Different Temporal and Spatial Gene Expression Patterns Occur during Anther Development.

Abstract

We studied the temporal and spatial regulation of three mRNA sequence sets that are present exclusively, or at elevated levels, in the tobacco anther. One mRNA set accumulates in the tapetum and decays as the tapetum degenerates later in anther development. The second mRNA set accumulates after the tapetal-specific mRNAs, is localized within the stomium and connective, and also decays as these cell types degenerate during anther maturation. The third mRNA sequence set persists throughout anther development and is localized within most anther tissues. A tapetal-specific gene, designated as TA29, was isolated from a tobacco genome library. Runoff transcription studies and experiments with chimeric p-glucuronidase and diphtheria toxin A-chain genes showed that the TA29 gene is regulated primarily at the transcriptional leve1 and that a 122-base pair 5' region can program the tapetal-specific expression pattern. Destruction of the tapetum by the cytotoxic gene had no effect on the differentiation and/or function of surrounding sporophytic tissues but led to the production of male-sterile plants. Together, our studies show that several independent gene expression programs occur during anther development and that these programs correlate with the differentiated state of specific anther cell types.

Early flowering and genetic containment studies in transgenic poplar

“…Specific floral regulatory promoters to direct expression of genes in reproductive structures have been found in crop plants, e.g., TA29 promoter from Nicotiana tabacum (Koltunow et al 1990, Mariani et al 1990) and forest tree species, e.g., PrMA-LE1 from Pinus radiata (Höfig et al 2003) and PTD from poplar (Skinner et al 2003).…”

Identification of the NtFZY gene family in Tobacco (Nicotiana tabacum) involved in the tryptophan-dependent auxin biosynthesis pathway

“…The content of IAA was determined in flowers at different stages of development according to the clas sification of Goldberg [10] modified by Koltunow [11] after fixing in liquid nitrogen and subsequent lyo philization for 18 h in an Inei 6 device (Russia). Indole 3 acetic acid was extracted from the lyo philized flower tissues as described previously [12].…”

An <i>in silico</i> Analysis of Upstream Regulatory Modules (URMs) of Tapetum Specific Genes to Identify Regulatory <i>cis</i>-Elements and Transcription Factors

“…Tapetum varies from unilayer to multilayer in different plant species and can be uninucleate or multinucleate. Although tapetum cells form a single or at-most a few cell layers in the anther tissue, several studies have been carried out to understand how these cell layers develop and the functions played by them in pollen cell development [1] [2] [3] [4]. These studies have led to the identification of several genes expressed in tapetum specific manner.…”

“…These studies have led to the identification of several genes expressed in tapetum specific manner. Such genes have mainly been identified by analyzing comparative cDNA libraries, subtractive hybridization, microarray analysis, in-situ hybridization and in recent years by Laser Dissection Microscopy followed by RNA sequencing [1] [5]- [16].…”

“…TA29 from Nicotiana tabacum [1] and A9 from Arabidopsis thaliana [6] are examples of tapetum specific genes that were identified in early years. The promoters of these genes known as TA29 and A9 promoters have been used extensively in the expression of transgenes like barnase and barstar from Bacillus amyloliquifaciens to develop pollination control systems for hybrid seed production [5] [21].…”