Developmental regulation of Mi-mediated aphid resistance is independent of Mi-1.2 transcript levels
Fiona L Goggin1, Gowri Shah, Valerie M Williamson
1Department of Entomology, University of Arkansas, 320 Agriculture Building, Fayetteville 72701, USA. fgoggin@uark.edu
Abstract:
Mi-1.2, a member of the intracellular, nucleotide-binding site-leucine-rich repeat family of resistance genes, confers resistance in tomato (Lycopersicon esculentum) against both root-feeding nematodes and leaf-feeding aphids. Nematode resistance is effective in all life stages of the plant; in contrast, Mi-mediated aphid resistance is developmentally regulated, and protects mature plants but not seedlings against aphid infestation. To determine if the onset of aphid resistance is regulated by Mi-1.2 transcript abundance, we compared aphid resistance and Mi-1.2 transcript levels in seedlings and flowering plants. Paired bioassays and RNase protection assays revealed that Mi-1.2 is transcribed in the leaves prior to the onset of aphid resistance, and that transcript levels are comparable in seedlings and flowering life stages. Furthermore, constitutive overexpression of Mi-1.2 in transgenic plants did not hasten the onset of aphid resistance in seedlings, or boost the level of resistance observed in flowering plants. These data demonstrate that Mi-1.2 transcript levels do not modulate the degree of aphid resistance in tomato leaves, or control the differences in regulation between aphid and nematode resistance.
Related Concept Videos
Epigenetic Regulation
Regulation of Expression Occurs at Multiple Steps
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Regulation of Expression Occurs at Multiple Steps
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Epigenetic Regulation
X-chromosome...
Regulation of Expression at Multiple Steps
Repressible Operon: trp Operon


