Submitted to: Advanced Studies in Biology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/11/2010
Publication Date: 4/15/2011
Citation: Kuykendall, L.D., Burdekin, K.A., Shao, J.Y., Conway, L.B. 2011. A plant gene encodes a 'HSFA9-like' heat shock factor and is part of a cluster of orthologous genes including NPR1, CaMP and CK1 in Beta vulgaris, Populus trichocarpa, Solanum lycopersicum and Vitis vinifera. Advanced Studies in Biology. 3(1):13-24. Interpretive Summary: Knowledge is the key to devising effective new strategies of controlling plant diseases, to enhance profitability and sustainability of crop production. Information on many genes that control pathogen defense, development or stress tolerance is generally lacking for some important crop plants. In this study, a gene common to grape, sugarbeet, tomato and poplar was found to be the next-door neighbor of a particular gene critical for resistance to disease-forming microbes. The gene, called “HSFA,” encodes a protein that is a regulator of gene expression. Proximity of genes may reflect coordinated expression since the products of both neighbor genes control gene expression in the nucleus of cells. Bioinformatics was used to categorize and better understand the protein product compared with proteins encoded by similar genes in sunflower and the model plant species Arabidopsis thaliana, for example. The molecular biological properties of such specifically important plant genes can be used by scientists to help devise strategies for improving disease resistance.
Technical Abstract: Very closely physically linked within about 1 Kb and 2 Kb in sugarbeet and poplar, respectively, HSF and NPR1 genes exhibit opposing directions of transcription. Predicted proteins encoded by poplar, sugarbeet, grape, and tomato NPR1-adjacent, orthologous HSF genes all share significant amino acid sequence similarity to a protein encoded by gene HSFA9. In sunflower (Helianthus annuus) this gene is embryonically expressed in where it controls leaf pattern development. The similarity group contains a predicted product encoded by HSFA9 of Arabidopsis thaliana when compared with diverse HSFs of type A (15 in Arabidopsis), type B (5 in Arabidopsis) and type C (only 1 in Arabidopsis). Structurally related proteins, however, also include HSFA2 of Arabidopsis thaliana and HSF30 of Solanum peruvianum. Taken together with the lack of BlastN hits in the poplar and sugarbeet EST databases, the amino acid sequence similarity of the predicted protein products of “HSFA9-like,” NPR1-adjacent, HSFA genes indicates that these genes may only be conditionally and/or developmentally expressed. An EST match was found in ripening fruit of tomato.