亚精胺在缓解菜豆幼苗低温胁迫中的作用

为了研究外源亚精胺对菜豆幼苗耐低温性的影响。本研究以菜豆低温敏感型品种‘P16093’和耐低温型品种‘P16165’的幼苗为试验材料,设置常温对照(CK)、4℃低温(LT)以及4℃低温条件下喷施外源亚精胺(LT+Spd)3个处理组,对植株生长形态、抗氧化系统、渗透调节物质、生物膜、内源多胺含量进行测定。结果表明,低温条件下外源亚精胺的喷施能够促进植物生长,缓解低温对菜豆幼苗株高、茎粗、鲜重、干重的影响;与LT组相比喷施外源亚精胺使得低温下两品种幼苗叶片中电解质渗透率降低,最多下降了16.94%;丙二醛含量升高,在第8天分别上升了42.81%和70.59%;可溶性蛋白含量下降,脯氨酸含量上升;抗氧化酶活性升高;内源腐胺和亚精胺含量增加。研究结果表明外源亚精胺可以通过调控植物体内多胺代谢,增强ROS清除系统来缓解菜豆幼苗低温胁迫下受到的损伤。

Spermidine Alleviating Low Temperature Stress of Phaseolus vulgaris Seedlings

The aim is to study the effect of exogenous Spd on the tolerance of snap bean under low temperature. The seedlings of the low-temperature sensitive cultivar ‘P16093’ and the low-temperature tolerant cultivar ‘P16165’ were used as test materials, and three treatments were set up, including normal temperature control (CK), 4℃ low temperature treatment (LT) and 4℃ low temperature with spraying exogenous Spd (LT+Spd). The plant growth morphology, antioxidant system, osmotic adjustment substance, biofilm and endogenous polyamine content were measured in the three treatments. The results showed that the spraying of exogenous Spd at low temperature promoted plant growth and alleviated the effects of low temperature on plant height, stem thickness, fresh weight and dry weight of snap bean seedlings; the spraying of exogenous Spd reduced the electrolyte permeability in the seedlings’ leaves of both varieties at low temperature compared with the LT group with a maximum decrease of 16.94%. The malondialdehyde content of the two varieties increased, rising by 42.81% and 70.59% on the 8^th day, respectively. The soluble protein content decreased while the proline content increased; the antioxidant enzyme activity increased, as well as the endogenous Put and Spd content. The results indicate that the exogenous Spd could alleviate the damage of snap bean seedlings under low temperature stress by regulating polyamine metabolism and enhancing ROS scavenging system in plants.