Interspecies compatibility of the anther specific cell wall invertase promoters from Arabidopsis and tobacco for generating male sterile plants

Abstract

Histochemical GUS-staining and fluorometric analyses revealed strong tissue specific activities of the cell wall invertase promoters Nin88 from Nicotiana tabacum and AtcwINV2 from Arabidopsis thaliana that are restricted tightly to anthers and pollen, respectively. Both in A. thaliana and N. tabacum repression of invertase activity by anther specific RNA-interference turned out to be an efficient method to circumvent carbohydrate supply of the symplastically isolated pollen with subsequent strong decrease of pollen germination ability and seed setting. In the case of tobacco, comparable results were also obtained by expressing a proteinaceous invertase inhibitor, whereas this approach was less efficient in Arabidopis. The present study revealed that anther specific interference with invertase-activity in order to generate male sterile plants can be applied to members of the two different plant families Solanaceae (N. tabacum) and Brassicaceae (A. thalaina) and the strategy seems to be a general tool for practical application in hybrid breeding or as biological safety precautions. To elucidate the compatibility of the isolated promoters beyond plant families, we transferred the regulatory sequences into the respectively heterologous systems, i.e. the Nin88 promoter into Arabidopsis and the AtcwINV2 promoter into tobacco. The specificities of both promoters are maintained in the heterologous backgrounds, but their activities are strongly reduced as GUS-stainings of flowers and pollen revealed and fluorometrical quantification confirmed.

Expression of RNA-Interference/Antisense Transgenes by the Cognate Promoters of Target Genes Is a Better Gene-Silencing Strategy to Study Gene Functions in Rice

“…Regulated promoters such as organ/tissue- or developmental stage-specific promoters [14], [15] and physically/chemically-inducible promoters [16], [17], [18], [19], [20] have been used in the past to better control the expression of an RNAi/antisense transgene avoiding the adverse effects of constitutive promoters. However, these promoters have their own limitations as an RNAi/antisense-transgene driven by a regulated promoter will only be expressed in certain tissues/organs, at specific developmental stages, or in response to a unique chemical/physical signal but has no effect on the target gene in other relevant tissues/organs at certain important developmental stages [21].…”

Loss of Cytosolic Phosphoglucomutase Compromises Gametophyte Development in Arabidopsis

“…During these steps, it is also likely that invertase rather than Susy is responsible for Suc metabolism. Repression of cell wall invertase isoforms has been shown to disrupt pollen development (Goetz et al, 2001;Hirsche et al, 2009). Thus, Suc would be cleaved outside the cell and the resulting monosaccharides imported, again raising the question as to how Glc-1-P is synthesized.…”

Understanding the Role of Defective Invertases in Plants: Tobacco Nin88 Fails to Degrade Sucrose

“…cwINVs often play a crucial role in phloem unloading in sink tissues by creating a Suc gradient, enhancing sink strength-mediated long-distance transport of Suc (Sturm, 1999). Their function is most prominent in sinks with no plasmodesmatal connections between cells, such as developing seeds and pollen (Proels et al, 2006;Hirsche et al, 2009;Kang et al, 2009). The expression and activity of cwINVs are regulated by a number of stimuli that are known to affect carbohydrate requirements, such as phytohormones (Balibrea-Lara et al, 2004;Hayes et al, 2010) and pathogen infection (Benhamou et al, 1991;Siemens et al, 2011).…”