Identification of a Chitooligosaccharide Mechanism against Bacterial Leaf Blight on Rice by In Vitro and In Silico Studies

Abstract

This study focuses on a commercial plant elicitor based on chitooligosaccharides (BIG®), which aids in rice plant growth and disease resistance to bacterial leaf blight (BLB). When the pathogen (Xoo) vigorously attacks rice that has suffered yield losses, it can cause damage in up to 20% of the plant. Furthermore, Xoo is a seed-borne pathogen that can survive in rice seeds for an extended period. In this study, when rice seeds were soaked and sprayed with BIG®, there was a significant increase in shoot and root length, as well as plant biomass. Furthermore, BIG®-treated rice plants showed a significant reduction in BLB severity of more than 33%. Synchrotron radiation-based Fourier transform infrared (SR-FTIR) analysis was used to characterize BIG®’s mechanism in the chemical structure of rice leaves. The SR-FTIR results at 1650, 1735, and 1114 cm−1 indicated changes in biochemical components such as pectins, lignins, proteins, and celluloses. These findings demonstrated that commercial BIG® not only increased rice growth but also induced resistance to BLB. The drug’s target enzyme, Xoo 1075 from Xanthomonas oryzae (PDB ID: 5CY8), was analyzed for its interactions with polymer ingredients, specifically chitooligosaccharides, to gain molecular insights down to the atomic level. The results are intriguing, with a strong binding of the chitooligosaccharide polymer with the drug target, revealing 10 hydrogen bonds between the protein and polymer. Overall, the computational analysis supported the experimentally demonstrated strong binding of chitooligosaccharides to the drug target.

Transcriptomic analysis of pea plant responses to chitooligosaccharides’ treatment revealed stimulation of mitogen-activated protein kinase cascade

“…Taken together, our results point to a rapid and significant activation of pea genes involved in regulation of host defense responses, induced by CO8-DA, in accordance with previous findings for chitin-related compounds in Arabidopsis , rice, potato, tea ( Chen et al., 2020 ; Lemke et al., 2020 ; Siriwong et al., 2021 ; Ichimaru et al., 2022 ; Ou et al., 2022 ). We have shown that a set of genes encoding specific enzymes involved in the biosynthesis of phytoalexins and other secondary metabolites was up-regulated in response to CO8-DA, that was in line with previous findings in other plants ( Vasyukova et al., 2001 ; Khan et al., 2003 ; Zhang et al., 2020 ).…”

“…The pea plant treatment with CO8-DA stimulated the synthesis of such components as lignins, reinforcing the cell wall. Similar effect of COs was previously shown in rice and tea ( Siriwong et al., 2021 ; Ou et al., 2022 ).…”

Evaluating the structural and immune mechanism of Interleukin-6 for the investigation of goat milk peptides as potential treatments for COVID-19

“…The final conformations are subject to refinement using the firedock protocol. The pose matching in common between the HpepDock server and Patchdock server is subject to redocking with SP docking in Glide for the purpose of scoring and correctness of bonding/binding information's (Siriwong et al, 2021;Tubert-Brohman et al, 2013).…”

Effect of plant growth regulators DA-6 and COS on drought tolerance of pineapple through bromelain and oxidative stress

“…COSs, the oligomers of chitosan, are a non-toxic, efficient, novel antioxidants that act as signal molecules as well as chemical agents against abiotic stress [ 28 ]. In recent studies, COSs have been shown to have a certain degree of antifungal and antioxidant properties as well [ 29 – 32 ]. Specifically, COSs have been found to improve the growth and photosynthetic characteristics of wheat seedlings [ 33 ] and have a positive effect on the thermotolerance of arabidopsis [ 34 ].…”