A note on evidence for involvement of pectolytic enzymes in the infection process of <i>Medicago sativa</i> by <i>Rhizobium meliloti</i>

Martianez‐Molina, E.; Olivares, José

doi:10.1111/j.1365-2672.1982.tb05076.x

Cited by 9 publications

(4 citation statements)

References 10 publications

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“…However, sensitive procedures to detect minute amounts of cell wall-degrading enzymes were not available. More recently, several studies have detected pectinolytic (17,22,23,29,30,36), cellulolytic (25,36), and hemicellulolytic (21,22) enzyme activities from pure cultures of rhizobia. In general, the activities of these rhizobial enzymes are very low and at the limit of sensitivity of conventional reducing sugar assays; this has hampered research progress in this area.…”

mentioning

confidence: 99%

Cell-associated pectinolytic and cellulolytic enzymes in Rhizobium leguminosarum biovar trifolii

Mateos

Jiménez‐Zurdo

Chen

et al. 1992

Appl Environ Microbiol

148

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The involvement of Rhizobium enzymes that degrade plant cell wall polymers has long been an unresolved question about the infection process in root nodule symbiosis. Here we report the production of enzymes from Rhizobium leguminosarum bv. trifolii that degrade carboxymethyl cellulose and polypectate model substrates with sensitive methods that reliably detect the enzyme activities: a double-layer plate assay, quantitation of reducing sugars with a bicinchoninate reagent, and activity gel electrophoresis-isoelectric focusing. Both enzyme activities were (i) produced commonly by diverse wild-type strains, (ii) cell bound with at least some of the activity associated with the cell envelope, and (iii) not changed appreciably by growth in the presence of the model substrates or a flavone that activates expression of nodulation (nod) genes on the resident symbiotic plasmid (pSym). Equivalent levels of carboxymethyl cellulase activity were found in wild-type strain ANU843 and its pSym-cured derivative, ANU845, consistent with previous results of Morales et al. (V. Morales, E. Martínez-Molina, and D. Hubbell, Plant Soil 80:407-415, 1984). However, polygalacturonase activity was lower in ANU845 and was not restored to wild-type levels in the recombinant derivative of pSym- ANU845 containing the common and host-specific nod genes within a 14-kb HindIII DNA fragment of pSym from ANU843 cloned on plasmid pRt032. Activity gel electrophoresis resolved three carboxymethyl cellulase isozymes of approximately 102, 56, and 33 kDa in cell extracts from ANU843. Isoelectric focusing activity gels revealed one ANU843 polygalacturonase isozyme with a pI of approximately 7.2. These studies show that R. leguminosarum bv. trifolii produces multiple enzymes that cleave glycosidic bonds in plant cell walls and that are cell bound.

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mentioning

confidence: 99%

Cell-associated pectinolytic and cellulolytic enzymes in Rhizobium leguminosarum biovar trifolii

Mateos

Jiménez‐Zurdo

Chen

et al. 1992

Appl Environ Microbiol

148

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“…Several studies have detected pectinolytic (Martinz‐Molina and Olivares 1982), cellulolytic (Saleh‐Rastin et al. 1991) and hemicellulolytic (Lopez and Singer 1987) enzyme activities from pure cultures of rhizobia.…”

Section: Introductionmentioning

confidence: 99%

“…Several studies have detected pectinolytic (Martinz-Molina and Olivares 1982), cellulolytic (Saleh-Rastin et al 1991) and hemicellulolytic (Lopez and Singer 1987) enzyme activities from pure cultures of rhizobia. Especially Mateos et al (1992) developed assays with improved sensitivity and reliability to detect and measure celluloytic and pectinolytic activities; these were used to demonstrate the production of both enzyme activities by different wild type strains of the clover root-nodule symbiont, Rhizobium leguminosarum bv.…”

Section: Introductionmentioning

confidence: 99%

Cloning and characterization of cel8A gene from Rhizobium leguminosarum bv. trifolii 1536*

Lim

Hong

et al. 2004

Lett Appl Microbiol

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Aims: To isolate the cellulase gene from Rhizobium leguminosarum bv. trifolii 1536. Methods and Results: By the shot-gun method a clone (cel8A) harbouring 3AE1 kb genomic DNA fragment from R. leguminosarum bv. trifolii 1536 was obtained. The cel8A gene coded 348 amino acids and it belongs to the glycosyl hydrolase family 8. The molecular mass of Cel8A protein induced from Escherichia coli DH5a, appeared to be 35 kDa. The optimum pH and optimum temperature was 7AE0, and about 30°C for its enzymatic activity respectively. Conclusions: R. leguminosarum bv. trifolii 1536 had cel8A gene having an open reading frame of 1047 bp coded for the activity of hydrolyzation of carboxymethyl cellulose. Significance and Impact of the Study: The production of celluloytic enzyme by R. leguminosarum bv. trifolii was confirmed, which would play specific roles in rhizobia. Future study should focus on its role in the infection and nodulation phenomena.

