植物学人|20171117-朱健康等人揭示植物SnRKs的上游激酶涉及盐胁迫耐受性（推荐，另外Nature解析了小麦相关基因组）

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iNature：在植物学主流专刊中，主要有Plant Cell，Molecular Plant，Plant Journal，PLANT PHYSIOLOGY，NEW PHYTOLOGIST，Plant Biotech J，Plant Cell &Environ，Nature Plants等8种期刊，另外，加一个综合性的杂志，选定标准主要是IF>9（PNAS以上级别）以上。现在经过前期的测试，iNature决定每天遴选8大植物学主刊各1篇再加上综合性的杂志（IF>9，PNAS以上级别）一篇文章，共9篇文章，推送给大家，使大家能及时的了解植物学领域的动态：

Nature：美国加利福尼亚大学戴维斯分校Dvořák等人揭示小麦基因组测序又获新突破；

Plant Cell:清华大学钟上威等人揭示EIN3和PIF3形成一个抑制Buried的幼苗叶绿体发育的相互依赖的模块；

Nature Plants:美国特拉华大学Meyers等人揭示富含GC的编码序列减少了转座子样小RNA介导的转基因沉默；

Molecular Plant:英国剑桥大学Paszkowski等人揭示拟南芥中活性LTR逆转录转座子的序列独立性鉴定；

Plant Journal:中国科学院逆境中心朱健康等人揭示植物SnRKs的上游激酶涉及盐胁迫耐受性；

PLANT PHYSIOLOGY:西北农林科技大学郁飞等人揭示细胞翻译调节过程叶片颜色；

NEW PHYTOLOGIST:福建农林大学林辰涛等人发表光敏色素 - 隐花色素协同作用机制的新见解的综述；

Plant Biotech J:西班牙巴伦西亚理工大学Cañizares等人揭示西葫芦基因组的从头装配揭示了与南瓜属起源相关的全基因组重复序列；

Plant Cell &Environ:比利时根特大学Nelissen等人揭示玉米B104杂交种的增长率而不是生育期推动了杂种优势的增长。

1Nature Communications：美国加利福尼亚大学戴维斯分校Dvořák等人揭示小麦基因组测序又获新突破

Abstract

Aegilops tauschii is the diploid progenitor of the D genome of hexaploid wheat(Triticum aestivum, genomes AABBDD) and an important genetic resource for wheat. The large size and highly repetitive nature of the Ae. tauschii genome has until now precluded the development of a reference-quality genome sequence. Here we use an array of advanced technologies, including ordered-clone genome sequencing, whole-genome shotgun sequencing, and BioNano optical genome mapping, to generate a reference-quality genome sequence for Ae. tauschii ssp. strangulata accession AL8/78, which is closely related to the wheat D genome. We show that compared to other sequenced plant genomes, including a much larger conifer genome, the Ae. tauschii genome contains unprecedented amounts of very similar repeated sequences. Our genome comparisons reveal that the Ae. tauschii genome has a greater number of dispersed duplicated genes than other sequenced genomes and its chromosomes have been structurally evolving an order of magnitude faster than those of other grass genomes. The decay of colinearity with other grass genomes correlates with recombination rates along chromosomes. We propose that the vast amounts of very similar repeated sequences cause frequent errors in recombination and lead to gene duplications and structural chromosome changes that drive fast genome evolution.

原文链接：

https://www.nature.com/articles/nature24486

2Plant Cell：清华大学钟上威等人揭示EIN3和PIF3形成一个抑制Buried的幼苗叶绿体发育的相互依赖的模块

Abstract

In buried seedlings, chloroplasts are arrested at the etioplast stage, but they rapidly mature upon emergence of the seedling. Etioplast-chloroplast differentiation is halted through the integration of soil-induced signals, including pressure and the absence of light, although the details on how this information converges to regulate cellular decisions remain unclear. Here, we identify an interdependent transcription module that integrates the mechanical pressure and darkness signals to control chloroplast development in Arabidopsis thaliana. Mutations of ETHYLENE-INSENSITIVE3 (EIN3), the primary transcription factor in the ethylene signaling pathway that is activated in response to mechanical pressure, cause early development of etioplasts in the dark and severe photobleaching upon light exposure. Genetic studies demonstrate that repression of etioplast differentiation by EIN3 requires PHYTOCHROME INTERACTING FACTOR 3 (PIF3), a darkness-stabilized bHLH transcription factor. EIN3 and PIF3 directly interact and form an interdependent module to repress the expression of most LIGHT HARVESTING COMPLEX (LHC) genes; overexpressing even one LHC could cause premature development of etioplasts. The EIN3-PIF3 transcription module synergistically halts chloroplast development by interdependently co-occupying the promoters of LHC genes. Thus, our results define a transcriptional regulatory module and provide mechanistic insight on the concerted regulation of chloroplast development by multiple soil-induced signals.

