The Promoter of the Vicia faba L. Leghemoglobin Gene VfLb29 Is Specifically Activated in the Infected Cells of Root Nodules and in the Arbuscule-Containing Cells of Mycorrhizal Roots from Different Legume and Nonlegume Plants

Abstract

The VfLb29 leghemoglobin gene promoter was polymerase chain reaction-amplified from a Vicia faba genomic library and was fused to the gusAint coding region. Expression of the chimeric gene was analyzed in transgenic hairy roots of the legumes V. faba, V. hirsuta, and Medicago truncatula as well as in transgenic Nicotiana tabacum plants. The VfLb29 promoter was found to be specifically active not only in the infected cells of the nitrogen-fixing zone of root nodules but also in arbuscule-containing cells of transgenic V. faba and M. truncatula roots colonized by the endomycorrhizal fungus Glomus intraradices. In addition to these two legumes, specific expression in arbuscule-containing cells was also observed in the nonlegume N. tabacum. All studies were done in comparison to the V. faba leghemoglobin gene promoter VfLb3 that as VfLb29 was expressed in the infected cells of root nodules but showed no activity in endomycorrhiza. An activation of the VfLb29 promoter due to hypoxia in metabolically active tissues was excluded. The conserved activation in arbuscule-containing cells of legumes and the nonlegume N. tabacum suggests a conserved trigger for this promoter in legume and nonlegume endomycorrhiza symbioses.

A cytochrome P450 regulates a domestication trait in cultivated tomato

“…The tandem repeat was located 440 bp to 559 bp upstream from the SlKLUH transcription start site. Moreover, M9 mutation is located within a putative cis element, related to the organ-specific element (OSE) found in nodulin and leghemoglobin genes in soybean and Vicia faba (33)(34)(35). In the future, it will be interesting to assess the role of this putative cis-element in gene expression and to explore whether the tandem repeat has any bearing on the modulation of SlKLUH expression.…”

Arbuscular mycorrhizal networks: process and functions. A review

“…AGL proteins encoded by two AGL genes from G. intraradices (GiAGLs) represent a new class of AGPs not found in non-AM plants (Schultz and Harrison, 2008). Interestingly, several genes have been identified that are induced both in mycorrhized cortical cells and during rhizobial root colonization in legume species; for example, the early nodulin genes ENOD2, ENOD40 (van Rhijn et al, 1997) and ENOD11 (Chabaud et al, 2002), the Vicia faba leghemoglobin gene VFLb29 (Vieweg et al, 2004), and the gene calcium-binding protein 1 (Cbp1), which encodes a protein sharing similarities with calcium-binding proteins (Kistner et al, 2005). This supports the model outlined for the common symbiotic pathway in AM and rhizobium-induced nodule development using signal transduction based on conserved mechanisms (Paszkowski, 2006;Bucher, 2007).…”

Testing for mycorrhizal fungi-plant-ant indirect effects

“…Before planting, the emerging radicles of M' seedlings were dipped in a mycorrhizal inoculant (Bio/Organics, Inc., LaPine, OR, USA) that was composed of crushed rock and the spores of several AMF species (Glomus aggregatum, G. clarum, G. deserticola, G. intraradices, G. monosporus, G. mosseae, Gigaspora margarita, and Paraglomus brasilianum), some of which (G. mosseae, G. intraradices, and G. clarum) are known to participate in mycorrhizal symbioses with V. faba (Kucey and Paul 1982;Vieweg et al 2004;Rabie and Almadini 2005). During planting, M' plants were placed directly atop 5 ml of the inoculant.…”