Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/36042
標題: 植物中調節分生組織活性之NAC-like基因及與開花、老化相關之GIGANTEA(GI)同源基因之功能分析及應用
Functional analysis and the application of NAC-like genes and GIGANTEA(GI) orthologues in regulating meristematic activity, flowering and senescence in plants
作者: 施靜芳
Shih, Ching-Fang
關鍵字: meristem;分生組織;NAC-like gene;GIGANTEA;senescence;老化
出版社: 生物科技學研究所
摘要: 
NAC-like基因是在其蛋白質N端帶有約150個氨基酸之NAC domain的基因群,其被認為參與調控多種植物的發育過程。本研究在分析探討三個阿拉伯芥之NAC-like基因,AtNACL1,AtNACL2及NAC2。在mRNA的表現方面,此三個基因皆可在花序分生組織、花苞及葉片中偵測到基因的表現,但在根部,AtNACL1及NAC2基因有表現,而AtNACL2則沒有表現。另外在分析AtNACL1與AtNACL2 T-DNA插入(insertional)或反股(antisense)突變株中發現,其葉、芽莖、花及根之生長皆發生嚴重變異,植株出現異常葉,多花序之叢生狀芽莖及叢生狀之根的性狀。進一步分析此兩基因突變之植株,發現造成這些突變之性狀與一些已知參與分生組織發育相關基因,如:SERRATE、FASCIATA、WUS、DBP及與細胞分裂素(cytokinin)調節相關基因KNAT1 , STM等之異常表現有關。本研究結果不只顯示AtNACL1及AtNACL2具有調控頂芽及根分生組織的活性,並且提供了新的訊息以幫助了解NAC-like基因在植物發育中扮演的功能。為了進一步探討與此兩基因產物相互作用之蛋白質,本研究亦同時進行yeast-two hybrid之實驗,以利後續分析之工作。前人研究指出,將阿拉伯芥中的GIGANTEA(GI)基因突變後會出現開花及老化延遲之現象。本研究由青花菜(Brassica oleracea)中選殖出一個GI 之同源基因,BoGI。BoGI mRNA在發育過程中,可在葉片、芽、根及花苞處偵測到表現。進一步分析發現,BoGI之表現受生理時鐘所調節,在光照後8-12小時表現最高,而在清晨時最低。為了藉由BoGI/GI基因來研究其參與之老化-開花機制的調節,及其在農業上的應用如控制青花菜的開花時間及花苞老化的現象,本研究構築了一些構築體包括以35S promoter及一個與花器專一性表現的AP1 promoter來大量表現GI/BoGI 之antisense cDNA,並將這些構築體轉殖至阿拉伯芥及青花菜中,並已成功得到轉殖植株。進一步分析這些轉殖株綠色期延長情況之結果應可幫助增加青花菜市場上的價值與農民實質上的利益。

NAC-like genes that contained a conserved 150 amino acid NAC domain at their N-terminus of proteins have been considered to be involved in the regulation of many processes of plant development. AtNACL1, AtNACL2 and NAC2 with conserved NAC domain were identified in Arabidopsis. AtNACL1, AtNACL2 and NAC2 mRNA were detected in the inflorescence meristem, floral buds, and leaves. AtNACL1 and NAC2 mRNA is also expressed in roots where AtNACL2 expression is absent. Shoot, leaf, flower and root formation was severely altered in T-DNA insertional or antisense mutants of AtNACL1 and AtNACL2 by producing serrated leaves, generating a bushy phenotype with numerous inflorescences and branches of roots. Further analysis indicated that the mutant phenotypes were correlated with the alteration of the expression for genes involved in meristematic development such as FASCIATA, SERRATE, WUS, DBP and cytokinin regulating pathway such as KNAT1 , STM in mutants of AtNACL1 and AtNACL2. These results provided new insight of the function for NAC-like genes in plants. To investigate the interacting proteins for AtNACL1, 2, yeast two-hybrid assay is in progress. Mutation in GIGANTEA (GI) caused delay of flowering and senescence in Arabidopsis. BoGI, a GI orthologue was isolated and characterized from Brassica oleracea. BoGI mRNA is expressed throughout development and can be detected in leaves, shoot, root and flowers. Further analysis indicated that the expression of BoGI is modulated by the circadian clock. To investigate the senescence-flowering associated mechanism regulated by BoGI/GI genes and the agricultural application of BoGI/GI in controlling flowering time and floret yellowing for B. oleracea, constructs contained antisense cDNA of GI/BoGI driven by 35S or a flower specific AP1 promoter were transformed into Arabidopsis and B. oleracea and the transgenic plants were generated. Further confirm of the elongation of the green period in the transgenic plants should increase the market value and directly benefit to the farmers.
URI: http://hdl.handle.net/11455/36042
Appears in Collections:生物科技學研究所

Show full item record
 

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.