植物学人|20171022-德国马普学会Weigel等人通过使用Hi-C的方法揭示水稻中染色质的高级结构（推荐）
iNature：
Plant Cell:中国农业科学院王海洋揭示光和乙烯联合调控磷酸盐借应答过程，通过调节PHOSPHATE STARVATION RESPONSE1蛋白的转录过程；
Nature Plants:德国马普学会Weigel等人通过使用Hi-C的方法揭示水稻中染色质的高级结构；
Molecular Plant:中国农业大学李大伟等人揭示大麦条纹花叶病毒γb与乙醇酸氧化酶相互作用，抑制过氧化物酶体ROS产生，促进病毒感染；
Plant Journal:英国谢菲尔德大学Sadanandom等人揭示水稻SUMO蛋白酶OTS1靶向转录因子OsbZIP23，以促进水稻耐旱性;
PLANT PHYSIOLOGY:美国维克森林大学Muday等人揭示脱落酸诱导的活性氧由黄酮醇调节以控制气孔孔径；
NEW PHYTOLOGIST:日本理化研究所Noutoshi等人揭示水杨酸依赖性免疫作用有助于丝核菌（Rhizoctonia solani）产生抗性；
Plant Biotech J:西班牙马拉加大学Ávila等人揭示PpNAC1是海洋松树苯丙氨酸生物合成和利用的主要调节剂；
Plant Cell &Environ:中国农业科学院张永军等人揭示陆地棉中的萜烯合酶基因家族含有一种涉及对食草动物的直接防御反应的芳樟醇合酶GhTPS12。
1Plant Cell：中国农业科学院王海洋揭示光和乙烯联合调控磷酸盐借应答过程，通过调节PHOSPHATE STARVATION RESPONSE1蛋白的转录过程
Abstract
Plants have evolved an array of adaptive responses to low Pi availability, a process modulated by various external stimuli and endogenous growth regulatory signals. Little is known about how these signaling processes interact to produce an integrated response. Arabidopsis thaliana PHOSPHATE STARVATION RESPONSE1 (PHR1) encodes a conserved MYB-type transcription factor that is essential for programming Pi starvation-induced gene expression and downstream Pi starvation responses (PSRs). Here, we show that loss-of-function mutations in FHY3 and FAR1, encoding two positive regulators of phytochrome signaling, and in EIN3, encoding a master regulator of ethylene responses, cause attenuated PHR1 expression, whereas mutation in HY5, encoding another positive regulator of light signaling, causes increased PHR1 expression. FHY3, FAR1, HY5, and EIN3 directly bind to the PHR1 promoter through distinct cis-elements. FHY3, FAR1, and EIN3 activate, while HY5 represses, PHR1 expression. FHY3 directly interacts with EIN3, and HY5 suppresses the transcriptional activation activity of FHY3 and EIN3 on PHR1. Finally, both light and ethylene promote FHY3 protein accumulation, and ethylene blocks the light-promoted stabilization of HY5. Our results suggest that light and ethylene coordinately regulate PHR1 expression and PSRs through signaling convergence at the PHR1 promoter.
原文链接：
http://www.plantcell.org/content/plantcell/29/9/2269.full.pdf
2Nature Plants：德国马普学会Weigel等人通过使用Hi-C的方法揭示水稻中染色质的高级结构
Abstract
The non-random three-dimensional organization of genomes is critical for many cellular processes. Recently, analyses of genome-wide chromatin packing in the model dicot plant Arabidopsis thaliana have been reported. At a kilobase scale, the A. thaliana chromatin interaction network is highly correlated with a range of genomic and epigenomic features. Surprisingly, topologically associated domains (TADs), which appear to be a prevalent structural feature of genome packing in many animal species, are not prominent in the A. thaliana genome. Using a genome-wide chromatin conformation capture approach, Hi-C (ref. 7), we report high-resolution chromatin packing patterns of another model plant, rice. We unveil new structural features of chromatin organization at both chromosomal and local levels compared to A. thaliana, with thousands of distinct TADs that cover about a quarter of the rice genome. The rice TAD boundaries are associated with euchromatic epigenetic marks and active gene expression, and enriched with a sequence motif that can be recognized by plant-specific TCP proteins. In addition, we report chromosome decondensation in rice seedlings undergoing cold stress, despite local chromatin packing patterns remaining largely unchanged. The substantial variation found already in a comparison of two plant species suggests that chromatin organization in plants might be more diverse than in multicellular animals.
