2Plant cell| 通過(guò)HY5轉(zhuǎn)錄因子調(diào)控開(kāi)放閱讀中的遠(yuǎn)紅光檢測(cè)調(diào)節(jié)側(cè)根發(fā)育

Far-Red Light Detection in the Shoot Regulates Lateral Root Development through the HY5 Transcription Factor

來(lái)自：荷蘭烏特勒支大學(xué)生物系

    Abstract

Plants in dense vegetation(植被) compete for resources and detect competitors through reflection of far-red (FR) light from surrounding plants. This reflection causes a reduced red (R):FR ratio, which is sensed through phytochromes(光敏色素). Low R:FR induces shade avoidance(逃避) responses of the shoot and also changes the root system architecture, although this has received little attention so far. Here, we investigate the molecular mechanisms through which light detection in the shoot regulates root development in Arabidopsis thaliana. We do so using a combination of microscopy(顯微鏡檢查), gene expression, and mutant(突變體) study approaches in a setup that allows root imaging without exposing the roots to light treatment. We show that low R:FR perception in the shoot decreases the lateral root (LR) density by inhibiting(抑制) LR emergence(出現(xiàn)). This decrease in LR emergence upon shoot FR enrichment(豐富) is regulated by phytochrome-dependent accumulation of the transcription factor ELONGATED HYPOCOTYL5 (HY5) in the LR primordia(原基). HY5 regulates LR emergence by decreasing the plasma membrane abundance of PIN-FORMED3 and LIKE-AUX1 3 auxin(植物生長(zhǎng)素) transporters. Accordingly, FR enrichment reduces the auxin signal in the overlaying cortex(皮質(zhì)) cells, and this reduces LR outgrowth. This shoot-to-root communication can help plants coordinate resource partitioning under competition for light in high density fields.

Supplemental FR Experienced by the Shoot Leads to Reduced Lateral and Primary Root Growth.

    Enhanced Availability of HY5 under FR Enrichment Inhibits Lateral Root Emergence.

密集植物中的植物競(jìng)爭(zhēng)資源，通過(guò)反射來(lái)自周?chē)参锏倪h(yuǎn)紅光（FR）來(lái)檢測(cè)競(jìng)爭(zhēng)者。這種反射導(dǎo)致通過(guò)光敏色素感測(cè)到的紅（R）：FR比率降低。低R：FR誘導(dǎo)枝條的遮蔭避免響應(yīng)，并且也改變了根系統(tǒng)結(jié)構(gòu)，盡管迄今為止這已經(jīng)不太受關(guān)注。在這里，我們調(diào)查的分子機(jī)制，通過(guò)其中光檢測(cè)調(diào)節(jié)擬南芥根發(fā)育。我們這樣做是在顯微鏡，基因表達(dá)和突變研究方法的結(jié)合下進(jìn)行的，這種方法允許根成像，而不需要將根暴露于光照處理。我們表明，在射擊低R：FR感知通過(guò)抑制LR的出現(xiàn)減少側(cè)根（LR）密度。這種LR出現(xiàn)在枝條FR富集時(shí)的減少受到LR原基中轉(zhuǎn)錄因子ELONGATED HYPOCOTYL5（HY5）的光敏色素依賴性積累的調(diào)節(jié)。 HY5通過(guò)降低PIN-FORMED3和LIKE-AUX1 3生長(zhǎng)素轉(zhuǎn)運(yùn)蛋白的質(zhì)膜豐度來(lái)調(diào)節(jié)LR的出現(xiàn)。因此，富集FR減少了重疊的皮層細(xì)胞中的生長(zhǎng)素信號(hào)，并且這降低了LR長(zhǎng)出。這種基于對(duì)話的交流可以幫助植物在高密度領(lǐng)域的光照競(jìng)爭(zhēng)下協(xié)調(diào)資源分配。

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Structure of the Arabidopsis JMJ14-H3K4me3 Complex Provides Insight into the Substrate Specificity of KDM5 Subfamily Histone Demethylases

