摘要
莲种子具有抗超高温的能力 ,在 10 0℃保温 2 4h仍然保持 10 0 %的发芽率 ,萌发后能长出外观正常的幼苗 ,但种子活力则较大幅度的下降。莲子在 110℃下保温 2 4h后还保持 4 0 %的发芽率 ,但萌发时由于子叶腐烂而不能成苗。莲种子发育过程中 ,胚轴超氧化物歧化酶 (SOD)、过氧化物酶 (POD)活性不断升高 ;胚轴过氧化氢酶 (CAT)活性在 2 0DAP达到最高 ,随后下降 ;胚轴中抗坏血酸从发育初期直至完全成熟期持续积累 ,直到完全成熟期。胚轴酶提取液经 10 0℃煮 5min后 ,CAT和POD的活性全部丧失 ,而SOD活性仍很高 ,经 10 0℃煮 6 0min后SOD原有活性只丧失 1/
Lotus( Nelumbo nucifera Gaertn.) seeds are very peculiar in having extremely long life span. They are usually called 'wonderful seeds' or 'long living seeds'. Lotus seeds had an unusually strong heat resistance. One hundred percentage of germination in fully matured lotus seeds was obtained after treatment at 100℃ for 24 h in air oven, the aged seeds could develop into the normal seedlings after germination, but the seed vigor declined to a low level. Forty percentage of germination was got after treatment at 110℃ for 24 h in an air oven, however the seedlings could not further grow because the cotyledons rotted after germination (Fig.1 and Fig.2). According to seed growth, dry matter accumulation(Fig.3) and seed vigor formation(Fig.4), the development and maturation of lotus seeds could be divided into three stages: tissue differentiation (0-13 day after pollination, DAP), storage matter accumulation (14-20 DAP) and desiccation maturation stage( 21-30 DAP). During lotus seed development, the activities of peroxidase (POD) and superoxide dismutase (SOD) in axes increased and reached their maximum at full maturation stage; The activities of catalase(CAT) in lotus axes reached its maximum on 20 DAP, and then declined(Fig.5). Ascorbate in lotus axes accumulated during seed development and its content reached maximum at full maturation stage(Fig.6). Both CAT and POD lost their activities when the enzyme extracts were placed in boiling water for 5 min. However, 66% of the SOD activity remained after the enzyme extract was incubated in boiling water for 60 min (Fig.7). The possible physiological and molecular basis of long life span in lotus seeds was discussed.
出处
《植物生理与分子生物学学报》
CAS
CSCD
2003年第5期421-424,共4页
Journal Of Plant Physiology and Molecular Biology
基金
国家留学回国人员科研启动基金项目资助
关键词
莲
种子发育
抗氧化酶
耐热性
lotus
seed development
antioxidative enzyme
thermotolerance
