琼胶寡糖聚合度对坛紫菜抗性诱导的影响  

Effects of degree of polymerization of oligoagars on inducing the defense response in Porphyra haitanensis(Rhodophyta)

作　　者：朱竹君[1] 骆其君[1] 严小军[1] 杨锐[1] 何山[1] 陈海敏[1] 

机构地区：[1]宁波大学海洋生物工程重点实验室,应用海洋生物技术教育部重点实验室,浙江宁波315211

出　　处：《海洋学报》2012年第6期205-209,共5页

基　　金：宁波市创新团队(2011B81007);宁波市科技计划项目(201201C1011016);浙江省自然科学基金(Y5100066);国家自然科学基金(40776077)

摘　　要：研究了琼胶寡糖聚合度对坛紫菜抗性诱导的效应。以琼胶3,6和12糖,3种聚合度的琼胶寡糖为材料,处理坛紫菜,通过观察叶片腐烂率比较坛紫菜生长状态;利用透射电镜观察处理后的细胞亚显微结构变化;并检测坛紫菜附生菌的数量变化;以对羟基苯乙酸(POHPAA)化学发光法检测坛紫菜H2O2释放量;利用实时定量PCR检测坛紫菜NADPH氧化酶基因(Phrboh)的差异表达。结果表明,经琼胶3糖和6糖处理,坛紫菜的Phboh表达出现上调,并产生H2O2暴发。经两种琼胶寡糖处理后,坛紫菜的附生菌数量明显减少,其中以琼胶6糖的效果最好,在较长培养时间内,坛紫菜能保护自身细胞亚显微结构的完整性,维持良好的生长状态。而琼胶12糖没发现任何诱导作用。综上所述,聚合度为3和6的琼胶寡糖能诱导坛紫菜的抗性响应,特别是形成单个螺旋结构的琼胶6糖的诱导作用最明显,但聚合度较大的琼胶寡糖则不能。The defense responses of Porphyra haitanensis to oligoagars with different degree of polymeriza- tions （DP） were investigated. Oligoagars with three different DPs （agartirose, hexaose and dodeeaose） were used to evaluate the effect of structure of oligosaccharides on inducing the defense response in P. hai- tanensis. After elicited with 100 μg/ml oligoagars, the growing status of P. haitanensis gametophyte was observed by microscope and ultrastructure examination. The impact of the algal response to oligoagars on the epiphytic bacteria was determined by examing the numbers of associated bacteria. The expression level of NADPH oxidase （named Phrboh） was detected by real-time PCR. The concentration of H2O2 in the me- dium was determined by measuring the dimerization of （p-hydroxyphenyl） acetic acid. Results indicated that P. haitanensis responded with an oxidative burst and rapid increases in Phrboh expression when agar- otriose and agarohexaose were added to the growth medium. Further, elicitation of P. haitanensis with these two oligoagars caused elimination of epiphytic bacteria. The rot of thallus was lightened and cells of P. haitanensis kept well status in the four days culture. In them, agarohexaose showed stronger effects. Agarhexaose elicited a release of hydrogen peroxide in less than 15 min. The expression of Pyrboh was up- regulated in five minutes and 16.5 fold increases in the expression were observed 5 min after addition of agarohexaose. In contrast, agarododecaose did not have any effect. In summary, P. haitanensis respond immediately after exposure to agarotriose and agarohexaose with a variety of physiological changes, espe- cially agarhexaose could elicit strongest response to P. haitanensis. Oligoagars with high degree of poly- merization showed no effect.

关 键 词：坛紫菜 琼胶寡糖 聚合度 抗性响应 

分 类 号：Q814[生物学—生物工程]