title: Visual Analysis for Detection and Quantification of Pseudomonas cichorii Disease Severity in Tomato Plants.
abstract: Pathogen infection in plants induces complex responses ranging from gene expression to metabolic processes in infected plants. In spite of many studies on biotic stress-related changes in host plants, little is known about the metabolic and phenotypic responses of the host plants to Pseudomonas cichorii infection based on image-based analysis. To investigate alterations in tomato plants according to disease severity, we inoculated plants with different cell densities of P. cichorii using dipping and syringe infiltration methods. High-dose inocula (≥ 10(6) cfu/ml) induced evident necrotic lesions within one day that corresponded to bacterial growth in the infected tissues. Among the chlorophyll fluorescence parameters analyzed, changes in quantum yield of PSII (ΦPSII) and non-photochemical quenching (NPQ) preceded the appearance of visible symptoms, but maximum quantum efficiency of PSII (Fv/Fm) was altered well after symptom development. Visible/near infrared and chlorophyll fluorescence hyperspectral images detected changes before symptom appearance at low-density inoculation. The results of this study indicate that the P. cichorii infection severity can be detected by chlorophyll fluorescence assay and hyperspectral images prior to the onset of visible symptoms, indicating the feasibility of early detection of diseases. However, to detect disease development by hyperspectral imaging, more detailed protocols and analyses are necessary. Taken together, change in chlorophyll fluorescence is a good parameter for early detection of P. cichorii infection in tomato plants. In addition, image-based visualization of infection severity before visual damage appearance will contribute to effective management of plant diseases.
authors: Division of Biotechnology, Chonbuk National University, Iksan 54596, Korea.
authors: Dhinesh Kumar
authors: DK
authors: Rajendran
authors: Department of Biosystems Machinery Engineering, Chungnam National University, Daejeon 34134, Korea.
authors: Eunsoo
authors: E
authors: Park
authors: Division of Biotechnology, Chonbuk National University, Iksan 54596, Korea.
authors: Rajalingam
authors: R
authors: Nagendran
authors: Division of Biotechnology, Chonbuk National University, Iksan 54596, Korea.
authors: Nguyen Bao
authors: NB
authors: Hung
authors: Department of Biosystems Machinery Engineering, Chungnam National University, Daejeon 34134, Korea.
authors: Byoung-Kwan
authors: BK
authors: Cho
authors: Molecular Breeding Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Korea.
authors: Kyung-Hwan
authors: KH
authors: Kim
authors: Division of Biotechnology, Chonbuk National University, Iksan 54596, Korea; Advanced Institute of Environment & Bioscience and Plant Medical Research Center, Chonbuk National University, Iksan 54596, Korea.
authors: Yong Hoon
authors: YH
authors: Lee
keywords: chlorophyll fluorescence; detection; hyperspectral image; phenome