植物学人|20171026-上海生科院何跃辉揭示植物开花表观遗传新机制（推荐）

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 :中科院上海生科院逆境中心何跃辉等人揭示植物春化过程与胚胎发育紧密的联系在了一起；

Plant Cell:比利时根特大学Maere等人揭示被子植物谱系中相互残留的基因显示剂量平衡灵敏度的标记；

Nature Plants:加利福尼亚大学Song等人揭示YopJ家族识别底物乙酰化的分子机制；

Molecular Plant:以色列魏兹曼科学研究所Aharoni等人发表玫瑰花色素的生物合成，来源和应用的综述；

Plant Journal:浙江大学张舒群等人揭示在拟南芥中通过MPK6及其上游MKK4和MKK5产生胚胎发育控制；

PLANT PHYSIOLOGY:西北农林科技大学郭军揭示宿主诱导的MAPKK基因PsFUZ7沉默，赋予对小麦条锈病的稳定抗性；

NEW PHYTOLOGIST:英国伦敦帝国学院Belanger等人揭示涉及真菌 - 真菌相互作用的效应物，导致在营养系统生物防治剂 - 白粉病霉菌中罕见的高营养不良现象；

Plant Biotech J:美国肯塔基大学Chappell等人揭示田间生长烟草的三萜和甲基化三萜烯代谢的农艺和化学性能；

Plant Cell &Environ:巴拿马共和国史密森尼亚热带研究所Winter等人揭示四个低地热带树种光合作用，生化和气孔控制的原位温度关系。

1Nature：中科院上海生科院逆境中心何跃辉等人揭示何跃辉揭示植物开花表观遗传新机制

Abstract

Epigenetic modifications, including chromatin modifications and DNA methylation, have a central role in the regulation of gene expression in plants and animals. The transmission of epigenetic marks is crucial for certain genes to retain cell lineage-specific expression patterns and maintain cell fate. However, the marks that have accumulated at regulatory loci during growth and development or in response to environmental stimuli need to be deleted in gametes or embryos, particularly in organisms such as plants that do not set aside a germ line, to ensure the proper development of offspring. In Arabidopsis thaliana, prolonged exposure to cold temperatures (winter cold), in a process known as vernalization, triggers the mitotically stable epigenetic silencing of the potent floral repressor FLOWERING LOCUS C (FLC), and renders plants competent to flower in the spring; however, this silencing is reset during each generation. Here we show that the seed-specific transcription factor LEAFY COTYLEDON1 (LEC1) promotes the initial establishment of an active chromatin state at FLC and activates its expression de novo in the pro-embryo, thus reversing the silenced state inherited from gametes. This active chromatin state is passed on from the pro-embryo to post-embryonic life, and leads to transmission of the embryonic memory of FLC activation to post-embryonic stages. Our findings reveal a mechanism for the reprogramming of embryonic chromatin states in plants, and provide insights into the epigenetic memory of embryonic active gene expression in post-embryonic phases, through which an embryonic factor acts to ‘control’ post-embryonic development processes that are distinct from embryogenesis in plants.

原文链接：

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature24300.html

2Plant Cell：比利时根特大学Maere等人揭示被子植物谱系中相互残留的基因显示剂量平衡灵敏度的标记

Abstract

In several organisms, particular functional categories of genes, such as regulatory and complex-forming genes, are preferentially retained after whole-genome multiplications but rarely duplicate through small-scale duplication, a pattern referred to as reciprocal retention. This peculiar duplication behavior is hypothesized to stem from constraints on the dosage balance between the genes concerned and their interaction context. However, the evidence for a relationship between reciprocal retention and dosage balance sensitivity remains fragmentary. Here, we identified which gene families are most strongly reciprocally retained in the angiosperm lineage and studied their functional and evolutionary characteristics. Reciprocally retained gene families exhibit stronger sequence divergence constraints and lower rates of functional and expression divergence than other gene families, suggesting that dosage balance sensitivity is a general characteristic of reciprocally retained genes. Gene families functioning in regulatory and signaling processes were much more strongly represented at the top of the reciprocal retention ranking than those functioning in multiprotein complexes, suggesting that regulatory imbalances may lead to stronger fitness effects than classical stoichiometric protein complex imbalances. Finally, reciprocally retained duplicates are often subject to dosage balance constraints for prolonged evolutionary times, which may have repercussions for the ease with which genome multiplications can engender evolutionary innovation.

