title: Oligogalacturonic acids promote tomato fruit ripening through the regulation of 1-aminocyclopropane-1-carboxylic acid synthesis at the transcriptional and post-translational levels.
abstract: BACKGROUND
  Oligogalacturonic acids (OGs) are oligomers of alpha-1,4-linked galacturonosyl residues that are released from cell walls by the hydrolysis of polygalacturonic acids upon fruit ripening and under abiotic/biotic stress. OGs may induce ethylene production and fruit ripening, however, the mechanism(s) behind these processes is unknown.
  
  
  RESULTS
  Tomato cultivar 'Ailsa Craig' (AC) and mutant Neverripe, ripening inhibitor, non-ripening, and colorless non-ripening fruits were treated with OGs at different stages. Only AC fruits at mature green stage 1 showed an advanced ripening phenomenon, although transient ethylene production was detected in all of the tomato fruits. Ethylene synthesis genes LeACS2 and LeACO1 were rapidly up-regulated, and the phosphorylated LeACS2 protein was detected after OGs treatment. Protein kinase/phosphatase inhibitors significantly affected the ripening process induced by the OGs. As a potential receptor of OGs, LeWAKL2 was also up-regulated in their presence.
  
  
  CONCLUSIONS
  We demonstrated that OGs promoted tomato fruit ripening by inducing ethylene synthesis through the regulation of LeACS2 at transcriptional and post-translational levels.
authors.affiliation: College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, People's Republic of China. mayingxuan@cau.edu.cn.
authors.forename: Yingxuan
authors.initials: Y
authors.lastname: Ma
authors.affiliation: College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, People's Republic of China. 1696298378@qq.com.
authors.forename: Leilei
authors.initials: L
authors.lastname: Zhou
authors.affiliation: College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, People's Republic of China. 879402585@qq.com.
authors.forename: Zhichao
authors.initials: Z
authors.lastname: Wang
authors.affiliation: College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, People's Republic of China. 125600733@qq.com.
authors.forename: Jianting
authors.initials: J
authors.lastname: Chen
authors.affiliation: College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, People's Republic of China. quguiqin2000@sina.com.
authors.forename: Guiqin
authors.initials: G
authors.lastname: Qu
mesh_terms: D000598:Amino Acids, Cyclic / Q000096:biosynthesis*; D005030:Ethylenes / Q000096:biosynthesis; D005638:Fruit / Q000254:growth & development*; D008190:Lyases / Q000235:genetics; D018551:Solanum lycopersicum / Q000235:genetics* / Q000378:metabolism; D009844:Oligosaccharides / Q000502:physiology*; D014158:Transcription, Genetic
chemical_list: D000598:Amino Acids, Cyclic; D005030:Ethylenes; D009844:Oligosaccharides; C412763:oligogalacturonic acid; C023863:1-aminocyclopropane-1-carboxylic acid; C036216:ethylene; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase