caa a22 4500 397521456 CHVBK 20180308164634.0 cr unu---uuuuu 161202e199501 xx s 000 0 eng 10.1093/jxb/46.1.1-a doi (NATIONALLICENCE)oxford-10.1093/jxb/46.1.1-a A simple model based on known plant defence reactions is sufficient to explain most aspects of nodulation [Elektronische Daten] [Robert B. Mellor, David B. Collinge] We present the following hypothesis; that lipo-oligochitin Nod-factors can act in an elicitor-like fashion inducing, amongst other effects, a plant chitolytic enzyme, capable of hydrolysing the oligochitin chain of the Nod-factor. Decorative groups on the oligochitin chain, e.g. sulphate, may confer partial resistance to hydrolysis upon particular Nod-factors. After entry into the plant, Nod-factor synthesis must be down-regulated in order to avoid further, unwanted, eli-citation and the consequent abortion of the symbiosis. The plant-derived compounds inhibiting the synthesis of bacterial Nod-factors are limiting in root tissue, leading to residual elicitation and the abortion of infection thread formation. Nod-gene anti-induction is, furthermore, inactivated by both light and nitrate, thus contributing to the inhibition of nodulation under these conditions. In nitrogen-fixing nodules, the bacteroids are exposed to both nod-gene inducing and repressing compounds. The slow accumulation of Nod-factors within the peribacteroid space eventually results in the elicitation of phytoalexin synthesis and nodule senescence. © Oxford University Press Hypothesis Paper nationallicence Chitinase nationallicence elicitors nationallicence Leguminosae nationallicence Nod-factors nationallicence Rhizobium nationallicence symbiosis nationallicence Mellor Robert B. Department of Plant Biology, Royal Veterinary and Agricultural University Thorvaldsensvej 40, DK-1871Frederiksberg C, Denmark aut Collinge David B. Department of Plant Biology, Royal Veterinary and Agricultural University Thorvaldsensvej 40, DK-1871Frederiksberg C, Denmark aut Journal of Experimental Botany Oxford University Press 46/1(1995-01), 1-18 0022-0957 46:1<1 1995 46 exbotj https://doi.org/10.1093/jxb/46.1.1-a text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/jxb/46.1.1-a text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mellor Robert B. Department of Plant Biology, Royal Veterinary and Agricultural University Thorvaldsensvej 40, DK-1871Frederiksberg C, Denmark aut NATIONALLICENCE 700 1- Collinge David B. Department of Plant Biology, Royal Veterinary and Agricultural University Thorvaldsensvej 40, DK-1871Frederiksberg C, Denmark aut NATIONALLICENCE 773 0- Journal of Experimental Botany Oxford University Press 46/1(1995-01), 1-18 0022-0957 46:1<1 1995 46 exbotj Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford