低温对开花期水稻颖花保护酶活性和过氧化物积累的影响

Effect of Low Temperature on Protective Enzyme Activities and Hydrogen Peroxide Production in Spikelet of Rice at Flowering Stage

以耐冷性不同的水稻品种996和4628为材料,采用人工气候室进行低温(19℃(06:00-08:00;19:00-23:00)/21℃(08:00-10:00;16:00-19:00)/23℃(10:00-16:00)/17℃(23:00-06:00)和适温(24℃(06:00-8:00;19:00-23:00)/26℃(08:00-10:00;16:00-19:00)/30℃(10:00-16:00)/22℃(23:00-06:00))处理,研究了低温胁迫对水稻颖花中保护酶类活性和过氧化物积累的影响。结果表明,低温处理期间水稻颖花中超氧化物歧化酶(SOD),过氧化物酶(POX),过氧化氢酶(CAT)和抗坏血酸过氧化物酶(AsA-POX)活性呈先升后降趋势;随着低温处理时间延长,膜脂过氧化产物丙二醛(MDA)和过氧化氢(H2O2)含量迅速上升。低温胁迫后期,耐冷水稻品种996颖花中的H2O2和MDA含量显著低于冷敏感水稻品种4628,这可能与耐冷水稻品种996低温胁迫期间的保护酶类活性显著高于冷敏感水稻品种4628,其活性氧的产生和清除较均衡有关。

The experiments were carried out in growth chambers to investigate the effects of low temperature stress during flowering period on protective enzyme activities and hydrogen peroxide production of spikelet using two rice cultivars including low-temperature tolerant cultivar 996 and low-temperature sensitive cultivar 4628.Seven day/night two treatments of optimal temperature（24℃（06：00-8：00;19：00-23：00）/26℃（08：00-10：00;16：00-19：00）/30℃（10：00-16：00）/22℃（23：00-06：00）） and low temperature（19℃（06：00-8：00;19：00-23：00）/21℃（08：00-10：00;16：00-19：00）/23℃（10：00-16：00）/17℃（23：00-06：00）） after heading were established.The results showed that superoxide dismutase（SOD）,catalase（CAT）,peroxidase（POX） and ascorbic acid-peroxidase（AsA-POX） activcities in spikelet of rice increased obviously at early stage of low temperature stress,then decreased rapidly.The contents of malondialdehyde（MDA） and hydrogen peroxide（H2O2） were increased remarkably with the overtime of low temperature.The increase of MDA content and H2O2 content in the cultivar 4628 was greater than that in the cultivar 996,which may relation with protective enzyme activities in the cultivar 996 were higher than that in the cultivar 4628 under low temperature stress.The above results indicated that the reactive oxygen metabolism of the cultivar 996 was more balanced than that in the cultivar 4628 under low temperature stress.