春化低温处理可以使拟南芥等十字花科植物提前开花,该过程中涉及到一个重要的植物同源结构域指(PHD-finger)蛋白VERNALIZATION INSENSITIVE3(VIN3)。PHD-finger结构域是真核生物中一种进化保守的锌指结构域,通常参与蛋白质之间的相互作用,特别是对核小体组蛋白进行甲基化、乙酰化、磷酸化等修饰。在春化处理过程中,VIN3及其同源基因编码的蛋白都具有PHD—finger结构域,该结构域通过对开花抑制基因FLOWERING LOCUSC染色质组蛋白进行H3K9、H3K27甲基化、H3K9和H3K14去乙酰化等修饰,调节FLC染色质结构状态,使其从松弛状态转变为高度凝缩状态而关闭其功能,从而影响FLC转录活性进而促进开花。以下综述了拟南芥等十字花科植物春化作用途径中PHD—finger蛋白的功能,并且概述了春化作用机制。
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 vemaliazation 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.