原文链接：

http://www.plantcell.org/content/early/2017/10/23/tpc.17.00313

3Nature Plants：加利福尼亚大学Song等人揭示YopJ家族识别底物乙酰化的分子机制

Abstract

The Yersinia outer protein J (YopJ) family of bacterial effectors depends on a novel acetyltransferase domain to acetylate signalling proteins from plant and animal hosts. However, the underlying mechanism is unclear. Here, we report the crystal structures of PopP2, a YopJ effector produced by the plant pathogen Ralstonia solanacearum, in complex with inositol hexaphosphate (InsP6), acetyl-coenzyme A (AcCoA) and/or substrate Resistance to Ralstonia solanacearum 1 (RRS1-R)WRKY. PopP2 recognizes the WRKYGQK motif of RRS1-RWRKY to position a targeted lysine in the active site for acetylation. Importantly, the PopP2–RRS1-RWRKY association is allosterically regulated by InsP6 binding, suggesting a previously unidentified role of the eukaryote-specific cofactor in substrate interaction. Furthermore, we provide evidence for the reaction intermediate of PopP2-mediated acetylation, an acetyl-cysteine covalent adduct, lending direct support to the ‘ping-pong’-like catalytic mechanism proposed for YopJ effectors. Our study provides critical mechanistic insights into the virulence activity of YopJ class of acetyltransferases.

原文链接：

https://www.nature.com/articles/nplants2017115

4Molecular Plant：以色列魏兹曼科学研究所Aharoni等人发表玫瑰花色素的生物合成，来源和应用的综述

Abstract

This review discusses betalain metabolism in light of recent advances in the field, with an up-to-date survey of characterized genes and enzymes that take part in betalain biosynthesis, catabolism and transcriptional regulation. Currently-used and potential new sources for betalains are discussed, together with a summary of possible applications of betalains in research and commercial use.

原文链接：

http://www.cell.com/molecular-plant/fulltext/S1674-2052(17)30307-6

5Plant Journal：浙江大学张舒群等人揭示在拟南芥中通过MPK6及其上游MKK4和MKK5产生胚胎发育控制

Abstract

In flowering plants, developing embryos reside in maternal sporophytes. It is known that maternal generation influences the development of next-generation embryos. However, little is known about the signaling components in the process. Previously, we demonstrated that Arabidopsis mitogen-activated protein kinase 6 (MPK6) and MPK3 play critical roles in plant reproduction. In addition, we noticed that a large fraction of seeds from mpk6 single mutant plants showed a wrinkled seed coat or a burst-out embryo phenotype. Here, we report that these seed phenotypes can be traced back to defective embryogenesis. The defective embryos have shorter suspensors and reduced growth along the longitudinal axis. Furthermore, the cotyledons fail to bend over to progress to the bent-cotyledon stage. As a result of the uneven circumferences along the axis, the seed coat wrinkles to give the raisin-like morphology after dehydration. In the more severe cases, the embryo can be pushed out from the micropylar end, resulting in the burst-out embryo seed phenotype. Genetic analyses demonstrated that the defective embryogenesis of mpk6 mutant is a maternal effect. Heterozygous or homozygous mpk6 embryos have defects only in mpk6 homozygous maternal plants, but not wild-type or heterozygous maternal plants. Loss of function of MKK4 and MKK5 also results in the same phenotypes, suggesting that MKK4/MKK5 might be upstream of MPK6 in this pathway. The maternal-mediated embryo defects are associated with changes in auxin activity maxima and PIN localization. In summary, this research demonstrates that Arabidopsis MKK4/MKK5-MPK6 cascade is an important player in the maternal control of embryogenesis.

原文链接：

http://onlinelibrary.wiley.com/doi/10.1111/tpj.13737/full

6PLANT PHYSIOLOGY：西北农林科技大学郭军揭示宿主诱导的MAPKK基因PsFUZ7沉默，赋予对小麦条锈病的稳定抗性

Abstract

RNA interference (RNAi) is a powerful genetic tool to accelerate research in plant biotechnology and to control biotic stresses by manipulating target gene expression. However, the potential of RNAi in wheat to efficiently and durably control the devastating stripe rust fungus Puccinia striiformis f. sp. tritici (Pst), remained largely under explored, so far. To address this issue, we generated transgenic wheat lines expressing double-stranded RNA targeting PsFUZ7 transcripts of Pst. We analyzed expression of PsFUZ7 and related genes, and resistance traits of the transgenic wheat lines. We show that PsFUZ7 is an important pathogenicity factor which regulates infection and development of Pst. A PsFUZ7 RNAi construct stably expressed in two independent transgenic wheat lines confers strong resistance to Pst. Pst hyphal development is strongly restricted, and necrosis of plant cells in resistance responses was significantly induced. We conclude that trafficking of RNA molecules from wheat plants to Pst may lead to a complex molecular dialogue between wheat and the rust pathogen. Moreover, we confirm the RNAi-based crop protection approaches can be used as a novel control strategy against rust pathogens in wheat.

