植物同源結(jié)構(gòu)域指蛋白在擬南芥等十字花科植物春化作用途徑中的功能

胡功鈴，陳國平，胡宗利，顧峰，李勇

重慶大學(xué)生物工程學(xué)院，重慶 400030

植物同源結(jié)構(gòu)域指蛋白在擬南芥等十字花科植物春化作用途徑中的功能

胡功鈴，陳國平，胡宗利，顧峰，李勇

重慶大學(xué)生物工程學(xué)院，重慶 400030

春化低溫處理可以使擬南芥等十字花科植物提前開花，該過程中涉及到一個重要的植物同源結(jié)構(gòu)域指(PHD-finger)蛋白VERNALIZATION INSENSITIVE 3(VIN3)。PHD-finger結(jié)構(gòu)域是真核生物中一種進化保守的鋅指結(jié)構(gòu)域，通常參與蛋白質(zhì)之間的相互作用，特別是對核小體組蛋白進行甲基化、乙酰化、磷酸化等修飾。在春化處理過程中，VIN3及其同源基因編碼的蛋白都具有PHD-finger結(jié)構(gòu)域，該結(jié)構(gòu)域通過對開花抑制基因FLOWERING LOCUS C染色質(zhì)組蛋白進行H3K9、H3K27甲基化、H3K9和H3K14去乙酰化等修飾，調(diào)節(jié)FLC染色質(zhì)結(jié)構(gòu)狀態(tài)，使其從松弛狀態(tài)轉(zhuǎn)變?yōu)楦叨饶s狀態(tài)而關(guān)閉其功能，從而影響FLC轉(zhuǎn)錄活性進而促進開花。以下綜述了擬南芥等十字花科植物春化作用途徑中PHD-finger蛋白的功能，并且概述了春化作用機制。

植物同源結(jié)構(gòu)域指蛋白，VIN3，F(xiàn)LOWERING LOCUS C，春化作用，組蛋白修飾

Abstract:Vernalization makes Arabidopsis and other cruciferous plants flowering earlier.During this process, an important plant homeodomain-finger(PHD-finger)protein named VIN3 is involved.The PHD domain was a conserved zinc-finger domain in eukaryotic organism.It used to take part in the interaction between proteins, especially the modification on histone of nucleosome,such as methylation, acetylation and phosphorylation.In vernaliazation pathway, the proteins translated by VERNALIZATION INSENSITIVE 3(VIN3)and homologous genes could result in methylation on H3K9 and H3K27 and deacetylation on H3K9 and H3K14 on chromatin histone of FLOWERING LOCUS C, a gene that inhibited flowering.The structure state of FLC would be changed from relaxation into compression.Then the transcription activity of FLC could be restrained and it couldn’t inhibit flowering any more, so it would induce flowering earlier.This paper reviewed the function of PHD-finger proteins in vernalization pathway in Arabidopsis and other cruciferous plants, and overviewed the vernalization mechanism.

Keywords:plant homeodomain-finger proteins, VIN3, FLOWERING LOCUS C, vernalization, histone modification

目前，本實驗室在研究菜薹Brassica campestris L.ssp.chinensis var.utilissen.et Lee 早花原因的過程中發(fā)現(xiàn)春化處理(Vernalization)可以使菜薹提前開花10～20 d。根據(jù)擬南芥Arabidopsis及其蕓薹屬相關(guān)領(lǐng)域的研究報道，本研究將重點放在開花網(wǎng)絡(luò)核心基因FLOWERING LOCUS C(FLC)及其春化作用途徑上游的關(guān)鍵基因 VERNALIZATION INSENSITIVE 3(VIN3)上。研究發(fā)現(xiàn)，長時間(大于20 d)的低溫處理會誘導(dǎo)VIN3的表達，并使FLC表達量降低，此時菜薹的表型為早花。在模式植物擬南芥中很早前就有過這種現(xiàn)象的相關(guān)報道，并且對VIN3有較深入的研究。……