A novel hybrid seed system for plants

Abstract

SummaryA two-component hybrid seed system has been developed that is broadly applicable and provides for effective generation and maintenance of the male-sterile parent, hybrid seed production and full restoration of fertility in the hybrid seed. The technology is based on the functional interaction of two loci that are inserted in the same position on two homologous chromosomes, and thus are 'linked in repulsion', and that jointly code for male sterility and herbicide resistance, both traits being expressed in heterozygous plants only. The localization to the same locus on a chromosome is achieved by the genetic transformation of plants with a construct containing both genetic elements (loci), and subsequent derivatization from the primary pro-locus of the two precursor lines using site-specific deletions. The functional interaction of the two loci is achieved through intein-based trans -splicing of two pairs of complementary protein fragments that provide for male sterility and herbicide resistance. Unlike the hybrid seed systems that are currently in use, the technology relies on the genetic modification of just one parent, and is therefore much simpler to develop and use. Arabidopsis has been used for the proof of principle presented here, but the essential elements of the technology are generic and have been shown to work in many crop species.

Recent progress in intein research: from mechanism to directed evolution and applications

“…Another classical example for an application that exploits the posttranslational character of the protein trans-splicing reaction is the reconstitution of foreign gene products incorporated in transgenic plants. After fragmentation of the encoding gene into two pieces, each fused with a split intein gene, the resulting two DNA constructs are separated, e.g., placed into the nuclear and the chloroplast genome, to dramatically reduce the risk of spreading the entire transgene [117][118][119].…”

Transgenic Plants as Biofactories for the Production of Biopharmaceuticals: A Case Study of Human Placental Lactogen

“…Chloroplast transformation technology is a very attractive approach as chloroplast genome is maternally inherited in most crops, and gene spread via pollen occurs at low frequency (Svab & Maliga, 2007). The use of male-sterile plants (Gils et al, 2008) or "terminator" technology (also known as GURTs, "Genetic use restriction technologies), which is based on a repressible system to produce plants with non-viable seeds unless the plants are exposed to specific activators (Lee & Natesan, 2006), have also been used to contain transgenes. Other strategies include organ-or tissue-specific expression of transgenes, ER-retention of proteins and inducible promoters (Obembe et al, 2010).…”

Intron hairpin and transitive RNAi mediated silencing of orfH522 transcripts restores male fertility in transgenic male sterile tobacco plants expressing orfH522

“…Several investigators have reported the development of transgenic male sterile plants using different approaches and strategies (Yamini et al 2007;Gils et al 2008;Yamamoto et al 2008;Nizampatnam et al 2009;Bihao et al 2010;Toppino et al 2010;Zhang et al 2010). However, only a few have reported the development of appropriate transgenic lines to restore fertility in the male sterile lines (Schmülling et al 1993;Zabaleta et al 1996;Bayer and Hess 2005;Li et al 2007;Gils et al 2008;Bihao et al 2010;Toppino et al 2010). Also, in cases where fertility restoration has been reported, the problem in achieving complete restoration has been highlighted (Schmülling et al 1993;Hird et al 2000;Bisht et al 2004;Busi et al 2006).…”