Foliar Application or Seed Priming of Cholic Acid-Glycine Conjugates can Mitigate/Prevent the Rice Bacterial Leaf Blight Disease via Activating Plant Defense Genes

Abstract

Xanthomonas Oryzae pv. oryzae (Xoo) causes bacterial blight and Rhizoctonia solani (R. solani) causes sheath blight in rice accounting for >75% of crop losses. Therefore, there is an urgent need to develop strategies for the mitigation of these pathogen infections. In this study, we report the antimicrobial efficacy of Cholic Acid-Glycine Conjugates (CAGCs) against Xoo and R. solani. We show that CAGC C6 is a broad-spectrum antimicrobial and is also able to degrade biofilms. The application of C6 did not hamper plant growth and showed minimal effect on the plant cell membranes. Exogenous application of C6 on pre-infection or post-infection of Xoo on rice susceptible genotype Taichung native (TN1) can mitigate the bacterial load and improve resistance through upregulation of plant defense genes. We further demonstrate that C6 can induce plant defense responses when seeds were primed with C6 CAGC. Therefore, this study demonstrates the potential of CAGCs as effective antimicrobials for crop protection that can be further explored for field applications.

Priming seeds for the future: Plant immune memory and application in crop protection

“…Chitosan-primed sugar beet plants exhibited upregulation of PR3, PAL, and GST genes, as well as enhanced resistance against CLS disease (Kappel et al, 2022). Rice primed with CAGCs induced expression of defense genes EDS1, ICS1, NPR1, MKK4, and PR1 genes, and enhanced resistance against rice bacterial leaf blight disease (Pal et al, 2021). Notably, INA-primed common bean plants and their stress-free offsprings exhibited epigenetic changes such as enrichment of H3K4me3 and H3K36me3, as well as low nucleosome occupancy at PvPR1 gene (Martínez-Aguilar et al, 2021).…”

“…Seed priming could secure the enhanced and uniformed seed germination and seedling establishment under field conditions, and greatly contributes to the improvement of crop growth and production (Marthandan et al, 2020;Johnson and Puthur, 2021). Increasing evidence revealed that seed priming could induce plant immune memory that is either stably maintained throughout developmental stages or transmitted over generations (Jogaiah et al, 2020;Joshi et al, 2021;Martínez-Aguilar et al, 2021;Pal et al, 2021;Yadav et al, 2021;Kappel et al, 2022). As summarized in Table 1, different types of seed priming approaches such as biological priming, chemical priming, and nanomaterials priming have been successfully established to protect crop plants against pathogen infections.…”

“…Defense priming requires immune memory to store the changes or information acquired from the initial pathogen perception, and retrieves this information upon a later pathogen challenge (Ramirez-Prado et al, 2018). As an environmental-friendly, pre-sowing enhancement technique, seed priming could effectively induce plant immune memory and have a great potential in sustainable crop protection (Jogaiah et al, 2020;Joshi et al, 2021;Martínez-Aguilar et al, 2021;Pal et al, 2021;Yadav et al, 2021;Kappel et al, 2022). Herein, we summarized recent development on the establishment and maintenance mechanisms of plant defense priming and the immune memory associated.…”

N-methyl Benzimidazole Tethered Cholic Acid Amphiphiles Can Eradicate S. aureus-Mediated Biofilms and Wound Infections

“…Among them, hexyl conjugated amphiphiles showed potent antimicrobial activity against Gram-positive, Gram-negative, and fungal pathogens [ 28 , 29 , 30 ]. Moreover, this amphiphile can be used to control Xoo infections in rice plants [ 31 ]. Apart from this, we also designed and synthesized cholic acid peptide conjugates (CAPs) where twenty different natural amino acids were tethered to three hydroxyl groups of benzylated CA via glycine linker.…”

Transcriptomic responses under combined bacterial blight and drought stress in rice reveal potential genes to improve multi-stress tolerance

“…TFs regulate many downstream target genes [ 28 – 32 ]. WRKY45 showed broad spectrum resistance and acts as a negative regulator for pathogen, salt, cold and drought stress is upregulated in combined stress [ 33 , 34 ]. WRKY11 acts as a positive regulator of defence response against Xoo and drought tolerance is upregulated in combined stress [ 35 ].…”