CAJ | 학술논문

细胞质型果糖1，6-二磷酸酶（cFBPase）是糖异生途径的主要限速酶，它除了主要参与蔗糖合成途径的调控外，对其他碳水化合物的合成与分配也产生一定影响．本文以坛紫菜（Pyropia haitanensis）转录组测序获得的 unigene 序列为基础，采用 cDNA 末端快速扩增（RACE）技术克隆了坛紫菜 cFBPase 基因序列，命名为 PhcFBPase（GenBank 收录号：KM434064）．序列分析结果表明，PhcFBPase 序列全长1406 bp，包含一个1101 bp 的开放阅读框，所编码的多肽包含366个氨基酸，分子量为39.1 kDa，等电点为5.42．基因表达水平的定量分析结果表明 PhcFBPase 基因在坛紫菜叶状体世代的表达水平显著高于丝状体世代，意味着坛紫菜生活史两个不同世代的光合固碳机制存在差异性；对坛紫菜叶状体进行高温胁迫不同时间水平，该基因的表达水平在胁迫初期表现为先上调表达，随着胁迫时间延长又开始下调表达，即在短时间的高温胁迫下，PhcFBPase 基因的表达有一个应激上调的过程，但长时间的高温胁迫则会抑制 Ph-cFBPase 基因的表达；不同失水胁迫条件下，PhcFBPase 基因的表达不受低水平的失水胁迫影响，但可被高水平（＞45％）的失水胁迫所抑制，并可在复水后迅速回升至正常水平．由此说明 PhcFBPase 基因在应答环境逆境胁迫时，没有发挥明显的主动拮抗作用，而只是被动的适应．
세포질형과당1，6-이린산매（cFBPase）시당이생도경적주요한속매，타제료주요삼여자당합성도경적조공외，대기타탄수화합물적합성여분배야산생일정영향．본문이단자채（Pyropia haitanensis）전록조측서획득적 unigene 서렬위기출，채용 cDNA 말단쾌속확증（RACE）기술극륭료단자채 cFBPase 기인서렬，명명위 PhcFBPase（GenBank 수록호：KM434064）．서렬분석결과표명，PhcFBPase 서렬전장1406 bp，포함일개1101 bp 적개방열독광，소편마적다태포함366개안기산，분자량위39.1 kDa，등전점위5.42．기인표체수평적정량분석결과표명 PhcFBPase 기인재단자채협상체세대적표체수평현저고우사상체세대，의미착단자채생활사량개불동세대적광합고탄궤제존재차이성；대단자채협상체진행고온협박불동시간수평，해기인적표체수평재협박초기표현위선상조표체，수착협박시간연장우개시하조표체，즉재단시간적고온협박하，PhcFBPase 기인적표체유일개응격상조적과정，단장시간적고온협박칙회억제 Ph-cFBPase 기인적표체；불동실수협박조건하，PhcFBPase 기인적표체불수저수평적실수협박영향，단가피고수평（＞45％）적실수협박소억제，병가재복수후신속회승지정상수평．유차설명 PhcFBPase 기인재응답배경역경협박시，몰유발휘명현적주동길항작용，이지시피동적괄응．
Cytosolic fructose-1,6-bisphosphatase (cFBPase),the key enzyme in the sucrose biosynthetic pathway, play important roles in carbon assimilation and metabolism.In this study,based on unigene sequences from whole transcriptome sequencing of Pyropia haitanensis,the full length of cFBPase,obtained by rapid amplification of cDNA ends (RACE)technology,was named as PhcFBPase(GenBank accession:KM434064).The full-length cDNA of the PhcFBPase gene comprised 1 406 nucleotides and contained an open reading frame of 1 101 bp,encoding a protein of 366 amino acid putative peptides residues with the predicted molecular weight of 39.1 KDa and theoretical isoelectric point of 5.42.The expression patterns of the PhcFBPase gene,as measured by real-time quantitative PCR,revealed that the expression of PhcFBPase gene in the thallus phase was significantly higher than in the conchocelis phase, which suggested that the different mechanisms of inorganic carbon utilization exist among the different life phase of P. haitanensis.During high-temperature stress,the expression levels of PhcFBPase significantly upregulated firstly and then decreased.However,the expression levels of PhcFBPase had no significantly change when the water loss was ≤45% during desiccation,but as the desiccation continue,the expression levels of PhcFBPase were significantly down-regulated.These results suggested that the PhcFBPase had no evident roles in response to high-temperature stress and extreme desiccation stress.