Zhenlin Yang, Qi Qiu, Wei Chen, Bei Jia, Xiaomei Chen, Hongmiao Hu, Kaixuan He, Xian Deng, Sisi Li, W. Andy Tao, Xiaofeng Cao, Jiamu Du

來(lái)源：

1Jiamu Du

中科院上海植物逆境生物學(xué)研究中心杜嘉木研究組招聘博士后

National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, China

2 Xiaofeng Cao

University of Chinese Academy of Sciences, Beijing 100049, ChinaState Key Laboratory of Plant Genomics and National Center for Plant Gene Research, CAS Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China

在染色質(zhì)中，組蛋白甲基化影響動(dòng)物和植物中多個(gè)過(guò)程的表觀遺傳調(diào)節(jié)，并受組蛋白甲基轉(zhuǎn)移酶和組蛋白去甲基化酶的活性調(diào)節(jié)。含有jumonji結(jié)構(gòu)域的組蛋白去甲基化酶具有不同的功能，可分為幾個(gè)亞家族。在人類中，含有jumonji結(jié)構(gòu)域的賴氨酸（K）特異性脫甲基酶5 / Jumonji和ARID結(jié)構(gòu)域蛋白（KDM5 / JARID）亞家族脫甲基酶對(duì)組蛋白3賴氨酸4三甲基化（H3K4me3）是特異性的，并且是癌癥治療的重要藥物靶標(biāo)。在擬南芥中，KDM5 / JARID亞家族H3K4me3脫甲基化酶JUMONJI14（JMJ14）在開(kāi)花，基因沉默和DNA甲基化中起重要作用。在這里，我們報(bào)告了無(wú)基質(zhì)和結(jié)合形式的JMJ14催化結(jié)構(gòu)域的晶體結(jié)構(gòu)。結(jié)構(gòu)顯示jumonji和C5HC2結(jié)構(gòu)域有助于H3R2和H3Q5的特異性識(shí)別以促進(jìn)H3K4me3底物特異性。關(guān)鍵的酸性殘基在植物和動(dòng)物中是保守的，相應(yīng)的突變會(huì)損害JMJ14和人KDM5B的酶活性，表明KDM5亞家族脫甲基酶與植物和動(dòng)物共有的共同底物識(shí)別機(jī)制，并進(jìn)一步說(shuō)明設(shè)計(jì)人類靶向抑制劑的努力KDM5。

    Abstract

In chromatin(核染色質(zhì)), histone(組蛋白) methylation(甲基化) affects the epigenetic(后生的)regulation of multiple processes in animals and plants and is modulated(已調(diào)的) by the activities of histone methyltransferases(甲基轉(zhuǎn)移酶) and histone demethylases. The jumonji domain-containing histone demethylases have diverse functions and can be classified into several subfamilies(亞科). In humans, the jumonji domain-containing Lysine(賴氨酸) (K)-Specific Demethylase 5/Jumonji and ARID Domain Protein (KDM5/JARID) subfamily demethylases are specific for histone 3 lysine 4 trimethylation (H3K4me3) and are important drug targets for cancer treatment. In Arabidopsis thaliana, the KDM5/JARID subfamily H3K4me3 demethylase JUMONJI14 (JMJ14) plays important roles in flowering, gene silencing, and DNA methylation. Here, we report the crystal structures of the JMJ14 catalytic domain in both substrate-free and bound forms. The structures reveal that the jumonji and C5HC2 domains contribute to the specific recognition of the H3R2 and H3Q5 to facilitate H3K4me3 substrate specificity(特異性). The critical acidic(酸的) residues are conserved(保存) in plants and animals with the corresponding mutations impairing(損害) the enzyme activity of both JMJ14 and human KDM5B, indicating a common substrate recognition mechanism for KDM5 subfamily demethylases shared by plants and animals and further informing efforts to design targeted inhibitors of human KDM5