The Role of Proline in Osmoregulation in Phytophthora nicotianae

Ambikapathy, Jesmini; Marshall, Jerry S.; Hocart, Charles H.; Hardham, Adrienne R.

doi:10.1006/fgbi.2001.1327

Cited by 35 publications

(21 citation statements)

References 41 publications

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“…1,2 Free proline has been shown to accumulate in response to osmotic stress in a wide variety of organisms, implying a role in stress tolerance and osmoregulation. 3 Whereas proline accumulation is a primitive response to osmotic stress, the source of this accumulation seems to be different. In eubacteria, proline accumulation occurs via enhanced uptake from activated transcription of the operons encoding proline permease (proP and proU).…”

Section: Introductionmentioning

confidence: 99%

Crystal Structures of Δ1-Pyrroline-5-carboxylate Reductase from Human Pathogens Neisseria meningitides and Streptococcus pyogenes

Nocek¹,

Chang²,

Li³

et al. 2005

Journal of Molecular Biology

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L-Proline is an amino acid that plays an important role in proteins uniquely contributing to protein folding, structure, and stability, and this amino acid serves as a sequence-recognition motif. Proline biosynthesis can occur via two pathways, one from glutamate and the other from arginine. In both pathways, the last step of biosynthesis, the conversion of Δ 1 -pyrroline-5-carboxylate (P5C) to Lproline, is catalyzed by Δ 1 -pyrroline-5-carboxylate reductase (P5CR) using NAD(P)H as a cofactor. We have determined the first crystal structure of P5CR from two human pathogens, Neisseria meningitides and Streptococcus pyogenes, at 2.0Å and 2.15Å resolution, respectively. The catalytic unit of P5CR is a dimer composed of two domains, but the biological unit seems to be speciesspecific. The N-terminal domain of P5CR is an α/β/α sandwich, a Rossmann fold. The C-terminal dimerization domain is rich in α-helices and shows domain swapping. Comparison of the native structure of P5CR to structures complexed with L-proline and NADP + in two quite different primary sequence backgrounds provides unique information about key functional features: the active site and the catalytic mechanism. The inhibitory L-proline has been observed in the crystal structure.

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Section: Introductionmentioning

confidence: 99%

Crystal Structures of Δ1-Pyrroline-5-carboxylate Reductase from Human Pathogens Neisseria meningitides and Streptococcus pyogenes

Nocek¹,

Chang²,

Li³

et al. 2005

Journal of Molecular Biology

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“…Proline accumulation occurs in plants under various abiotic stresses (Ashraf and Foolad 2007). Proline play a key role in osmoregulation and bioenergatics of cell (Ambikapathy et al 2002;Pandhare et al 2009). The combined treatment of all 3-PGPR and 2-PGR (T 6 ) had significantly reduced the proline content, which may be attributed possibly to PGR and PGPR induced regulation of osmotic balance and maintenance of the bioenergetics of the cell.…”

Section: Discussionmentioning

confidence: 99%

Effects of exogenously applied plant growth regulators in combination with PGPR on the physiology and root growth of chickpea (Cicer arietinum) and their role in drought tolerance

Khan

Bano

Zandi

2018

Journal of Plant Interactions

148

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Both the plant growth promoting rhizobacteria (PGPR) and plant growth regulators (PGR) exert beneficial effects on plant growth even under stress, but combined effect of both of them has not been evaluated yet. Present investigation was aimed to determine the responses of 2 chickpea varieties (differing in drought tolerance) to 3 PGPR viz. Bacillus subtilis, Bacillus thuringiensis and Bacillus megaterium and PGR (SA and Putrescine) on physiology of chickpea grown in sandy soil. The PGR, Salicylic acid (SA) and Putrescine (Put) were sprayed on the seedling 20 days after germination. Results revealed, synergistic effects of PGPR and PGR on chlorophyll, protein and sugar contents. Addition of PGR to PGPR inoculated plants assisted the plant in osmoregulation and amelioration of oxidative stresses and in induction of new proteins. Combined application of PGR and PGPR decreased lipid peroxidation more effectively but increased the leaf area. It is inferred that PGPR and PGR work synergistically to promote growth of plants under moisture and nutrient deficit condition of sandy soil. Since, SA induces Systemic Acquired Resistance (SAR) in plants hence the addition of SA along with PGPR may render the plant more productive and better tolerant to diseases/pathogen attack. ARTICLE HISTORY

