were recorded higher at 96 hpi. The concentrations of synthases enzymes, phenyl alanine ammonia-lyase (PAL) was higher at 48 hpi, whereas polyphenol oxidase (PPO) concentration was maximum at 72 hpi against SBPH infestation. The results imply that DCY has unique properties to enhance rice resistance against SBPH by stimulating plant defensive responses. Microbial pesticides may be developed as an alternative to chemical pest control.

Development and Application of the Novel Plant Growth Regulator Guvermectin: A Perspective

“…Recently, a growing body of evidence has suggested that GV also fortifies plants against pest damage (Figure ). Priming rice seeds with GV has been found to enhance resistance to brown planthopper (BPH, Nilaparvata lugens) and small brown planthopper (SBPH, Laodelphax striatellus) by significantly reducing their fertility. − Physio-biochemical analyses indicate that when GV-treated rice was fed upon by BPH, there was an enhancement in the activities of plant defense-related enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione S transferase (GST), peroxidase (POD), and polyphenol oxidase (PPO) . Additionally, transcriptomic analyses showed that these feeding events precede the upregulation of 15 resistance-related WRKY genes.…”

Versatile Roles of Microbes and Small RNAs in Rice and Planthopper Interactions

“…An earlier study indicated that treating rice seedlings by root drenching with Bacillus velezensis YC7010, an endophytic strain, induced systemic resistance against BPH ( Harun-Or-Rashid et al, 2018 ). Another study reported the efficiency of decoyinine, a metabolite derived from the endophytic Streptomyces hygroscopicus in triggering induced systemic resistance in rice against the SBPH, L. striatellus and indirectly affect the fecundity and population life table parameters ( Shah et al, 2022 ).…”

Characterizing the Mechanism of Serotonin Alleviates Rice Resistance to Brown Planthopper Nilaparvata lugens (Homoptera: Delphacidae) Nymphs

“…Previous studies have shown that antioxidant enzymes, such as POD, SOD, CAT, and PPO, are involved in plant defense [31,32], therefore, we tested the activities of POD, SOD, CAT, and PPO after exogenously application of various concentrations of serotonin. The POD activities were significantly higher in serotonin-treated rice plants, reaching highest activities at concentrations of 50 and 100 µM, compared to control plants (Figure 7A).…”

“…Previous studies have demonstrated that nutrient constituents, such as soluble sugars and free amino acids, are important indexes of host plant quality and are associated with BPH-induced rice defense [29,30]. In addition, the role of flavonoids, and defensive proteins including peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), and polyphenol oxidase (PPO) in regulating rice resistance to BPH has also been well documented [31][32][33][34].…”