Des variations d'activités de la 5′-nucléotidase et de l’adénylate-cyclase sont-elles des composantes de la levée d'inhibition du bourgeon cotylédonaire du pois?

Abstract

Pierre et Marie C~rrie. Biitirnerlt N 2 , 4, plcrce Jllssieli. 75230 Pnris. Frclr1c.e Rcqu Ic 12 avril 1984 NOUGAREDE, A., P. LANDRE, J . REMBUR ct M. NIEBLA HERNANDEZ. 1985. Dcs variations d'activitds dc la 5'-nuclCotidasc ct dc I'adCnylatc-cyclasc sont-cllcs dcs composantcs dc la IcvCc d'inhibition du bourgcon cotylCtlonairc du pois? Can. J. Bot. 63: 309-323. Lcs activitCs de I'adtnylatc-cyclasc ct dc la 5'-nuclCotidasc sont IocalisCcs 5 I'Cchcllc ultrastructuralc; lcurs variations sont cxaminCcs dans les ccllulcs dc transfcrt du nocud cotylddonairc du plant dc pois intact ct dCcapitC; cllcs sont aussi Ctudidcs dans lc mCristkmc du bourgcon cotylCdonairc inhibC (Ctat Go) ct cn cours dc rkactivation, durant Ics transitions G I -S ct G2-M. La surfacc extcrnc du plasmalcrnmc cst Ic support dc I'activitt dc I'adCnylatc-cyclasc qui sc manifcstc, dc faqon idcntiquc, dans Ics ccllulcs sp&cialistcs ct mCristCrnatiqucs, qucllc quc soit la phasc du cyclc ccllulairc. LC fluorurc tlc sodium n'cst pas un activatcur dc I'cnzymc vdgCtalc. LC plasmalcmme et Ics plasmodcsmcs sont Ics licux prCfCrenticls dc I'activitC dc la 5'-nuclCotidasc dcs ccllulcs spCcialisCcs ou mCristCmatiqucs, sans changcmcnt d'intcnsitC dans Ics ccllulcs du bourgcon sclon la phasc du cyclc. L'utilisation d'inhibitcurs dcs phosphatascs alcalincs (L-1)-bromotCtramisoIc ct L-phknylalaninc) ou dc la 5'-nuclCotidasc (a-P-mCthylknc adknosinc 5'-diphosphatc) rtvklcnt la spCcificitC dc cettc activitC plasmalcmmiquc. La constance dcs activitCs dc I'adCnylatc-cyclasc ct dc la 5'-nuclCotidasc dans le bourgcon inhibC ct cn cours dc rCactivation suggkrc quc I'optirnisation du pool dcs prCcurscurs dcs polynucltotidcs, si cllc cst unc composantc dc la IcvCc d'inhibition, n'cst pas assurCc par unc variation dcs activitCs dcs cnzymcs conduisant dc I'ATP i I'adtnosinc.NOUGAREDE, A,, P. LANDRE, J. REMBUR, and M. NIEBLA HERNANDEZ. 1985. Dcs variations d'activitks dc la 5'-nuclCotidasc ct dc I'adCnylatc-cyclasc sont-cllcs dcs composantcs de la IcvCc d'inhibition du bourgcon cotyledonairc du pois'! Can. J. Bot. 63: 309-323. Adcnylatc cyclasc and 5'-nuclcotidasc activitics wcrc localized at thc ultrastructural levcl. Variations of thcsc activitics wcrc chcckcd in thc transfcr cclls of thc cotylcdonary node in thc intact or decapitated plant. Thcy wcrc also studied in thc shoot apex of both inhibited (Go state) and relcascd cotylcdonary buds, during thc transitions G I -S or G1-M. Thc adcnylatc cyclasc activity is mainly associated with thc cxtcrior sidc of thc plasma mcmbranc and it is identical in both spccializcd and rneristcmatic cclls, no rnattcr what thc phase of thc ccll cyclc is. Sodium fluoride did not appcar as an activator of thc plant cnzyrne adcnylatc cyclasc. The 5'-nuclcotidasc activity was prcdominant on thc outside of thc plasma mernbranc and in thc plasmodesrnata with no variation of intensity in thc mcristcmatic cclls of thc bud in relation to thc ccll cyclc phases. Usc of inhibitors of alkalinc phosphatasc (L-p-bromotctrarnisolc and L-phcnylalaninc) and 5'-...

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“…(For a recent review on histochemical methodology the reader is referred to Richards & Richards (1998).) By such methods, early indications of the presence of adenylyl cyclase activity were found in plasma membrane, in endoplasmic reticulum and nuclear membranes in Zea mays root tips (Al-azzawi & Hall, 1976), on internal membranes of cytoplasmatic vacuoles in Pisum sativum (Hilton & Nesius, 1978), on the external side of the host plasma membrane and membranes surrounding the endophyte in root nodules of Alnus glutinosa (Gardner et al, 1979), and on the external side of the plasma membrane of Pisum sativum (Nougare ' de et al, 1984). Physiological roles have been proposed for plant adenylyl cyclase : Rougier et al (1988) postulated that adenylyl cyclase activity is a determining factor in the compatibility of pollen tube formation in Populus spp., whereas Curvetto & Delmastro (1990) located an adenylyl cyclase activity in Vicia faba guard cells that was selectively stimulated by IAA, Ca# + , caffeine, GTP, forskolin and, to a smaller extent, ABA.…”

Biological effects of pectic fragments in plant cells

“…In plants, the role of cAMP is unclear. Nougarede et al (1985) have localized adenylate cyclase activity in pea cotyledonary node using cytoenzymologic methods during the G1-S or G 2M transitions. Kurosaki et al (1987a,b) have shown that cAMP or analogues induced the synthesis of phytoalexins in carrot cells and Bolwell et al (1991) activated PAL and phytoalexin synthesis in beans by using forskolin, an activator of adenylate cyclase in animal cells.…”

Cytoenzymological analysis of adenylyl cyclase activity and 3′:5′‐cAMP immunolocalization in chloroplasts of Nicotiana tabacum

“…(Tu, 1974) using ATP as a substrate and lead as capturing agent. Using adenylylimidodiphosphate as a more specific substrate and lead as capturing agent, AC activity in Zea mays root tips was localized at the plasma membrane, endoplasmic reticulum and nuclear membranes (Al‐Azzawi & Hall, 1976), at internal membranes of cytoplasmic vacuoles in Pisum sativum (Hilton & Nesius, 1978), at the external side of the host plasma membrane and membranes surrounding the endophyte in root nodules of Alnus glutinosa (Gardner et al ., 1979), and at the external side of the plasma membrane of Pisum sativum (Nougarède et al ., 1984). Using strontium as a capturing agent and adenylylimidodiphosphate as substrate, AC activity was associated to membrane structures and the cell wall on both pollen and stigma side during pollination (Rougier et al ., 1988).…”