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“…Transcripts accumulated quickly after exposing sporangia to cool water, which initiates the cleavage of sporangial cytoplasm into individual zoospores. The kinase appears to be induced much earlier than the only other gene known to be activated in the zoospore pathway, which encodes a proline biosynthesis enzyme from P. parasitica (1). Levels of mRNA from the P. parasitica gene peak 4 h after zoospores are liberated, compared to those of the P. infestans kinase, which climax prior to release.…”

Section: Discussionmentioning

confidence: 92%

Novel Protein Kinase Induced during Sporangial Cleavage in the Oomycete Phytophthora infestans

Judelson

Roberts

2002

Eukaryot Cell

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A study of the effect of inhibitors on zoospore development in Phytophthora infestans demonstrated the involvement of protein kinases and calcium and led to the discovery of a gene induced during zoosporogenesis that encoded a protein resembling Ca ؉2 -and calmodulin-regulated serine/threonine protein kinases. The calcium channel blocker verapamil and the calmodulin antagonist trifluoroperazine inhibited zoosporogenesis and encystment. The protein kinase inhibitors K-252a and KN-93 inhibited zoospore release, encystment, and cyst germination, and K-252a reduced zoospore viability. In contrast, the inhibitors had minor or no effects on sporangia directly germinating in media. Spurred by these findings, a survey of putative protein kinase genes was performed to identify any that were up-regulated during zoosporogenesis. A kinase-encoding gene was identified for which mRNA accumulation was first detected soon after chilling sporangia in water, conditions that induce sporangial cytoplasm to cleave and release zoospores. The transcript persisted in motile zoospores and in germinated cysts but was not detected in other tissues, including hyphae, hyphae placed in water, or directly germinating sporangia. The structure of the predicted protein was novel, as its C-terminal region, which binds calmodulin in related proteins, was unusually short. Concentrations of actinomycin D previously used in experiments that suggested that de novo transcription was not needed for zoosporogenesis or encystment only partially inhibited transcription of the kinase gene, probably due to poor uptake into sporangia.Dispersal by means of spores is a common feature of the life cycle of many lower eukaryotes. This includes the oomycetes, which encompass many important plant pathogens, including Phytophthora, Pythium, and the downy mildews. Oomycetes lack taxonomic affinity with the so-called true fungi (i.e., ascomycetes and basidiomycetes), instead being related to diatoms and brown algae (2, 15). The asexual sporangia of oomycetes either germinate directly through a germ tube or indirectly by releasing biflagellate zoospores. Many species germinate through either pathway, while others produce only zoospores and some germinate only directly (12,22,26). For species displaying both modes of germination, zoospores are considered most important for dispersal and host infection.One species exhibiting this duality in germination behavior is Phytophthora infestans, which causes late blight of potato and tomato. Sporangia form on sporangiophores that emerge from infected plant tissue or from hyphae on artificial media. As with other oomycetes, the sporangia of P. infestans are multinucleate, nondesiccated, and metabolically active. Germination becomes possible once sporangia detached from sporangiophores encounter liquid. Indirect germination predominates in the absence of nutrients and at cool temperatures, typically below 12°C (30). In contrast, direct germination is favored by higher temperatures and nutrients. Indirect germination takes about 1 h...

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The Role of Proline in Osmoregulation in Phytophthora nicotianae

Cited by 35 publications

References 41 publications

Crystal Structures of Δ1-Pyrroline-5-carboxylate Reductase from Human Pathogens Neisseria meningitides and Streptococcus pyogenes

Crystal Structures of Δ1-Pyrroline-5-carboxylate Reductase from Human Pathogens Neisseria meningitides and Streptococcus pyogenes

Effects of exogenously applied plant growth regulators in combination with PGPR on the physiology and root growth of chickpea (Cicer arietinum) and their role in drought tolerance

Novel Protein Kinase Induced during Sporangial Cleavage in the Oomycete Phytophthora infestans

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