Molecular mechanism of plant growth promotion and induced systemic resistance to tobacco mosaic virus by Bacillus spp.
Bacillus spp., as a type of plant growth-promoting rhizobacteria (PGPR), were studied with regards promoting plant growth and inducing plant systemic resistance. The results of greenhouse experiments with tobacco plants demonstrated that treatment with the Bacillus spp. significantly enhanced the plant height and fresh weight, while clearly lowering the disease severity rating of the tobacco mosaic virus (TMV) at 28 days post-inoculation (dpi). The TMV accumulation in the young non-inoculated leaves was remarkably lower for all the plants treated with the Bacillus spp. An RTPCR analysis of the signaling regulatory genes Coi1 and NPR1, and defense genes PR-1a and PR-1b, in the tobacco treated with the Bacillus spp. revealed an association with enhancing the systemic resistance of tobacco to TMV. A further analysis of two expansin genes that regulate plant cell growth, NtEXP2 and NtEXP6, also verified a concomitant growth promotion in the roots and leaves of the tobacco responding to Bacillus spp.
Wang
Shuai
S
Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Agriculture, Nanjing 210095, P. R. China.
Wu
Huijun
H
Qiao
Junqing
J
Ma
Lingli
L
Liu
Jun
J
Xia
Yanfei
Y
Gao
Xuewen
X
D001407:Bacillus / Q000276:immunology* / Q000502:physiology; D007113:Immunity, Innate; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology / Q000821:virology*; D018515:Plant Leaves / Q000276:immunology / Q000382:microbiology / Q000821:virology; D018517:Plant Roots / Q000276:immunology / Q000382:microbiology / Q000821:virology; D014026:Nicotiana / Q000254:growth & development* / Q000276:immunology* / Q000382:microbiology / Q000821:virology; D014027:Tobacco Mosaic Virus / Q000502:physiology*