原文链接：

http://www.plantcell.org/content/early/2017/11/07/tpc.17.00508

3Nature Plants：美国特拉华大学Meyers等人揭示富含GC的编码序列减少了转座子样小RNA介导的转基因沉默

Abstract

The molecular basis of transgene susceptibility to silencing is poorly characterized in plants; thus, we evaluated several transgene design parameters as means to reduce heritable transgene silencing. Analyses of Arabidopsis plants with transgenes encoding a microalgal polyunsaturated fatty acid (PUFA) synthase revealed that small RNA (sRNA)-mediated silencing, combined with the use of repetitive regulatory elements, led to aggressive transposon-like silencing of canola-biased PUFA synthase transgenes. Diversifying regulatory sequences and using native microalgal coding sequences (CDSs) with higher GC content improved transgene expression and resulted in a remarkable trans-generational stability via reduced accumulation of sRNAs and DNA methylation. Further experiments in maize with transgenes individually expressing three crystal (Cry) proteins from Bacillus thuringiensis (Bt) tested the impact of CDS recoding using different codon bias tables. Transgenes with higher GC content exhibited increased transcript and protein accumulation. These results demonstrate that the sequence composition of transgene CDSs can directly impact silencing, providing design strategies for increasing transgene expression levels and reducing risks of heritable loss of transgene expression.

原文链接：

https://www.nature.com/articles/s41477-017-0040-6

4Molecular Plant：英国剑桥大学Paszkowski等人揭示拟南芥中活性LTR逆转录转座子的序列独立性鉴定

Abstract

Detection of retrotransposons capable of contemporary transposition is hampered by the replicative nature of their movement and is usually limited to fortuitous observations of new integration events causing visible phenotypes. To circumvent this shortcoming, we developed a screening strategy for novel active retrotransposons containing long terminal repeats (LTR-TEs). Our approach is based on specific recovery of an LTR region that is part of the linear extrachromosomal DNA (ecDNA) synthetized in the reverse transcription step of the LTR-TE replication/transposition cycle. The method is inexpensive and straightforward and does not require prior knowledge of the retroelement sequence. Here we demonstrate the high sensitivity and specificity of this approach using Arabidopsis mutants with known retrotransposon activities. Using this method, we then identified a novel and mobile retroelement in the Landsberg erecta Arabidopsis ecotype that is absent in the annotated reference genome of Col-0. The cost-effective procedure presented here can be used to identify transposition-competent LTR-retrotransposons in a broad variety of biological specimens, independent of their sequence annotation.

原文链接：

http://www.cell.com/molecular-plant/fulltext/S1674-2052(17)30311-8

5Plant Journal：中国科学院逆境中心朱健康等人揭示植物SnRKs的上游激酶涉及盐胁迫耐受性

Abstract

Sucrose-Non-Fermenting1-related protein kinases (SnRKs) are important for plant growth and stress responses. This family has three clades: SnRK1, SnRK2, and SnRK3. Although plant SnRKs are thought to be activated by upstream kinases, the overall mechanism remains obscure. Geminivirus Rep-Interacting Kinase (GRIK)1 and GRIK2 phosphorylate SnRK1s, which are involved in sugar/energy sensing, and the grik1-1 grik2-1double mutant shows growth retardation under regular growth conditions. In this study, we established another Arabidopsis mutant line harbouring a different allele of gene GRIK1 (grik1-2 grik2-1) that grows similarly to the wild type, enabling us to evaluate the function of GRIKs under stress conditions. In the grik1-2 grik2-1 double mutant, phosphorylation of SnRK1.1 was reduced, but not eliminated, suggesting that the grik1-2 mutation is a weak allele. In addition to high sensitivity to glucose, the grik1-2 grik2-1 mutant was sensitive to high salt, indicating that GRIKs are also involved in salinity signalling pathways. Salt Overly Sensitive (SOS)2, a member of the SnRK3 subfamily, is a critical mediator of the response to salinity. GRIK1 phosphorylated SOS2 in vitro, resulting in elevated kinase activity of SOS2. The salt tolerance of sos2 was restored to normal levels by wild-type SOS2, but not by a mutated form of SOS2 lacking the T168 residue phosphorylated by GRIK1. Activation of SOS2 by GRIK1 was also demonstrated in a reconstituted system in yeast. Our results indicate that GRIKs phosphorylate and activate SnRK1 and other members of the SnRK3 family and that they play important roles in multiple signalling pathways in vivo.

