Anther-specific expression of mutated melon ethylene receptor gene Cm-ERS1/H70A affected tapetum degeneration and pollen grain production in transgenic tobacco plants.
ABSTRACT To develop a new system for inducible male sterility without any modification of the floral architecture in tobacco plants, a mutated ethylene receptor gene Cm-ERS1/H70A was fused either to the tobacco Nin88 promoter known to function mainly in the tapetum and microspore or to the CaMV 35S promoter known to be a constitutive promoter. The fusion genes pNin88::Cm-ERS1/H70A and p35S::Cm-ERS1/H70A were introduced in tobacco plants, which generated two independent transformants. Transformants with 35S::Cm-ERS1/H70A produced less normal pollen and had modified floral architecture while those with Nin88::Cm-ERS1/H70A produced less normal pollen without modification of floral architecture. Histological observations of anthers at stage 2 showed that tapetum degeneration in NH70A #8 and H70A #2 transformants occurred later than in wild types, strongly indicating that the expression of the mutated gene was involved in this delay. These results suggest that the tapetum-specific expression of a mutated ethylene receptor gene is a potential strategy for inducing male sterility in transgenic plants.
Article: Engineered Male Sterility[Show abstract] [Hide abstract]
ABSTRACT: The agricultural exploitation of hybrid crop varieties has enabled enormous increases in food productivity through increased uniformity and hybrid vigour. Because of hybrid vigour, or heterosis , these crops are characterized by an increased resistance to disease and enhanced performance in different environments when comparing the heterozygous hybrid progeny (called F1 hybrids) to the homozygous parents. The generation of male sterility, mainly nucleus -encoded, is the basis of new, reliable, and cost-effective pollination control systems for genetic engineering that have been developed during the past decade. The propagation of male-sterile female parent lines is an important aspect for the successful application of these systems in large-scale hybrid seed production. This article describes the development and use of transgenic engineered plants.01/2010;
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ABSTRACT: Cytoplasmic male sterility (CMS)-C is one of the most attractive sources of male sterility in the production of hybrid maize. However, the abortion mechanism of CMS-C is currently unknown. The major aim of this work was to characterize the expression of genes and proteins during pollen abortion. The materials assayed included CMS-C line C48-2, its maintainer line N48-2, and fertile F(1) (C48-2 × 18 white). A total of 20 unique genes and 25 proteins were identified by suppression subtractive hybridization and 2-D electrophoresis, respectively. Most of the genes and proteins identified are closely related to energy metabolism, stress responses, molecular chaperones, and cell death, which are generally considered to be essential to pollen development. Based on the function of these identified genes and proteins, reactive oxygen species in isolated mitochondria and DNA fragments were analyzed. The results from this study indicate that the oxidative stress which was associated with the specific expression patterns of some genes may be the physiological cause for the abortion of premature microspores in the maize CMS-C line.Protoplasma 12/2011; 249(4):1119-27. · 2.86 Impact Factor
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ABSTRACT: The past two decades have been rewarding in terms of deciphering the ethylene signal transduction and functional validation of the ethylene receptor and downstream genes involved in the cascade. Our knowledge of ethylene receptors and its signal transduction pathway provides us a robust platform where we can think of manipulating and regulating ethylene sensitivity by the use of genetic engineering and making transgenic. This review focuses on ethylene perception, receptor mediated regulation of ethylene biosynthesis, role of ethylene receptors in flower senescence, fruit ripening and other effects induced by ethylene. The expression behavior of the receptor and downstream molecules in climacteric and non climacteric crops is also elaborated upon. Possible strategies and recent advances in altering the ethylene sensitivity of plants using ethylene receptor genes in an attempt to modulate the regulation and sensitivity to ethylene have also been discussed. Not only will these transgenic plants be a boon to post-harvest physiology and crop improvement but, it will also help us in discovering the mechanism of regulation of ethylene sensitivity.Plant signaling & behavior 07/2012; 7(7):827-46.