Microbial modulation of bacoside A biosynthetic pathway and systemic defense mechanism in Bacopa monnieri under Meloidogyne incognita stress.
Plant-associated beneficial microbes have been explored to fulfill the imperative function for plant health. However, their impact on the host secondary metabolite production and nematode disease management remains elusive. Our present work has shown that chitinolytic microbes viz., Chitiniphilus sp. MTN22 and Streptomyces sp. MTN14 singly as well as in combination modulated the biosynthetic pathway of bacoside A and systemic defense mechanism against Meloidogyne incognita in Bacopa monnieri. Interestingly, expression of bacoside biosynthetic pathway genes (3-Hydroxy-3-methylglutaryl coenzyme A reductase, mevalonate diphosphate decarboxylase, and squalene synthase) were upregulated in plants treated with the microbial combination in the presence as well as in absence of M. incognita stress. These microbes not only augmented bacoside A production (1.5 fold) but also strengthened host resistance via enhancement in chlorophyll a, defense enzymes and phenolic compounds like gallic acid, syringic acid, ferulic acid and cinnamic acid. Furthermore, elevated lignification and callose deposition in the microbial combination treated plants corroborate well with the above findings. Overall, the results provide novel insights into the underlying mechanisms of priming by beneficial microbes and underscore their capacity to trigger bacoside A production in B. monnieri under biotic stress.
Department of Microbial Technology and Nematology, CSIR- Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP, Lucknow 226015, India.|Academy of Scientific and Innovative Research, CSIR- Central Institute of Medicinal and Aromatic Plants Campus, Lucknow 226015, Uttar Pradesh, India.
Rupali
R
Gupta
Department of Microbial Technology and Nematology, CSIR- Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP, Lucknow 226015, India.
Akanksha
A
Singh
Department of Analytical Chemistry, CSIR- Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP, Lucknow 226015, India.
Madhumita
M
Srivastava
Department of Botany, Faculty of Science, Banaras Hindu University, Varanasi, 221005, India.
Vivek
V
Singh
Department of Analytical Chemistry, CSIR- Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP, Lucknow 226015, India.
M M
MM
Gupta
Department of Microbial Technology and Nematology, CSIR- Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP, Lucknow 226015, India.
Rakesh
R
Pandey
D000818:Animals; D034681:Bacopa / Q000276:immunology / Q000378:metabolism / Q000382:microbiology*; D002262:Carboxy-Lyases / Q000235:genetics / Q000378:metabolism; D013186:Farnesyl-Diphosphate Farnesyltransferase / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D054884:Host-Pathogen Interactions; D025782:Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent / Q000235:genetics / Q000378:metabolism; D057865:Plant Immunity; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012503:Saponins / Q000096:biosynthesis*; D013302:Streptomyces / Q000472:pathogenicity; D013312:Stress, Physiological; D014315:Triterpenes; D014431:Tylenchoidea / Q000472:pathogenicity*; D015854:Up-Regulation
D010940:Plant Proteins; D012503:Saponins; D014315:Triterpenes; C500175:bacoside A; D025782:Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent; D013186:Farnesyl-Diphosphate Farnesyltransferase; D002262:Carboxy-Lyases; C022503:pyrophosphomevalonate decarboxylase