阿拉伯芥中FIN219 和PHYA 交互作用的功能性研究

Functional studies of FIN219 and PHYA interaction in Arabidopsis thaliana

趙俐雅(Li-Ya Chao)

指導教授 ： 謝旭亮

國立臺灣大學/生命科學院/植物科學研究所/碩士(2008年)

https://doi.org/10.6342/NTU.2008.03011

摘要

光敏素A (phytochrome A, phyA)為阿拉伯芥中遠紅光的接受體，主要接收波長700∼750 nm；FIN219 (Far-red light insensitive 219)是屬於GH3-like 基因家族中的一員，會被生長素(auxin)大量誘導表現；FIN219也是遠紅光下游的一個光訊息傳遞者，也參與藍光的訊息傳遞。當大量表現FIN219 使阿拉伯芥變得對遠紅光更敏感(hypersensitive)；FIN219缺失則變得對遠紅光不敏感(hyposensitive)。前人研究以LexA 酵母菌雙雜合系統也顯示FIN219 與phyA 有交互作用，本論文即是探討FIN219與光敏素A 之間的交互作用和調控關係。由共免疫沉澱法發現在黑暗中與遠紅光中，在植物體內FIN219 均能與phyA 有交互作用；上位性基因分析指出FIN219 作用於phyA 的下游，並且FIN219 蛋白質的表現僅在遠紅光phyA 突變株中有明顯下降，並且依phyA 突變程度的高低，FIN219 蛋白質含量也隨之降升；FIN219啟動子接GUS (pFIN219::GUS)轉基因到phyA 突變株或野生型，發現pFIN219::GUS/phyA 中GUS 染色大幅降低至幾乎沒有，顯示FIN219 蛋白質含量的多寡或FIN219表現與否取決於植物在遠紅光下phyA存在量的高低或是否存在。觀察GFP-FIN219*PHYA-F-DsRed 雜交植株的螢光，發現GFP-FIN219 在黑暗及遠紅光照射後，可同時與PHYA 出現在細胞核；此外FIN219 無論是否存在，不影響PHYA 進入細胞核的能力。

關鍵字

光敏素

並列摘要

Light is one of the most important enviroment factors, and plants have evolved complex and sophisticated mechanisms to adjust their development to fit this factor. Phytochrome A (phyA) is one of the most extensively studied photoreceptors. phyA mainly absords far-red light (FR,wavelength 700~750nm) in Arabidopsis. FAR-RED INSENSITIVE 219 (FIN219) belongs
to a GH3-like gene family in Arabidopsis and can be rapidly induced by auxin. There are two coiled-coil domains in FIN219 located in the N- and C-terminal regions respectively. Previous results from yeast two-hybrid studies revealed that the N- and C-terminal domains of FIN219 can interact
with the full length of PHYA. Thus, this thesis will confirm the interaction between FIN219 and PHYA, and investigate their regulatory relationship. Co-immunoprecipitation studies indicate that FIN219 can interact with PHYA in the dark and far-red light. Epistatic analysis reveals that FIN219
functions downstream of the photoreceptor phyA. Western blot results showed that FIN219 protein accumulation is positively regulated by PHYA under darkness and far-red light. FIN219 promoter::GUS activity assay in phyA (pFIN219::GUS/phyA) or wild type (pFIN219::GUS/Col-0) under darkness, white light and far-red light revealed that GUS staining is almost
abolished in the phyA mutant compared to that in wild type. In addition subcellular localization studies reveal that GFP-FIN219 can colocalize with PHYA-DsRed under darkness and far-red light but FIN219 is not specifically required for light-regulated nuclear accumulation of phyA.

並列關鍵字

FIN219 ； PHYA

參考文獻

Barnes, S.A., Nishizawa, N.K., Quaggio, R.B., Whitelam, G.C., and Chua, N.H. (1996). Far-red light blocks greening of Arabidopsis seedlings via a phytochrome A-mediated change in plastid development. Plant Cell 8, 601-615.

Bolle, C., Koncz, C., and Chua, N.H. (2000). PAT1, a new member of the GRAS family, is involved in phytochrome A signal transduction. Genes Dev 14, 1269-1278.

Botto, J.F., Sanchez, R.A., Whitelam, G.C., and Casal, J.J. (1996). Phytochrome A Mediates the Promotion of Seed Germination by Very Low Fluences of Light and Canopy Shade Light in Arabidopsis. Plant Physiol 110, 439-444.

Casal, J.J., Davis, S.J., Kirchenbauer, D., Viczian, A., Yanovsky, M.J., Clough, R.C., Kircher, S., Jordan-Beebe, E.T., Schafer, E., Nagy, F., and Vierstra, R.D. (2002). The serine-rich N-terminal domain of oat phytochrome a helps regulate light responses and subnuclear localization of the photoreceptor. Plant Physiol 129, 1127-1137.

Chai, Y.G., Song, P.S., Cordonnier, M.M., and Pratt, L.H. (1987). A photoreversible circular dichroism spectral change in oat phytochrome is suppressed by a monoclonal antibody that binds near its N-terminus and by chromophore modification. Biochemistry 26, 4947-4952.