24-表油菜素内酯对海洋红藻龙须菜琼胶合成及其相关基因表达的影响  

Effects of 24-epibrassinolide on the agar synthesis and expression of genes involved in marine alga Gracilariopsis lemaneiformis

作　　者：汤小彬 徐年军[1,2] 孙雪[1,2] 李亚鹤[1,2] 张琳[1,2] 

机构地区：[1]宁波大学应用海洋生物技术教育部重点实验室,浙江宁波315211 [2]宁波大学海洋学院,浙江省海洋生物工程重点实验室,浙江宁波315211

出　　处：《水产学报》2015年第12期1788-1798,共11页Journal of Fisheries of China

基　　金：国家自然科学基金(31072229,41376151)~~

摘　　要：为了探讨外源24-表油菜素内酯(24-epi BL)对不同温度下龙须菜生长及琼胶含量的影响,并揭示琼胶含量与葡萄糖磷酸变位酶基因(pgm)和甘露糖磷酸变位酶基因(pmm)表达量之间的关系,研究了不同浓度24-epi BL对3种温度培养条件下龙须菜的生长、琼胶含量及2种琼胶合成相关基因表达的影响。结果显示在15和31℃培养时,添加0.1 mg/L的24-epi BL时龙须菜相对生长速率最高,分别为9.22%/d和11.73%/d;而在25℃培养时,0.5 mg/L的24-epi BL对龙须菜生长促进作用最强,相对生长速率为14.98%/d;在15℃培养时,0.5 mg/L的24-epi BL添加后琼胶含量最高,为7.76%;而25和31℃时则是1.0 mg/L的24-epi BL添加后琼胶含量最高,分别为9.82%和6.60%。本研究还扩增得到了分别编码585和249个氨基酸的pgm和pmm基因,这2条基因都与皱波角叉菜的相应基因相似性最高;利用实时荧光定量PCR检测pmm和pgm基因的相对表达量,结果显示在15℃时,24-epi BL浓度为0.5 mg/L时pgm表达量最高,为对照组的1.72倍;在25和31℃时,24-epi BL浓度为1.0 mg/L时pgm表达量最高,分别为对照组的2.38倍和1.51倍;而3种温度培养下24-epi BL对pmm基因的表达也具有一定的促进作用。研究表明,一定浓度的24-epi BL能促进龙须菜的生长和琼胶合成,并且pgm基因的表达量与琼胶含量密切相关,能在一定程度上指示琼胶含量的高低。The effects of 24-epibrassinolide on the expression level of two genes,pgm encoding phosphoglucomutase（ PGM） and pmm encoding phosphomannomutase（ PM M）,involved in agar synthesis at different temperatures as well as the correlation between genes expression level and agar content were investigated in marine red alga G racilariopsis lemaneiformis 981 strain. The open reading frames（ ORF） of pgm and pmm were obtained by PCR,encoding 585 amino acids and 249 amino acids,respectively. The deduced amino acid sequences showed significant similarity to the pgm and pmm sequences of Chondrus crispus. Real time quantitative PCR technique was used to detect the relative expression levels of PGM and PM M. Results showed that the highest growth rate of G. lemaneiformis was observed under the treatment of 0.1mg / L 24-epibrassinolide at 15 and 31 ℃,while the highest growth rate was at 0.5 mg/L 24-epibrassinolide treatment group at 25 ℃. The agar content and pgm expression of G. lemaneiformis were the highest at 0.5 mg/L 24-epibrassinolide treatment group at 15 ℃,and those of G. lemaneiformis was higher than the control and other treated groups when treated at 1.0 mg/L 24-epibrassinolide at 25 and 31 ℃.Besides,24-epibrassinolide could also improve pmm expression level at different temperatures. The results indicated that 24-epibrassinolide can improve the growth and agar synthesis of G. lemaneiformis,and pgm expression level is closely related with agar content,which may be useful in screening for high-agar-content strains.

关 键 词：龙须菜 24-表油菜素内酯 生长 琼胶 基因表达量 

分 类 号：Q785[生物学—分子生物学] S968.4[农业科学—水产养殖]