45 33957 45 15289 0 0 1114 0 0:00:30 0:00:13 0:00:17 3599>

原文链接：

http://www.plantphysiol.org/content/early/2017/10/25/pp.17.01223

7NEW PHYTOLOGIST：英国伦敦帝国学院Belanger等人揭示涉及真菌 - 真菌相互作用的效应物，导致在营养系统生物防治剂 - 白粉病霉菌中罕见的高营养不良现象

Abstract

Powdery mildew causes important losses to a wide range of agricultural and horticultural plants. Despite being recognized as one disease, over 650 powdery mildew species are known to occur on nearly 10 000 host species . Powdery mildew fungi belong to the Erysiphales within the Ascomycota and are obligate biotrophic parasites. To establish infection, they depend on living cells where they form a specialized feeding structure, the haustorium, which invaginates the plasma membrane of the host epidermal cell. The interaction between the haustorium and the plant cell is tightly regulated so that the fungus can obtain resources from the plant without killing it . Diversion of nutrients from the host to powdery mildew fungus leads to the production of mycelium, conidiophores and conidia, thus maintaining the development and asexual reproduction of the fungus. For the plant, the infection results in reduced photosynthesis, slower development and lower productivity.

原文链接：

http://onlinelibrary.wiley.com/doi/10.1111/nph.14851/full

8Plant Biotech J：美国肯塔基大学Chappell等人揭示田间生长烟草的三萜和甲基化三萜烯代谢的农艺和化学性能

Abstract

Squalene is a linear intermediate to nearly all classes of triterpenes and sterols and is itself highly valued for its use in wide range of industrial applications. Another unique linear triterpene is botryococcene and its methylated derivatives generated by the alga Botryococcus braunii race B, which are progenitors to fossil fuel deposits. Production of these linear triterpenes was previously engineered into transgenic tobacco by introducing the key steps of triterpene metabolism into the particular subcellular compartments. In this study, the agronomic characteristics (height, biomass accumulation, leaf area), the photosynthetic capacity (photosynthesis rate, conductance, internal CO2 levels) and triterpene content of select lines grown under field conditions were evaluated for three consecutive growing seasons. We observed that transgenic lines targeting enzymes to the chloroplasts accumulated 50-150-time more squalene than the lines targeting the enzymes to the cytoplasm, without compromising growth or photosynthesis. We also found that the transgenic lines directing botryococcene metabolism to the chloroplast accumulated 10-33-fold greater levels than the lines where the same enzymes were targeted to in the cytoplasm. However, growth of these high botryococcene accumulators was highly compromised, yet their photosynthesis rates remained unaffected. In addition, in the transgenic lines targeting a triterpene methyltransferase (TMT) to the chloroplasts of high squalene accumulators, 55-65% of total squalene was methylated, whereas in the lines expressing a TMT in the cytoplasm only 6-13% of squalene was methylated. The growth of these methylated triterpene accumulating lines was more compromised than that of non-methylated squalene lines.

原文链接：

http://onlinelibrary.wiley.com/doi/10.1111/pbi.12855/full

9Plant Cell &Environ：巴拿马共和国史密森尼亚热带研究所Winter等人揭示四个低地热带树种光合作用，生化和气孔控制的原位温度关系

Abstract

Net photosynthetic carbon uptake of Panamanian lowland tropical forest species is typically optimal at 30–32°C. The processes responsible for the decrease in photosynthesis at higher temperatures are not fully understood for tropical trees. We determined temperature responses of maximum rates of RuBP-carboxylation (VCMax) and RuBP-regeneration (JMax), stomatal conductance (Gs) and respiration in the light (RLight) in situ for four lowland tropical tree species in Panama. Gs had the lowest temperature optimum (TOpt), similar to that of net photosynthesis, and photosynthesis became increasingly limited by stomatal conductance as temperature increased. JMax peaked at 34–37°C and VCMax ~2°C above that, except in the late-successional species Calophyllum longifolium, in which both peaked at ~33°C. RLight significantly increased with increasing temperature, but simulations with a photosynthesis model indicated that this had only a small effect on net photosynthesis. We found no evidence for Rubisco-activase limitation of photosynthesis. TOpt of VCMax and JMax fell within the observed in situ leaf temperature range, but our study nonetheless suggests that net photosynthesis of tropical trees is more strongly influenced by the indirect effects of high temperature—e.g., through elevated vapor pressure deficit and resulting decreases in stomatal conductance—than by direct temperature effects on photosynthetic biochemistry and respiration.

原文链接：

http://onlinelibrary.wiley.com/doi/10.1111/pce.13071/full

猜你喜欢

---

温馨提示：iNature是介绍一流的，最前沿的科研成果，提供专业的完整的同行解析；另外也会介绍全世界知名的实验室及业界大师；同时为公众提供一个了解生命科学及科研过程的平台。扫描或长按下方二维码可关注“Plant_ihuman”，了解科学领域最新研究进展。另外，iNature公众号也开通了“爱科学爱自然”头条号，欢迎大家关注。

投稿、合作、转载以及招聘信息发布等事宜请联系[e-mail] 或微信号“13701829856”。