温度对甜菜种子萌发速率和线粒体活性的影响

研究了不同温度对甜菜种子萌发速率和线粒体活性的影响。在 7,14和 2 0℃中甜菜种子萌发 5 0 %需要的时间分别是 7,3和 2 3d ;萌发 5 0 %的热时间大约是 46℃·d。在 7,14和 2 0℃萌发的种子和幼苗的线粒体中 ,总蛋白含量以及细胞色素氧化酶 (CCO)和苹果酸脱氢酶 (MDH)的活性随着萌发进程增加 ;相对分子质量大约为 1880 0 ,35 0 0 0和 36 0 0 0的蛋白质随着萌发进程降低 ;相对分子质量大约为 2 2 0 0 0的蛋白质在 7℃中逐渐增加 ,在 14和 2 0℃中则先少量增加然后下降。 2 0℃中萌发的种子和幼苗的线粒体的CCO和MDH的比活性和总活性比在 7和 14℃中高。这些结果表明 ,萌发温度显著地影响种子的萌发速率、线粒体的CCO和MDH活性以及较小相对分子质量热休克蛋白 2 2

Effects of Temperature on Germination Rate and Mitochondrial Activity in Beta vulgaris L.Seeds

Effects of different temperature on germination rate and mitochondrial activity during germination of Beta vulgaris L.seeds were studied. The times required for 50% germination were 7 d at 7 ℃, 3 d at 14 ℃ and 2.3 d at 20 ℃, respectively. The thermal times for 50% of germination were about 46 degree days (℃*d). The content of total proteins and activities of cytochrome coxidase(CCO) and malate dehydrogenase (MDH) in mitochondria from seeds and seedlings germinated at 7, 14 and 20 ℃ progressively increased with germination; and specific and total activities of CCO and MDH at 20 ℃ were higher than those at 7 and 14 ℃. Proteins with approximate Mw of \{36 000,\} 35 000 and 18 800 in mitochondria from seeds and seedlings germinated at 7, 14 and 20 ℃ gradually decreased with germination, 22 000 proteins in mitochondria progressively increased at 7 ℃, and slightly increased from 0 d of germination to 4 d(14 ℃) and 3 d(20 ℃), and then declined. These results showed that germination rate of seeds, activities of CCO and MDH and lmw proteins in mitochondria were significantly affected by germination temperature.