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“…Στο σημείο αυτό το κυτταρικό τοίχωμα υδρολύεται τοπικά (Callaham andTorrey, 1981, Turgeon andBauer, 1982). Δεν έχει γίνει σαφές εάν η λύση των κυπαρικών τοιχωμάτων Οφείλεται σε υδρολυτικά ένζυμα των βακτηρίων ή εάν τα βακτήρια επάγουν την ενεργοποίηση ενδογενών φυτικών υδρολυτικών μηχανισμών (Martinez-Molina andOlivares, 1982, Kijne, 1992). Ταυτόχρονα με την υδρόλυση, η ανάπτυξη των κυτταρικών τοιχωμάτων των ριζικών τριχιδίων επανακατευθυνεται (Tate et al, 1994) έτσι ώστε να σχηματίζεται το μολυσματικό νημάτιο.…”

Section: α23 έναρξη της μολύνσεως και σχηματισμός του μολυσματικού νηματίουunclassified

Μελέτη Της Έκφρασης Των Γονιδίων Των Πρώιμων Και Όψιμων Νοντουλινών Στα Φυμάτια Σόγιας

Καβρουλάκης¹

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Καταρχήν θα ήθελα να ευχαριστήσω τον Αν. Keß κ,Κατινάκη Π. ο οττοίος υπήρξε ο επιβλέπων καθηγητής κατά την διάρκεια εκπόνησης της παρούσας διατριβής. Ευχαριστώ επίσης και τα άλλα δύο μέλη της συμβουλευτικής επιτροπής, τον Keß κ.Δροσόπουλο Ι. και m Αν. Keß. κ.Χατζόττουλο Π. Θα ήταν παράληψη να μην αναφερθώ και στα ονόματα των DrJ.J. Drevon, (INRA, France) και Dr Ν. Brewin, (John Innés Centra, Great Britain) οι οποίοι όχι μόνο με δέχτηκαν στα εργαστήρια τους αλλά ξόδεψαν και πολύ από το χρόνο τους σε συζητήσεις μαζί μου πάνω στο θέμα και τα αποτελέσματα της παρούσας διατριβής. Θα πρέπει επίσης να εκφράσω τις ειλικρινείς ευχαριστίες μου στους συναδέλφους με τους οποίους κατά καιρούς συνεργάστηκα για την κάθε είδους, από μέρους τους, βοήθεια. Επιβάλλεται τέλος να ευχαριστήσω και το Ίδρυμα Κρατικών Υποτροφιών (Ι.Κ.Υ.) για την χορήγηση της υποτροφίας με την οποία διευκολύνθηκε η πραγματοποίηση της παρούσας μελέτης. "Η έγκρισις της παρούσης διδακτορικής διατριβής υπό του Γεωπονικού Πανβπιστημίου Αθηνών δβν υποδηλβΐ αποδοχήν των γνώμεων του συγγραφέως" (Νόμος 5343/1932, άρθρο 202) Α ΕΙΣΑΓΩΓΗ A.

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A note on evidence for involvement of pectolytic enzymes in the infection process of Medicago sativa by Rhizobium meliloti

Abstract: Evidence has been obtained of the implication of pectolytic enzymes in the infection of alfalfa roots by Rhizobium meliloti.

Cited by 9 publications

References 10 publications

Cell-associated pectinolytic and cellulolytic enzymes in Rhizobium leguminosarum biovar trifolii

Cell-associated pectinolytic and cellulolytic enzymes in Rhizobium leguminosarum biovar trifolii

Cloning and characterization of cel8A gene from Rhizobium leguminosarum bv. trifolii 1536*

Μελέτη Της Έκφρασης Των Γονιδίων Των Πρώιμων Και Όψιμων Νοντουλινών Στα Φυμάτια Σόγιας

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