低温胁迫对菜用大豆生长、叶片活性氧及多胺代谢的影响

选用两种耐低温性不同的菜用大豆品种——‘沪宁95-1’(耐低温)和‘台湾75’(低温敏感),对低温胁迫下两者的生长、叶片活性氧及多胺代谢进行了比较。结果表明,低温胁迫后两者生物量积累显著受到抑制,但‘沪宁95-1’受抑制程度显著小于‘台湾75’；低温胁迫下两者叶片抗氧化酶活性、O·-2生成速率、H2O2和MDA含量均显著升高,但‘沪宁95-1’叶片抗氧化酶活性显著高于‘台湾75’,O·-2生成速率、H2O2和MDA含量则显著低于‘台湾75’；低温胁迫后‘沪宁95-1’叶片不同形态腐胺、亚精胺和精胺含量均显著上升,‘台湾75’叶片不同形态腐胺含量显著下降,游离态、结合态亚精胺和精胺含量显著上升,束缚态亚精胺和精胺含量变化不显著。以上结果表明,低温胁迫下不同形态腐胺、束缚态亚精胺和精胺与‘沪宁95-1’较低的生长抑制、较低的氧化损伤以及较高的保护酶活性有关,可能在菜用大豆耐寒性方面发挥重要作用。

Effects of chilling stress on growth,metabolism of reactive oxygen species and polyamines in vegetable soybean seedlings

Two vegetable soybean cultivars, Huning 95-1 (cold-tolerant cultivar) and Taiwan 75 (cold-sensitive cultivar) were used to investigate the effects of chilling stress on plant growth, metabolism of reactive oxygen species (ROS) and polyamines. The results showed that chilling stress significantly reduced the biomass production of both cultivars, with the reduction in Taiwan 75 more significant. When exposed to chilling stress, antioxidant enzymes activities, O·-2 producing rate, contents of hydrogen peroxide (H2O2) and malondiadehyde (MDA) increased significantly in both cultivars, with the fold of increment of antioxidant enzymes activities more significant in Huning 95-1 and O·-2production rate, contents of H2O2 and MDA in Taiwan 75, respectively. In addition, after chilling stress, contents of different forms of putrescine (Put), spermidine (Spd) and spermine (Spm) in leaves of Huning 95-1 increased significantly, contents of different forms of Put in leaves of Taiwan 75 decreased obviously, levels of free and conjugated Spd and Spm increased markedly, no significant difference was observed in bound Spd and Spm. These results indicated that different forms of Put, bound Spd and Spm were involved in lower growth reduction, lower oxidative damage and higher antioxidant enzymes activities in Huning 95-1, and they might play important roles in cold tolerance of vegetable soybean plants．