caa a22 4500 467894655 CHVBK 20180406152759.0 cr unu---uuuuu 170328e20060501xx s 000 0 eng 10.1007/s11103-006-0009-8 doi (NATIONALLICENCE)springer-10.1007/s11103-006-0009-8 Regulatory Role of Cystathionine-γ-Synthase and de novo Synthesis of Methionine in Ethylene Production during tomato Fruit Ripening [Elektronische Daten] [Yael Katz, Gad Galili, Rachel Amir] The essential amino acid methionine is a substrate for the synthesis of S-adenosyl-methionine (SAM), that donates its methyl group to numerous methylation reactions, and from which polyamines and ethylene are generated. To study the regulatory role of methionine synthesis in tomato fruit ripening, which requires a sharp increase in ethylene production, we cloned a cDNA encoding cystathionine γ-synthase (CGS) from tomato and analysed its mRNA and protein levels during tomato fruit ripening. CGS mRNA and protein levels peaked at the "turning” stage and declined as the fruit ripened. Notably, the tomato CGS mRNA level in both leaves and fruit was negatively affected by methionine feeding, a regulation that Arabidopsis, but not potato CGS mRNA is subject to. A positive correlation was found between elevated ethylene production and increased CGS mRNA levels during the ethylene burst of the climacteric ripening of tomato fruit. In addition, wounding of pericarp from tomato fruit at the mature green stage stimulated both ethylene production and CGS mRNA level. Application of exogenous methionine to pericarp of mature green fruit increased ethylene evolution, suggesting that soluble methionine may be a rate limiting metabolite for ethylene synthesis. Moreover, treatment of mature green tomato fruit with the ethylene-releasing reagent Ethephon caused an induction of CGS mRNA level, indicating that CGS gene expression is regulated by ethylene. Taken together, these results imply that in addition to recycling of the methionine moieties via the Yang pathway, operating during synthesis of ethylene, de novo synthesis of methionine may be required when high rates of ethylene production are induced. Springer, 2006 climacteric fruit nationallicence cystathionine-γ-synthase nationallicence ethylene nationallicence methionine metabolism nationallicence tomato nationallicence ACC : aminocyclopropane carboxylate nationallicence CGS : cystathionine-γ-synthase nationallicence Le : Lycopersicon esculentum nationallicence MTR : methylthioribose nationallicence SAM : S-adenosyl-methionine nationallicence SAHH : S-adenosine-homocysteine hydrolase nationallicence SMM : S-methylmethionine nationallicence Katz Yael Plant Science Laboratory, Migal Galilee Technological Center, Kiryat Shmona, Israel aut Galili Gad Department of Plant Sciences, The Weizmann Institute of Science, 76100, Rechovot, Israel aut Amir Rachel Plant Science Laboratory, Migal Galilee Technological Center, Kiryat Shmona, Israel aut Plant Molecular Biology Kluwer Academic Publishers 61/1-2(2006-05-01), 255-268 0167-4412 61:1-2<255 2006 61 11103 https://doi.org/10.1007/s11103-006-0009-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11103-006-0009-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Katz Yael Plant Science Laboratory, Migal Galilee Technological Center, Kiryat Shmona, Israel aut NATIONALLICENCE 700 1- Galili Gad Department of Plant Sciences, The Weizmann Institute of Science, 76100, Rechovot, Israel aut NATIONALLICENCE 700 1- Amir Rachel Plant Science Laboratory, Migal Galilee Technological Center, Kiryat Shmona, Israel aut NATIONALLICENCE 773 0- Plant Molecular Biology Kluwer Academic Publishers 61/1-2(2006-05-01), 255-268 0167-4412 61:1-2<255 2006 61 11103 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer