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Biomedical subjects

T M Ching

Publications and source records attributed to T M Ching.

28 records · Page 2Linked to original sources
PubMed1970

Glyoxysomes in megagamethophyte of germinating ponderosa pine seeds.

Decoated ponderosa pine (Pinus ponderosa Laws) seeds contained 40% lipids, which were mainly stored in megagametophytic tissue and were utilized or converted to sugars via the glyoxylate cycle during germination. Mitochondria and glyoxysomes were isolated from the tissue by sucrose density gradient centrifugation at different stages of germination. It was found that isocitrate lyase, malate synthase, and catalase were mainly bound in glyoxysomes. Aconitase and fumarase were chiefly localized in mitochondria, whereas citrate synthase was common for both. Both organelles increased in quantity and specific activity of their respective marker enzymes with the advancement of germination. When the megagametophyte was exhausted at the end of germination, the quantity of these organelles and the activity of their marker enzymes decreased abruptly. At the stage of highest lipolysis, the isolated mitochondria and glyoxysomes were able to synthesize protein from labeled amino acids. Both organellar fractions contained RNA and DNA. Some degree of autonomy in glyoxysomes is indicated.

Journal Article↗
PubMed1966

Compositional changes of douglas fir seeds during germination.

Changes in weight, water content, nucleic acids, nucleotides, carbohydrates, lipids, nitrogenous and phosphorus compounds in embryo and gametophyte of Douglas fir seeds (Pseudotsuga menziesii Franco) were studied at 6 stages of germination. Lipids, proteins, and reserve phosphorus compounds in the gametophyte were utilized for the synthesis of carbohydrates, structural components, and soluble compounds in the seedling.The general quantitative metabolic changes that occur during germination of Douglas fir seeds are comparable to those known for angiosperm seeds.

Journal Article↗