title: Tissue-specific expression of Arabidopsis NPR1 gene in rice for sheath blight resistance without compromising phenotypic cost.
abstract: Rice sheath blight disease, caused by the fungus Rhizoctonia solani, is considered the second most important disease of rice after blast. NPR1 (non expressor of PR1) is the central regulator of systemic acquired resistance (SAR) conferring broad spectrum resistance to various pathogens. Previous reports have indicated that constitutive expression of the Arabidopsis thaliana NPR1 (AtNPR1) gene results in disease resistance in rice but has a negative impact on growth and agronomic traits. Here, we report that green tissue-specific expression of AtNPR1 in rice confers resistance to the sheath blight pathogen, with no concomitant abnormalities in plant growth and yield parameters. Elevated levels of NPR1 activated the defence pathway in the transgenic plants by inducing expression of endogenous genes such as PR1b, RC24, and PR10A. Enhanced sheath blight resistance of the transgenic plants was evaluated using three different bioassay systems. A partially isolated toxin from R. solani was used in the bioassays to measure the resistance level. Studies of the phenotype and yield showed that the transgenic plants did not exhibit any kind of phenotypic imbalances. Our results demonstrate that green tissue-specific expression of AtNPR1 is an effective strategy for controlling the sheath blight pathogen. The present work in rice can be extended to other crop plants severely damaged by the pathogen.
authors.affiliation: Laboratory of Translational Research on Transgenic Crops, Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700019, West Bengal, India; Crop Improvement Division, ICAR-National Rice Research Institute, Cuttack 753006, Odisha, India.
authors.forename: Kutubuddin Ali
authors.initials: KA
authors.lastname: Molla
authors.affiliation: Laboratory of Translational Research on Transgenic Crops, Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700019, West Bengal, India.
authors.forename: Subhasis
authors.initials: S
authors.lastname: Karmakar
authors.affiliation: Laboratory of Translational Research on Transgenic Crops, Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700019, West Bengal, India; Center for Diabetes Research, The Methodist Hospital Research Institute, 6670 Bertner, Houston, TX 77030, USA.
authors.forename: Palas Kumar
authors.initials: PK
authors.lastname: Chanda
authors.affiliation: Laboratory of Translational Research on Transgenic Crops, Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700019, West Bengal, India.
authors.forename: Sailendra Nath
authors.initials: SN
authors.lastname: Sarkar
authors.affiliation: Laboratory of Translational Research on Transgenic Crops, Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700019, West Bengal, India; Visva Bharati University, Santiniketan, India.
authors.forename: Swapan Kumar
authors.initials: SK
authors.lastname: Datta
authors.affiliation: Laboratory of Translational Research on Transgenic Crops, Department of Botany, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700019, West Bengal, India. Electronic address: krbdatta@yahoo.com.
authors.forename: Karabi
authors.initials: K
authors.lastname: Datta
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D060467:Disease Resistance; D018506:Gene Expression Regulation, Plant; D009928:Organ Specificity; D012275:Oryza / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology; D045332:Photosystem II Protein Complex / Q000235:genetics* / Q000378:metabolism; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D057865:Plant Immunity; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D012232:Rhizoctonia / Q000502:physiology*; D017422:Sequence Analysis, DNA
chemical_list: D029681:Arabidopsis Proteins; C105496:NPR1 protein, Arabidopsis; D045332:Photosystem II Protein Complex
keywords: Disease management; Green tissue-specific promoter; Pathogenesis-related genes; Systemic acquired resistance; Transgenic rice; Yield penalty