原文链接：

http://onlinelibrary.wiley.com/doi/10.1111/tpj.13761/full

6PLANT PHYSIOLOGY：西北农林科技大学郁飞等人揭示细胞翻译调节过程叶片颜色

Abstract

The development of functional chloroplasts relies on the fine coordination of expressions of both nuclear and chloroplast genomes. We have been using the Arabidopsis yellow variegated (var2) leaf variegation mutant as a tool to dissect the regulation of chloroplast development. In this work, we screened for var2 genetic enhancer modifiers termed enhancer of variegation (evr) mutants and report the characterization of the first EVR locus, EVR1. We showed that EVR1 encodes the cytosolic 80S ribosome 40S small subunit protein RPS21B and the loss of EVR1 causes the enhancement of var2 leaf variegation. We further demonstrated that combined S21 activities from EVR1 and its close homolog, EVR1L1, are essential for Arabidopsis, and they act redundantly in regulating leaf development and var2 leaf variegation. Moreover, using additional cytosolic ribosomal protein mutants, we showed that although mutations in cytosolic ribosomal proteins all enhance var2 leaf variegation to varying degrees, 40S subunit appears to have a more profound role over 60S subunit in regulating VAR2-mediated chloroplast development. Comprehensive genetic analyses with var2 suppressors that are defective in chloroplast translation established that the enhancement of var2 leaf variegation by cytosolic ribosomal protein mutants is dependent on chloroplast translation. Based on our data, we propose a model that incorporates the suppression and enhancement of var2 leaf variegation, and hypothesize that VAR2/AtFtsH2 may be intimately involved in the balancing of cytosolic and chloroplast translation programs during chloroplast biogenesis.

原文链接：

http://www.plantphysiol.org/content/early/2017/11/15/pp.17.00673

7NEW PHYTOLOGIST：福建农林大学林辰涛等人发表光敏色素 - 隐花色素协同作用机制的新见解的综述

Abstract

Plants perceive and respond to light signals by multiple sensory photoreceptors, including phytochromes and cryptochromes, which absorb different wavelengths of light to regulate genome expression and plant development. Photophysiological analyses have long revealed the coordinated actions of different photoreceptors, a phenomenon referred to as the photoreceptor coaction. The mechanistic explanations of photoreceptor coactions are not fully understood. The function of direct protein–protein interaction of phytochromes and cryptochromes and common signaling molecules of these photoreceptors, such as SPA1/COP1 E3 ubiquitin ligase complex and bHLH transcription factors PIFs, would partially explain phytochrome–cryptochrome coactions. In addition, newly discovered proteins that block cryptochrome photodimerization or catalyze cryptochrome phosphorylation may also participate in the phytochrome and cryptochrome coaction. This Tansley insight, which is not intended to make a comprehensive review of the studies of photoreceptor coactions, attempts to highlight those recent findings and their possible roles in the photoreceptor coaction.

原文链接：

http://onlinelibrary.wiley.com/doi/10.1111/nph.14886/full

8Plant Biotech J：西班牙巴伦西亚理工大学Cañizares等人揭示西葫芦基因组的从头装配揭示了与南瓜属起源相关的全基因组重复序列

Abstract

The Cucurbita genus (squashes, pumpkins and gourds) includes important domesticated species such as C. pepo, C. maxima and C. moschata. In this study, we present a high-quality draft of the zucchini (C. pepo) genome. The assembly has a size of 263 Mb, a scaffold N50 of 1.8 Mb, and 34,240 gene models. It includes 92% of the conserved BUSCO core gene set, and it is estimated to cover 93.0% of the genome. The genome is organized in 20 pseudomolecules that represent 81.4% of the assembly, and it is integrated with a genetic map of 7,718 SNPs. Despite the small genome size, three independent lines of evidence support that the C. pepo genome is the result of a Whole Genome Duplication: the topology of the gene family phylogenies, the karyotype organization, and the distribution of 4DTv distances. Additionally, 40 transcriptomes of 12 species of the genus were assembled and analyzed together with all the other published genomes of the Cucurbitaceae family. The duplication was detected in all the Cucurbita species analyzed, including C. maximaand C. moschata, but not in the more distant cucurbits belonging to the Cucumis and Citrullus genera, and it is likely to have occurred 30 ± 4 Mya in the ancestral species that gave rise to the genus.

原文链接：

http://onlinelibrary.wiley.com/doi/10.1111/pbi.12860/full

9Plant Cell &Environ：比利时根特大学Nelissen等人揭示玉米B104杂交种的增长率而不是生育期推动了杂种优势的增长

Abstract

Research in maize is often performed using inbred lines which can be readily transformed, such as B104. However, B104 flowers late so that the kernels not always mature before the end of the growing season, hampering routine seed yield evaluations of biotech traits introduced in B104 at many geographical locations. Therefore, we generated five hybrids by crossing B104 with the early-flowering inbred lines CML91, F7, H99, Mo17 and W153R and showed in three consecutive years that the hybrid lines proved to be suitable to evaluate seed yield under field conditions in a temperate climate. By assessing the two main processes driving maize leaf growth, being rate of growth (leaf elongation rate or LER) and the duration of growth (leaf elongation duration or LED) in this panel of hybrids, we showed that leaf growth heterosis was mainly the result of increased LER and not or to a lesser extent of LED. Ectopic expression of the transgenes GA20-oxidase(GA20-OX) and PLASTOCHRON1 (PLA1), known to stimulate the LER and LED, respectively, in the hybrids showed that leaf length heterosis can be stimulated by increased LER, but not by LED, indicating that LER rather than LED is the target for enhancing leaf growth heterosis.

原文链接：

http://onlinelibrary.wiley.com/doi/10.1111/pce.13099/full

原文下载

https://pan.baidu.com/s/1dF4d9CX（植物学人，9篇文章，可直接下载，仅用于教育，不得商用）

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