title: Enhanced susceptibility of photosynthesis to low-temperature photoinhibition due to interruption of chill-induced increase of S-adenosylmethionine decarboxylase activity in leaves of spinach (Spinacia oleracea L.).
abstract: The possible involvement of polyamines in the chilling tolerance of spinach (Spinacia oleracea L.) was investigated focusing on photosynthesis. During chilling at 8/5C (day/night) for 6 d, S-adenosylmethionine decarboxylase (SAMDC) activity increased significantly in leaves in parallel with the increase in putrescine and spermidine (Spd) content in leaves and chloroplasts. Treatment of leaves with methylglyoxal-bis(guanylhydrazone) (MGBG), an SAMDC inhibitor, resulted in the deterioration of plant growth and photosynthesis under chilling conditions, which was reversed by the concomitant treatment with Spd through the roots. Plants treated with MGBG showed lower photochemical efficiency of PSII than either the control or plants treated with MGBG plus Spd during chilling and even after transfer to warm conditions, suggesting an increase of photoinhibition due to low Spd in chloroplasts. Indeed, MGBG-treated plants had much lower activities of thylakoid electron transport and enzymes in carbon metabolism as well as higher degrees of lipid peroxidation of thylakoid membranes compared to the control. These results indicate that the enhanced activity of SAMDC with a consequential rise of Spd in chloroplasts is crucial for the cold acclimation of the photosynthetic apparatus in spinach leaves.
authors.affiliation: Department of Life Science, Faculty of Bioresources, Mie University, Tsu, 514-8507 Japan.
authors.forename: Lixiong
authors.initials: L
authors.lastname: He
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Nada
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Kasukabe
authors.forename: Shoji
authors.initials: S
authors.lastname: Tachibana
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D012437:Adenosylmethionine Decarboxylase / Q000235:genetics / Q000378:metabolism*; D002262:Carboxy-Lyases / Q000235:genetics / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism / Q000528:radiation effects; D002736:Chloroplasts / Q000378:metabolism; D003080:Cold Temperature; D004579:Electron Transport / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008027:Light; D045342:Light-Harvesting Protein Complexes; D015227:Lipid Peroxidation / Q000187:drug effects; D008935:Mitoguazone / Q000494:pharmacology; D010788:Photosynthesis / Q000502:physiology* / Q000528:radiation effects; D045322:Photosynthetic Reaction Center Complex Proteins / Q000187:drug effects; D018515:Plant Leaves / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D011073:Polyamines / Q000378:metabolism; D011700:Putrescine / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D013095:Spermidine / Q000378:metabolism; D018724:Spinacia oleracea / Q000201:enzymology* / Q000254:growth & development; D020524:Thylakoids / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects
chemical_list: D004791:Enzyme Inhibitors; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D011073:Polyamines; D012333:RNA, Messenger; D002734:Chlorophyll; D002262:Carboxy-Lyases; C019722:arginine decarboxylase; D012437:Adenosylmethionine Decarboxylase; D008935:Mitoguazone; D013095:Spermidine; D011700:Putrescine