杉木苯丙氨酸解氨酶基因ClPAL的克隆与表达分析  

Isolation and Expression of ClPAL Genes in Chinese Fir(Cunninghamia lanceolata)

作　　者：徐莉莉[1] 童再康[1] 林二培[1] 黄华宏[1] 

机构地区：[1]浙江农林大学亚热带森林培育国家重点实验室培育基地,临安311300

出　　处：《林业科学》2013年第12期64-72,共9页Scientia Silvae Sinicae

基　　金：国家863项目(2011AA100203);浙江省农业科技重点项目(2012C12908-11;2011C12014;2009R50035);浙江农林大学研究生科研创新基金项目(3122013240137)

摘　　要：利用RACE方法从杉木中分离得到3个编码苯丙氨酸解氨酶(PAL)的全长cDNA序列,分别为2 455,2 418,2 689 bp,编码的氨基酸个数分别为709,710,709。氨基酸序列分析显示,推导的氨基酸序列包含PAL-HAL和PAL 2个功能域以及酶活性中心序列(GTITASGDLVPLSYIA)。荧光定量PCR分析表明,虽然3个ClPAL基因在调查的器官和组织中皆有表达,但仍表现出一定的组织特异性。ClPAL1在木质化茎中的表达量明显高于针叶、雌球花、根和非木质化茎中的表达量,ClPAL3主要在木质化茎中表达;二者均在木质部中优势表达,且在中间材中的表达量高出边材20倍以上。ClPAL2主要在富含韧皮部针叶和皮层中高丰度表达。IAA、GA3和BR能促进木质部细胞的分化,与木质素的生物合成有直接或间接的联系。经此3种激素处理后,ClPAL1和ClPAL3的表达模式相似,均受到不同程度的诱导,其中IAA和BR的诱导效应相对明显;ClPAL2基因的表达则受到相对弱的抑制。这些结果说明ClPAL1和ClPAL3可能主要参与了杉木木材中木质素的合成过程。在应压木诱导形成中,ClPAL1在应压区木质部的表达量表现为先下降后上升,处理10天后达对照的1.4倍,在对应区木质部中则呈现下调表达;ClPAL2在应压区木质部中表现为上调表达,而在对应区木质部中,仅处理10天后的表达量明显高于对照;ClPAL3的表达量变化不是很明显。另外,ClPAL2基因在中间材中的表达丰度也明显高于边材,是否参与杉木心材特殊色泽的形成值得深入研究。In this study, three full-length cDNAs encoding phenylalanine ammonia lyase （PAL） were isolated from Chinese Fir （Cunninghamia lanceolata） using RACE. They encode 709, 710 and 709 amino acids, respectively, and their sequence lengths are 2 455, 2 418 and 2 689 bp, respectively. The amino acid sequences contain two functional domains of PAL-HAL and PAL, and the enzyme active site （GTITASGDLVPLSYIA）. The expression analysis showed that the three CIPALs differentially expressed in different organs. The expression level of ClPAL1 in lignified stem was higher than that in needle, male cone, root and non-lignified stem, and ClPAL3 was mainly expressed in lignified stem. Both genes were predominantly expressed in xylem, and their expression levels in intermediate wood were over 20 times higher than that in sapwood. ClPAL2 exhibited the high transcript abundance in phloem-enriched needles and bark. IAA, GA3 and BR can promote the differentiation of xylem cells, and thus they should directly or indirectly associate with lignin biosynthesis. After application of the three hormones, ClPAL1 and ClPAL3 were induced to different extents, and changes in the expressions were relatively more significant with IAA and BR, indicating that ClPAL1 and C1PAL3 were likely to play important roles in lignin biosynthesis of Chinese Fir wood tissue. During the compression wood formation, the expression level of ClPAL1 in the compression area of xylem showed decreased then increased, and reached to 1.4 times of the control level after 10 days bending treatment. Its expression levels in the opposite area of the compressed zone were lower than that of the control. The ClPAL2 expression was up-regulated in the compression wood, and its value in the opposite wood area was obviously higher than that of the control after 10 days bending. The expression changes of ClPAL3 were not significant compared with the control. In addition, the expression level of the C1PAL2 in intermediate wood washigher than that in sapwood. It deserves further

关 键 词：杉木 PAL基因 基因克隆 基因表达 木材形成 

分 类 号：S718.46[农业科学—林学] Q943.2[生物学—植物学]