title: Effects of moist cold stratification on germination, plant growth regulators, metabolites and embryo ultrastructure in seeds of Acer morrisonense (Sapindaceae).
abstract: Breaking of seed dormancy by moist cold stratification involves complex interactions in cells. To assess the effect of moist cold stratification on dormancy break in seeds of Acer morrisonense, we monitored percentages and rates of germination and changes in plant growth regulators, sugars, amino acids and embryo ultrastructure after various periods of cold stratification. Fresh seeds incubated at 25/15 °C for 24 weeks germinated to 61%, while those cold stratified at 5 °C for 12 weeks germinated to 87% in 1 week. Neither exogenous GA3 nor GA4 pretreatment significantly increased final seed germination percentage. Total ABA content of seeds cold stratified for 12 weeks was reduced about 3.3-fold, to a concentration similar to that in germinated seeds (radicle emergence). Endogenous GA3 and GA7 were detected in 8-week and 12-week cold stratified seeds but not in fresh seeds. Numerous protein and lipid bodies were present in the plumule, first true leaves and cotyledons of fresh seeds. Protein and lipid bodies decreased greatly during cold stratification, and concentrations of total soluble sugars and amino acids increased. The major non-polar sugars in fresh seeds were sucrose and fructose, but sucrose increased and fructose decreased significantly during cold stratification. The major free amino acids were proline and tryptophan in fresh seeds, and proline increased and tryptophan decreased during cold stratification. Thus, as dormancy break occurs during cold stratification seeds of A. morrisonense undergo changes in plant growth regulators, proteins, lipids, sugars, amino acids and cell ultrastructure.
authors.affiliation: Division of Silviculture, Taiwan Forestry Research Institute, 53 Nan-Hai Road, Taipei 10066, Taiwan.
authors.forename: Shun-Ying
authors.initials: SY
authors.lastname: Chen
authors.affiliation: Division of Silviculture, Taiwan Forestry Research Institute, 53 Nan-Hai Road, Taipei 10066, Taiwan.
authors.forename: Shih-Han
authors.initials: SH
authors.lastname: Chou
authors.affiliation: Institute of Ecology and Evolutionary Biology, College of Life Science, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Ching-Chu
authors.initials: CC
authors.lastname: Tsai
authors.affiliation: Division of Silviculture, Taiwan Forestry Research Institute, 53 Nan-Hai Road, Taipei 10066, Taiwan.
authors.forename: Wen-Yu
authors.initials: WY
authors.lastname: Hsu
authors.affiliation: Department of Biology, University of Kentucky, Lexington, KY 40506, USA; Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546, USA.
authors.forename: Carol C
authors.initials: CC
authors.lastname: Baskin
authors.affiliation: Department of Biology, University of Kentucky, Lexington, KY 40506, USA.
authors.forename: Jerry M
authors.initials: JM
authors.lastname: Baskin
authors.affiliation: Division of Silviculture, Taiwan Forestry Research Institute, 53 Nan-Hai Road, Taipei 10066, Taiwan. Electronic address: chingtechien@gmail.com.
authors.forename: Ching-Te
authors.initials: CT
authors.lastname: Chien
authors.affiliation: Institute of Ecology and Evolutionary Biology, College of Life Science, National Taiwan University, Taipei 10617, Taiwan. Electronic address: linglong@ntu.edu.tw.
authors.forename: Ling-Long
authors.initials: LL
authors.lastname: Kuo-Huang
mesh_terms: D031002:Acer / Q000378:metabolism / Q000648:ultrastructure; D003080:Cold Temperature; D018525:Germination; D010937:Plant Growth Regulators / Q000378:metabolism*; D012639:Seeds / Q000378:metabolism / Q000648:ultrastructure; D013997:Time Factors
chemical_list: D010937:Plant Growth Regulators
keywords: Acer; Amino acids; Cold stratification; Embryo ultrastructure; Plant growth regulators; Seed dormancy; Seed germination; Sugars