title: Targeted expression of cystatin restores fertility in cysteine protease induced male sterile tobacco plants.
abstract: Fertility restoration in male sterile plants is an essential requirement for their utilization in hybrid seed production. In an earlier investigation, we have demonstrated that the targeted expression of a cysteine protease in tapetal cell layer resulted in complete male sterility in tobacco transgenic plants. In the present investigation, we have used a cystatin gene, which encodes for a cysteine protease inhibitor, from a wild peanut, Arachis diogoi and developed a plant gene based restoration system for cysteine protease induced male sterile transgenic tobacco plants. We confirmed the interaction between the cysteine protease and a cystatin of the wild peanut, A. diogoi through in silico modeling and yeast two-hybrid assay. Pollen from primary transgenic tobacco plants expressing cystatin gene under the tapetum specific promoter- TA29 restored fertility on cysteine protease induced male sterile tobacco plants developed earlier. This has confirmed the in vivo interaction of cysteine protease and cystatin in the tapetal cells, and the inactivation of cysteine protease and modulation of its negative effects on pollen fertility. Both the cysteine protease and cystatin genes are of plant origin in contrast to the analogous barnase-barstar system that deploys genes of prokaryotic origin. Because of the deployment of genes of plant origin, this system might not face biosafety problems in developing hybrids in food crops.
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India. Electronic address: shklpwn@gmail.com.
authors.forename: Pawan
authors.initials: P
authors.lastname: Shukla
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India.
authors.forename: Mranu
authors.initials: M
authors.lastname: Subhashini
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India.
authors.forename: Naveen Kumar
authors.initials: NK
authors.lastname: Singh
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India.
authors.forename: Israr
authors.initials: I
authors.lastname: Ahmed
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India.
authors.forename: Shalibhadra
authors.initials: S
authors.lastname: Trishla
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad 500046, India. Electronic address: pbkirti@uohyd.ac.in.
authors.forename: P B
authors.initials: PB
authors.lastname: Kirti
mesh_terms: D010367:Arachis / Q000201:enzymology; D020090:Chromosome Segregation; D003198:Computer Simulation; D003433:Crosses, Genetic; D015891:Cystatins / Q000378:metabolism*; D057056:Cysteine Proteases / Q000378:metabolism*; D005298:Fertility; D018390:Gene Targeting; D008958:Models, Molecular; D051479:Plant Infertility; D030821:Plants, Genetically Modified; D011058:Pollen / Q000033:anatomy & histology / Q000378:metabolism / Q000648:ultrastructure; D011485:Protein Binding; D014026:Nicotiana / Q000235:genetics*; D020798:Two-Hybrid System Techniques
chemical_list: D015891:Cystatins; D057056:Cysteine Proteases
keywords: Cysteine protease–cystatin combination; Genetic engineering; Male fertility restoration; Male sterility; Pollination control system