The Regulation of 1-Aminocyclopropane-1-Carboxylic Acid Synthase Gene Expression during the Transition from System-1 to System-2 Ethylene Synthesis in Tomato

Cornelius S. Barry, M. Immaculada Llop-Tous, Donald Grierson
2000 Plant Physiology  
1-Aminocyclopropane-1-carboxylic acid synthase (ACS) is one of the key regulatory enzymes involved in the synthesis of the hormone ethylene and is encoded by a multigene family containing at least eight members in tomato (Lycopersicon esculentum). Increased ethylene production accompanies ripening in tomato, and this coincides with a change in the regulation of ethylene synthesis from auto-inhibitory to autostimulatory. The signaling pathways that operate to bring about this transition from
more » ... alled system-1 to system-2 ethylene production are unknown, and we have begun to address these by investigating the regulation of ACS expression during ripening. Transcripts corresponding to four ACS genes, LEACS1A, LEACS2, LEACS4, and LEACS6, were detected in tomato fruit, and expression analysis using the ripening inhibitor (rin) mutant in combination with ethylene treatments and the Never-ripe (Nr) mutant has demonstrated that each is regulated in a unique way. A proposed model suggests that system-1 ethylene is regulated by the expression of LEACS1A and LEACS6. In fruit a transition period occurs in which the RIN gene plays a pivotal role leading to increased expression of LEACS1A and induction of LEACS4. System-2 ethylene synthesis is subsequently initiated and maintained by ethylene-dependent induction of LEACS2. LITERATURE CITED Abeles FB, Morgan PW, Saltveit ME (1992) Ethylene in Plant Biology. Academic Press, San Diego Barry CS, Blume B, Bouzayen M, Cooper W, Hamilton AJ, Grierson D (1996) Differential expression of the 1aminocyclopropane-1-carboxylate oxidase gene family of tomato. Plant J 9: 525-535 Blume B, Barry CS, Hamilton AJ, Bouzayen M, Grierson D (1997) Identification of transposon-like elements in non-coding regions of tomato ACC oxidase genes. Mol Gen Genet 254: 297-303 Blume B, Grierson D (1997) Expression of ACC oxidase promoter-GUS fusions in tomato and Nicotiana plumbaginifolia regulated by developmental and environmental stimuli. Plant J 12: 731-746 Dong JG, Fernández-Maculet JC, Yang SF (1992) Purification and characterization of 1-aminocyclopropane-1carboxylate oxidase from apple fruit. Proc Natl Acad Sci USA 89: 9789-9793 Griffiths A, Barry C, Alpuche-Solis AG, Grierson D (1999) Ethylene and developmental signals regulate expression of lipoxygenase genes during tomato fruit ripening. J Exp Bot 50: 793-798 Guis M, Bouquin T, Zegzouti H, Ayub R, Ben Amor M, Lasserre E, Botondi R, Raynal J, Latché A, Bouzayen M, Balagué C, Pech, JC (1997) Differential expression of ACC oxidase genes in melon and physiological characterization of fruit expressing an antisense ACC oxidase gene. In A Kanellis, C Chang, H Kender, D Grierson, eds, Biology and Biotechnology of the Plant Hormone Ethylene. Kluwer Academic Publishers, Dordrecht, The Netherlands, pp 327-338 Hamilton AJ, Lycett GW, Grierson D (1990) Antisense gene that inhibits synthesis of the hormone ethylene in transgenic plants. Nature 346: 284-287 Herner RC, Sink KC (1973) Ethylene production and respiratory behavior of the rin tomato mutant. Plant Physiol 52: 38-42 Holdsworth MJ, Schuch W, Grierson D (1988) Organisation and expression of a wound/ripening-related small multigene family from tomato.
doi:10.1104/pp.123.3.979 pmid:10889246 pmcid:PMC59060 fatcat:7jd75heclfhefau5y5th6yavva