Rhizosphere fungus Penicillium chrysogenum promotes growth and induces defence-related genes and downy mildew disease resistance in pearl millet

Murali, M. and Sudisha, J. and Amruthesh, K. N. and Ito, S. I. and Shetty, H. S. (2013) Rhizosphere fungus Penicillium chrysogenum promotes growth and induces defence-related genes and downy mildew disease resistance in pearl millet. Plant Biology, 15 (1). pp. 111-118.

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Official URL: https://doi.org/10.1111/j.1438-8677.2012.00617.x

Abstract

Susceptible pearl millet seeds (cv 7042S) were treated with the plant growth promoting fungus Penicillium chrysogenum (PenC-JSB9) at 1 x 10(8) spores center dot ml(-1) to examine mRNA expression profiles of five defence responsive genes and test its ability to induce resistance to downy mildew caused by Sclerospora graminicola. PenC-JSB9 treatment at 1 x 10(8) CFU center dot ml(-1) for 6 h significantly enhanced seed germination (9.8 89%), root length (4.08% to 5.1 cm), shoot length (18.9% to 7.77 cm) and reduced disease incidence (28%) in comparison with untreated controls. In planta colonisation of PenC-JSB9 showed that all three root segments (06 cm) and soil dilutions incubated on PDA produced extensive mycelial growth, however colonisation frequency of PenC-JSB9 was significantly higher in soil than in root segments. Spatiotemporal studies revealed that induction of resistance was triggered as early as 24 h and a minimum 23 days was optimal for total resistance to build up between inducer treatment and challenge inoculation in both experiments. In Northern blot analysis, transcript accumulation of resistant and PenC-JSB9 induced susceptible cultivars showed higher basal levels of defence gene expression than non-pretreated susceptible controls. Transcript accumulation in resistant seedlings challenge-inoculated with the pathogen showed maximum expression of CHS (3.5-fold increase) and Pr-1a (threefold increase) at 24 and 12 h, respectively. While PenC-JSB9 pretreated susceptible seedlings challenge-inoculated showed rapid and enhanced expression of LOX and POX at 48 h and for CHT at 24 h, whereas non-pretreated susceptible seedlings after pathogen inoculation showed weak expression of hybridised defence genes. Enhanced activation of defence genes by PenC-JSB9 suggests its role in elevated resistance against S. graminicola.

Item Type: Article
Uncontrolled Keywords: Induction of resistance; Penicillium chrysogenum; Sclerospora graminicola
Subjects: B Life Science > Biotechnology
B Life Science > Botany
Divisions: Department of > Biotechnology
Department of > Botany
Depositing User: Arshiya Kousar
Date Deposited: 12 Dec 2019 06:07
Last Modified: 12 Dec 2019 06:07
URI: http://eprints.uni-mysore.ac.in/id/eprint/10185

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