Biomolecule repository of endophytic bacteria from guava serves as a key player in suppressing root- knot nematode, Meloidogyne enterolobii

• Published in: Scientia horticulturae 2024-01, Vol.324, p.112627, Article 112627
• Main Authors: Ganeshan, Shandeep, Annaiyan, Shanthi, Somasundaram, Prabhu, Mannu, Jayakanthan, Kathithachalam, Angappan, Shanmugam, Haripriya, Arunachalam, Arun
• Format: Article
• Language: English
• Subjects: amino acids; bacteria; benzoic acid; Biological control; chlorides; egg masses; eggs; endophytes; guavas; hexokinase; India; Klebsiella; Meloidogyne enterolobii; Mode of action; Molecular modelling and docking; Nematicidal activity; nematicides; neoplasms; pectate lyase; phospholipases; plant growth; Plant parasitic nematodes; root-knot nematodes; soil; translation (genetics)
• ISSN: 0304-4238; 1879-1018
• DOI: 10.1016/j.scienta.2023.112627

•The endomicrobiome of Guava plants confers resistance against guava root knot nematodes, Meloidogyne enterolobii.•The endophytic bacterial community tends to produce various bioactive molecules which plays key role in suppression of nematodes.•Molecular docking studies proved that the bacterial biomolecules benzoic acid, 4-Cyanophenyl 4-butylbenzoate, Trifluoroacetophenone, 6,12-dinaphthylindolo[3,2-b]carbazole, 3-phenyl-1,2,4-triazolin-5-one had predominant effect over protein targets of M. enterolobii.•The greenhouse studies revealed that these bacterium not only supressed the soil and root population of nematodes but also triggered the plant growth parameters of guava. Guava production in India is hampered by invasion of guava root knot nematode, Meloidogyne enterolobii. Biological control of plant parasitic nematodes is the best strategy to quench the soil and root population of nematodes. Hence the attempts were made to dissect the endophytic bacteria from various niche of guava plants. Amongst the various endophytic bacteria's, Klebsiella quasivaricola inhibited the egg hatching (100%) and moratlity of juveniles (100%). Exploration of non-volatile organic compounds of K. quasivaricola exhibited the presence of 2″-terthiophene, 9′spirobifluorenone, 4-Cyanophenyl 4-butylbenzoate, Benzoic acid, Benzoyl chloride, 3-phenyl-1, 2, 4-triazolin-5-one, Ethanone, 2,3-dihydro-5‑methoxy-, Ethanone, Trifluoroacetophenone, 6,12-dinaphthylindolo[3,2-b] carbazole having anti-microbial activities. Considering this, molecular docking experiments were carried out with important proteins of M. enterolobii such as Translationally Controlled Tumour Proteins, pectate lyase, phospholipase, hexokinase and Sphingomyelinase to understand the effect of biomolecules from K. quasivaricola. The results indicated that all biomolecules had prominent effect on different protein targets and in specific binding affinity with amino acid residues of protein targets benzoic acid, 4-Cyanophenyl 4-butylbenzoate, Trifluoroacetophenone, 6,12-dinaphthylindolo[3,2-b]carbazole, 3-phenyl-1,2,4-triazolin-5-one had significant effect on aforementioned protein targets of M. enterolobii. In addition, bio-hardened guava plants with the effective bacterial endophytes were challenged with M. enterolobii showcased 80% increase on plant growth parameters and 70% reduction of egg mass over control. Hence the present study gave limelight to explore the novel biomolecules from endophytic bacterium which coul