Endophytic Pseudomonas sp. TCA1 from Tinospora cordifolia Stem with Antagonistic and Plant growth-promoting Potential

摘要

Endophytes habitat plant tissue without causing any infections to plants, promoting plant growth and also act as defend mechanism from stressed condition of environment. An endophytic bacterium showing fluorescent green pigment while growing around Tinospora cardifolia stem tissue sample was screened for antagonistic activity against phytopathogenic fungi Fusarium moniliforme, Fusarium verticillioides, Curvularia lunata and Alternaria alternata. The isolate showed broad-spectrum antagonism against all test fungi. Microscopic examination of the co-cultures showed morphological alterations of fungal hyphae and spores in comparison to the fungal culture grown alone. The bacterial isolate was identified on the basis of 16S rRNA gene sequencing as Pseudomonas sp. The isolate also showed multiple plant growth-promoting activities of phosphate solubilization, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, and production of IAA-like auxins, siderophores, ammonia and hydrogen cyanide (HCN). The bacterial isolate significantly increased the shoot length, root length and dry weight of maize plants in comparison to uninoculted plants in pots under natural conditions. The studies revealed the potential of the endophytic Pseudomonas sp. strain TCA1 to be used as plant growth-promoting microbial inoculant for disease control in agriculture.