Grigor T. Zehirov

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The study evaluated the response of pea (Pisum sativum cv. Avola) to arbuscular mycorrhizal fungi (AM) species Glomus mosseae and Glomus intraradices and Rhizobium leguminosarum bv. viceae, strain D 293, regarding the growth, photosynthesis, nodulation and nitrogen fixation activity. Pea plants were grown in a glasshouse until the flowering stage (35 days),(More)
Legume plants host nitrogen-fixing endosymbiotic Rhizobium bacteria in root nodules. In Medicago truncatula, the bacteria undergo an irreversible (terminal) differentiation mediated by hitherto unidentified plant factors. We demonstrated that these factors are nodule-specific cysteine-rich (NCR) peptides that are targeted to the bacteria and enter the(More)
The Tnt1 retrotransposon of tobacco (Nicotiana tabacum) has proven to be a very efficient mutagen for the model legume Medicago truncatula ecotype 108 and cultivar Jemalong 2HA and for economically important plants, such as soybean and potato. In this study, the activity of Tnt1 in the model legume Lotus japonicus L. was tested. First, a new regeneration(More)
Over the past decade, Medicago truncatula has been adopted as a model legume species for a range of “omic” studies. The availability of different transformation techniques has greatly advanced functional genomic studies in this species. In the present work, an efficient procedure for Agrobacterium-mediated transformation of M. truncatula cv. “Jemalong 2HA”(More)
Rhizobia establish symbiosis with legumes. Bacteroids in indeterminate nodules of Inverted Repeat Lacking Clade (IRLC) legumes undergo terminal differentiation caused by Nodule-specific Cysteine-Rich peptides (NCRs). Microscopic observations of bacteroids and the detection of NCRs in indeterminate nodules of the non-IRLC legume Leucaena glauca were(More)
In order to evaluate the role of aminopeptidases (APs) in drought response and their potential as protein markers to distinguish between stress tolerant and sensitive varieties, various AP activities were studied in roots and leaves of winter wheat seedlings, subjected to severe but recoverable soil drought stress. Two varieties with contrasting drought(More)
The symbiotic cells of legume nodules house large numbers of nitrogen-fixing, differentiated rhizobia, called bacteroids. In the legume Medicago truncatula, the symbiotic cells provoke terminal differentiation of bacteroids, which have altered membranes and are strongly enlarged due to genome endoreduplication and have lost the capacity for division.(More)
Exposure to transient 10-days boron (B) deficiency stress created during different periods of growth cycle of nodulated soybean plants grown in a liquid culture was found to inhibit the nodule number and to increase the nodule dry weight. Nodule fresh weight was decreased in the stressed plants especially in the older ones. The loss of tissue water in the(More)
In eukaryotes, histone acetyltransferases regulate the acetylation of histones and transcription factors, affecting chromatin structural organization, transcriptional regulation, and gene activation. To assess the role of HAC1, a gene encoding for a histone acetyltransferase in Medicago truncatula, stable transgenic lines with modified HAC1 expression in(More)
The influence of boron starvation on the root exudates content in soybean seedlings (Glycine max. L. Merr.) and the effect of exudates pretreatment on the pre-infection processes in symbiotic system Br. japonicum strain 636 and soybean were investigated. Root cell membrane stability of boron starved soybean plants (-B) decreased compared to the control. The(More)
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