Authors: Hong Luo JangYong Lee Qian Hu Kimberly NelsonVasilchik Timothy K Eitas Colin Lickwar Albert P Kausch Joel M Chandlee Thomas K Hodges
Publish Date: 2006/08/01
Volume: 62, Issue: 3, Pages: 397-408
Abstract
A tapetumspecific gene RTS has been isolated by differential screening of a cDNA library from rice panicles RTS is a unique gene in the rice genome RNA blot analysis and in situ hybridization indicates that this gene is predominantly expressed in the anther’s tapetum during meiosis and disappears before anthesis RTS has no introns and encodes a putative polypeptide of 94 amino acids with a hydrophobic Nterminal region The nucleotide and deduced amino acid sequence of the gene do not show significant homology to any known sequences However a sequence in the promoter region GAATTTGTTA differs only by one or two nucleotides from one of the conserved motifs in the promoter region of two pollenspecific genes of tomato Several other sequence motifs found in other antherspecific promoters were also identified in the promoter of the RTS gene Transgenic and antisense RNA approaches revealed that RTS gene is required for male fertility in rice The promoter region of RTS when fused to the Bacillus amyloliquefaciens ribonuclease gene barnase or the antisense of the RTS gene is able to drive tissuespecific expression of both genes in rice creeping bentgrass Agrostis stolonifera L and Arabidopsis conferring male sterility to the transgenic plants Light and nearinfrared confocal microscopy of crosssections through developing flowers of malesterile transgenics shows that tissuespecific expression of barnase or the antisense RTS genes interrupts tapetal development resulting in deformed nonviable pollen These results demonstrate a critical role of the RTS gene in pollen development in rice and the versatile application of the RTS gene promoter in directing antherspecific gene expression in both monocotyledonous and dicotyledonous plants pointing to a potential for exploiting this gene and its promoter for engineering male sterility for hybrid production of various plant speciesThis work was supported by grants from the Rockefeller foundation to Purdue University TKH and in part by the USDASBIR Grants 20033361013107 20053361015620 to HybriGene Inc HL and by the USDABRAG grant 20053945416511 to Clemson University HL Technical Contribution No 5214 of the Clemson University Experiment Station
Keywords: