Browsing by Author "Chien, Ching-Te"

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Dormancy-break and germination in seeds of Prunus campanulata (Rosaceae): role of covering layers and changes in concentration of abscisic acid and gibberellins
(2007-03-01)
Chen, Shun-Ying
;
Chien, Ching-Te
;
Chung, Jeng-Der
;
Yang, Yuh-Shyong
;
Kuo, Shing-Rong
Intact seeds (seed + endocarp) from freshly harvested fruits of Prunus campanulata were dormant, and required 4-6 weeks of warm followed by 8 weeks of cold stratification for maximum germination percentage. Removing both endocarp and seed coat, however, promoted germination in a high percentage of non-stratified seeds. Treatment of intact, non-stratified seeds with gibberellic acid (GA(3)) was only partially effective in breaking dormancy. However, GA(3) promoted germination of non-stratified seeds in which the endocarp (but not the seed coat) had been removed. The order of abscisic acid (ABA) concentration in fresh seeds was endocarp > seed coat > embryo, and its concentration in endocarp plus seed coat was about 6.2-fold higher than that in the embryo. Total ABA contents of seeds subjected to warm and/or cold moist stratification were reduced 6- to 12-fold. A higher concentration of GA(4) was detected in embryos of non-dormant than in those of dormant seeds. Fluridone, a carotenoid biosynthesis inhibitor, was efficient in breaking dormancy of Prunus seeds. Paclobutrazol, a GA biosynthesis inhibitor, completely inhibited seed germination, and the inhibitory effect could be partially reversed by GA(4), but not by GA(3) Thus, dormancy in P campanulata seeds is imposed by the covering layers. Dormancy break is accompanied by a decrease in ABA content of the covering layers and germination by an increase of embryonic GA(4) content.
Protein changes between dormant and dormancy-broken seeds of Prunus campanulatal Maxim
(2006-07-01)
Lee, Chung-Shu
;
Chien, Ching-Te
;
Lin, Chao-Hsiung
;
Chiu, Yi-Ying
;
Yang, Yuh-Shyong
Seed dormancy is regulated by complex networks in order to optimize the timing of germination. However, the biochemical basis of the regulation of seed dormancy is still poorly understood. Many temperate timber species, which are of ecological and/or economic interest, are deeply dormant in seeds, such as Prunus campanulata. Freshly harvested seeds require warm plus cold stratification to break dormancy before they can begin to germinate. According to the results of germination, both warm and cold stratifications are the critical influences for breaking seed dormancy. Significant variations in seed proteins were observed by 2-DE before and after the breaking of seed dormancy. Among the 320, 455, and 491 reproducibly detected spots on the cotyledons, embryos, and testae, respectively, 71 dramatic changes in abundances were observed following warm and/or cold stratification. Among these protein spots, dehydrin, prunin 1 precursor, prunin 2 precursor, and prunin 2 were identified by MS and sequence comparison. The implications of protein changes in relation to the breaking of seed dormancy and germination are discussed. This is the first report of a proteomic analysis of dormancy breaking in woody plant seeds.