植物学报
植物學報
식물학보
ACTA BOTANICA SINICA
2002年
12期
1456-1461
,共6页
肌动蛋白%3′端非翻译区%差异表达%分子进化%豌豆
肌動蛋白%3′耑非翻譯區%差異錶達%分子進化%豌豆
기동단백%3′단비번역구%차이표체%분자진화%완두
actin%3′-untranslated region (3′-UTR)%differential expression%molecular evolution%pea (Pisum sativum)
豌豆(Pisum sativum Linn.)肌动蛋白基因至少可以分为3类异型体: PEAcⅠ、PEAcⅡ和PEAcⅢ,它们的编码区序列相似性很高,而非编码区序列存在显著的差异.RT-PCR和以3′端非翻译区作探针的Southern杂交结果显示豌豆肌动蛋白异型体基因在根、茎、叶、卷须、花粉和幼嫩果实中均表达,但表达强度存在明显差异.利用连续稀释电泳对PEAcⅠ的转录本水平进行分析后发现它倾向于在幼嫩的器官中表达,且在7 d的茎中表达最强;在一个月内的叶片中表达也较强,此后明显下降;卷须中表达变化不显著,在花粉中表达很弱,在幼嫩荚果中的表达亦较多.PEAcⅡ表达特点与PEAcⅠ具有某些相似性.根据肌动蛋白序列重建的系统发生树表明豌豆肌动蛋白3类异型体间的分歧明显,但起源于单、双子叶植物分化前的共同基因祖先.推测豌豆肌动蛋白异型体基因在转录调控和细胞功能上存在差异.
豌豆(Pisum sativum Linn.)肌動蛋白基因至少可以分為3類異型體: PEAcⅠ、PEAcⅡ和PEAcⅢ,它們的編碼區序列相似性很高,而非編碼區序列存在顯著的差異.RT-PCR和以3′耑非翻譯區作探針的Southern雜交結果顯示豌豆肌動蛋白異型體基因在根、莖、葉、捲鬚、花粉和幼嫩果實中均錶達,但錶達彊度存在明顯差異.利用連續稀釋電泳對PEAcⅠ的轉錄本水平進行分析後髮現它傾嚮于在幼嫩的器官中錶達,且在7 d的莖中錶達最彊;在一箇月內的葉片中錶達也較彊,此後明顯下降;捲鬚中錶達變化不顯著,在花粉中錶達很弱,在幼嫩莢果中的錶達亦較多.PEAcⅡ錶達特點與PEAcⅠ具有某些相似性.根據肌動蛋白序列重建的繫統髮生樹錶明豌豆肌動蛋白3類異型體間的分歧明顯,但起源于單、雙子葉植物分化前的共同基因祖先.推測豌豆肌動蛋白異型體基因在轉錄調控和細胞功能上存在差異.
완두(Pisum sativum Linn.)기동단백기인지소가이분위3류이형체: PEAcⅠ、PEAcⅡ화PEAcⅢ,타문적편마구서렬상사성흔고,이비편마구서렬존재현저적차이.RT-PCR화이3′단비번역구작탐침적Southern잡교결과현시완두기동단백이형체기인재근、경、협、권수、화분화유눈과실중균표체,단표체강도존재명현차이.이용련속희석전영대PEAcⅠ적전록본수평진행분석후발현타경향우재유눈적기관중표체,차재7 d적경중표체최강;재일개월내적협편중표체야교강,차후명현하강;권수중표체변화불현저,재화분중표체흔약,재유눈협과중적표체역교다.PEAcⅡ표체특점여PEAcⅠ구유모사상사성.근거기동단백서렬중건적계통발생수표명완두기동단백3류이형체간적분기명현,단기원우단、쌍자협식물분화전적공동기인조선.추측완두기동단백이형체기인재전록조공화세포공능상존재차이.
Pea (Pisum sativum Linn.) actin gene family contains at least three isoforms (PEAcⅠ, PEAcⅡand PEAcⅢ), and the DNA sequence of these isoforms show high similarity in the coding regions and significant divergence in the untranslated regions. RT-PCR and Southern blotting using 3′-untranslated region (3′-UTR) as specific probe revealed that pea isoactin genes were expressed in roots, stems, leaves, tendrils, pollen and juvenile siliques, but displayed different patterns of transcript accumulation. Two-fold serial dilution electrophoresis showed PEAcⅠ mRNA preferentially accumulated in rapidly developing tissues: it peaked in seven days' stem; remained at a rather high level in leaves within a month but decreased significantly later; varied a little in tendrils and reached a median and a very low level respectively in juvenile siliques and in pollen. PEAcⅡ displayed somewhat similar expression pattern to PEAcⅠ. The observed differences in sequences and transcript accumulation patterns suggest that the individual pea actin genes may differ in their transcriptional regulation and cellular function. Phylogenetic tree of actins showed that pea actin isoforms are as diverged from each other as they are from other plant actins, and pea actins might have originated from a common ancestor before the divergence of the dicot and monocot plants.
