Bio-Priming of Tissue Culture Raised Decalepis arayalpathra (J. Joseph & V. Chandras.) Venter, KMA 05 Clones with the Phyllospheric Bacterium, Methylobacterium sp.VP103 and its Biocontrol Potential
Srivastava Shikha, Laisram Nellie, Ram Hari, Singh Ved Pal*
Applied Microbiology and Biotechnology Laboratory Department of Botany, University of Delhi, Delhi-110 007, India
*Corresponding author: Ved Pal Singh, Applied Microbiology and Biotechnology Laboratory Department of Botany, University of Delhi, India, Email: firstname.lastname@example.org
Decalepis arayalpathra (J. Joseph & V. Chandras.) Venter, which belongs to the family Apocynaceae popularly known as ‘Amruthpala’ by the native Kani tribe is a lithophytic, woody, laticiferous undershrub. The rapid pace of deforestation inthe Western Ghats has decreased the number of Decalepis arayalpathra. Vegetative propagation and natural regeneration inthis plant is also very difficult because of poor fruit set, seed germination and rooting on stem cuttings. Hence, it has been enlisted as a critically endangered species. As a step towards conservation, an improved and successful protocol for in vitro establishment and clonal propagation of Decalepis arayalpathra viz. Amruthpala was attempted at CIMAP- Lucknow. For effective root induction and greenhouse establishment of the plantlets, further studies on this plant was conducted with a phyllospheric bacterium Methylobacterium sp. VP103 which was isolated fromthe leaves of greenhouse/field established Decalepis arayalpathra KMA 05 clones and identified using 16S rRNA gene sequence analysis. The identified bacterium Methylobacterium sp. VP103 showed maximum pairwise similarity with Methylobacterium aminovorans. All shoot tip explants, when inoculated withthis bacterium, produced greener and broader leaves as well assturdier roots as compared to the control. The chemical profilingof the metabolites of this bacterium was also done through Gaschromatography-Mass spectrometry (GC-MS). The compoundpresent with maximum area was an antibacterial compound Pyrrolo[1, 2-a] pyrazine-1, 4-dione, hexahydro-3-(2-methylpropyl). Another compound, 2,5-Piperazinedione, 3,6-bis (phenyl methyl)which is reported as an antifungal compound was also observed. The compound, 1H-Purine-6-Amine, [(2-Fluorophenyl) Methyl]which is also known to play a good role in cell division and plant growth was also present. Thus, the role of this bacterium hasbeen established as a potential biocontrol agent in promoting the growth of the plant and its survival in field conditions.