光是影響植物發(fā)育的一個最重因素,，但目前人們還不了解光敏染料如何導(dǎo)致基因型因受外界影響而發(fā)生變化,。光在植物發(fā)育過程中的一個首要作用是將紅外/遠紅外光敏色素由細胞質(zhì)轉(zhuǎn)移至核質(zhì)體中。目前人們還不了解核質(zhì)體的功能,，所以美國杜克大學(xué)的Meng Chen及其同事對這一課題進行了研究,。他們發(fā)現(xiàn)具有不同色敏核質(zhì)體的擬南芥突變體hemera的細胞核具備某個特殊的功能。
以前曾有報告稱hemera是涉及轉(zhuǎn)錄的質(zhì)體復(fù)合體的一部分,，科學(xué)家此次發(fā)現(xiàn)hemera細胞核的信號傳導(dǎo)具有特別之處,。此外，他們的研究還表明光敏色素會在核體中發(fā)生水解,。（生物谷Bioon.com）
生物谷推薦英文摘要：
Cell doi：10.1016/j.cell.2010.05.007
Arabidopsis HEMERA/pTAC12 Initiates Photomorphogenesis by Phytochromes
Meng Chen, Rafaelo M. Galv?o, Meina Li, Brian Burger, Jane Bugea, Jack Bolado, Joanne Chory
Light plays a profound role in plant development, yet how photoreceptor excitation directs phenotypic plasticity remains elusive. One of the earliest effects of light is the regulated translocation of the red/far-red photoreceptors, phytochromes, from the cytoplasm to subnuclear foci called phytochrome nuclear bodies. The function of these nuclear bodies is unknown. We report the identification of hemera, a seedling lethal mutant of Arabidopsis with altered phytochrome nuclear body patterns. hemera mutants are impaired in all phytochrome responses examined, including proteolysis of phytochrome A and phytochrome-interacting transcription factors. HEMERA was identified previously as pTAC12, a component of a plastid complex associated with transcription. Here, we show that HEMERA has a function in the nucleus, where it acts specifically in phytochrome signaling, is predicted to be structurally similar to the multiubiquitin-binding protein, RAD23, and can partially rescue yeast rad23mutants. Together, these results implicate phytochrome nuclear bodies as sites of proteolysis.
