摘要
以玉米耐寒自交系黄C和低温敏感自交系Mo17为材料,研究了亚精胺(Spd)和精胺(Spm)引发对玉米种子吸胀中的耐冷性和种子发芽能力的影响。种子经0.25mmolL-1的Spd和Spm引发72h后,在5℃下低温吸胀不同时间(12、24、36和48h)。结果表明,Spd和Spm引发提高了胁迫期间两自交系胚内过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)和抗坏血酸过氧化物酶(APX)活性,以及可溶性蛋白质和脯氨酸(Pro)含量,降低了胚渗出液的核苷酸含量,同时显著提高发芽率,并显著缩短平均发芽时间。低温吸胀48h后,与对照相比,Spd和Spm处理分别提高两自交系种子的平均发芽率18.5%和14.0%,分别缩短平均发芽时间1.21d和1.14d。黄C在种子吸胀期间的耐冷性强于Mo17。总之,Spd和Spm处理能提高玉米种子吸胀期间的耐冷性,提高低温胁迫下种子发芽能力。
Chilling injury caused by low temperature happens frequently during seed imbibition in maize （Zea mays L.）. Polyamines （PAs） such as putrescine （Put）, spermindine （Spd）, and spermine （Spm） are accumulated in plants, maintaining the stability and integrality of membrane under low temperature stress and eliminating free radicals in cells. They have been used by presoaking and leaf spray in barley （Hordeum vulgare L.） and wheat （Triticum aestivum L.） respectively to improve the tolerance to abiotic stresses. In the present study, Spd and Spm were used as an inducer to investigate chilling tolerance during seed imbibition and seed germination in maize. Seeds of maize inbred lines ‘Hung C＇ （chilling-tolerant） and ‘Mo17＇ （chilling-sensitive） were soaked with 0.25 mmol L^-1 of Spd and Spm, respectively for 72 h under dark at 15℃, and the control was not treated with PAs. Part of the seeds were germinated for 7 d under 25℃ after imbibition for 48 h under 5℃ in dark. The germination rates were tested every day with 4 replicates （25 seeds per replicate） each. Other part of seeds were imbibed for 0, 12, 24, 36, and 48 h, respectively at 5℃ in dark. The embryos were separated from the seeds for testing the activities of peroxidase （POD）, catalase （CAT）, superoxide dismutase （SOD） and ascorbate peroxidese （APX） as well as the contents of proline （Pro）, soluble protein, and nucleic acid in embryo leakage. All measurements repeated 3 times with 15 seeds each time. Under chilling stress, both Spd and Spm treatments increased the activities of POD, CAT, SOD, and APX, raised soluble protein and Pro contents, and reduced nu- cleic acid content in embryo leakage. The treatments also increased seed germination percentage and shortened the mean germina- tion time （MGT） which increased by 18.5% and 14.0%, and decreased by 1.21 d and 1.14 d for Spd and Spm treatments, respectively as compared with those of control. During the imbibition under chilling stress, the activities of POD, CAT, SOD and APX, Pro and soluble protein contents in embryos and germination percentage were higher, whereas the content of nucleic acid and MGT were lower in untreated Huang C seeds than in untreated Mo17 seeds. The results suggested that Spd and Spm treatments can improve the chilling tolerance during seed imbibition, and enhance the germination of maize seeds.
出处
《作物学报》
CAS
CSCD
北大核心
2008年第2期261-267,共7页
Acta Agronomica Sinica
基金
国家自然科学基金项目(30370911)
关键词
多胺
玉米自交系
低温胁迫
吸胀
抗氧化酶
发芽
Polyamines
Maize inbred line
Chilling stress
Imbitition
Antioxidant enzyme
Germination