原文链接：
https://www.nature.com/articles/s41477-017-0005-9
3Molecular Plant：中国农业大学李大伟等人揭示大麦条纹花叶病毒γb与乙醇酸氧化酶相互作用，抑制过氧化物酶体ROS产生，促进病毒感染
Abstract
Plants are naturally infected by a wide range of pathogens including viruses, bacteria,and fungi, and have evolved many strategies to circumvent pathogenic stresses. Rapid generation of reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) or superoxide anions (O2-) are one of the earliest cellular responses against pathogen infections (Bolwell and Wojtaszek, 1997). After infection, an ROS burst is induced by NADPH oxidase (also known as respiratory burst oxidase homologs, RBOH), which catalyzes the conversion of O2 to superoxide (O2 -). An alternative ROS producing pathway is mediated by glycolate oxidase (GOX). GOX is a flavin mononucleotide (FMN) containing enzyme found in plant and mammalian peroxisomes that catalyzes oxidation of glycolate or its derivatives and generates glyoxylate and H2O2 during photorespiration. Either RBOH- or GOX-derived ROS have been shown to be
involved in plant defenses against bacterial pathogens.
原文链接：
http://www.cell.com/molecular-plant/fulltext/S1674-2052(17)30306-4
4Plant Journal：英国谢菲尔德大学Sadanandom等人揭示水稻SUMO蛋白酶OTS1靶向转录因子OsbZIP23，以促进水稻耐旱性
Abstract
Conjugation of SUMO (Small Ubiquitin-like Modifier) protein to cellular targets is emerging as a very influential protein modification system. Once covalently bound SUMO conjugation can change the stability or functionality of its cognate target proteins. SUMO protease can rapidly reverse SUMO conjugation making this modification system highly dynamic. A major factor in the variation of SUMO-target function is the balance between the conjugated/de-conjugated forms. The mechanistic role of these regulatory SUMO proteases in mediating stress responses has not been defined in any crops. In this study, we reveal the role of the SUMO protease, OsOTS1 in mediating tolerance to drought in rice. OsOTS1 depleted transgenic plants accumulate more ABA and exhibit more productive agronomic traits during drought whilst OsOTS1overexpressing lines are drought sensitive but ABA insensitive. Drought and ABA treatment stimulates the degradation of OsOTS1 protein indicating that SUMO conjugation is an important response to drought stress in rice achieved through down-regulation of OTS1/2 activity. We reveal that OsOTS1 SUMO protease directly targets the ABA and drought responsive transcription factor OsbZIP23 for de-SUMOylation affecting its stability. OsOTS-RNAi lines show increased abundance of OsbZIP23 and increased drought responsive gene expression while OsOTS1 overexpressing lines show reduced levels of OsbZIP23 leading to suppressed drought responsive gene expression. Our data reveals a mechanism where rice plants govern ABA dependant drought responsive gene expression by controlling the stability of OsbZIP23 by SUMO conjugation through manipulating specific SUMO protease levels.
原文链接：
http://onlinelibrary.wiley.com/doi/10.1111/tpj.13739/full
5PLANT PHYSIOLOGY：美国维克森林大学Muday等人揭示脱落酸诱导的活性氧由黄酮醇调节以控制气孔孔径
Abstract
Abscisic acid (ABA) increases reactive oxygen species (ROS) in guard cells to close Arabidopsis stomata. In Solanum lycopersicum we find that ABA increased ROS is followed by stomatal closure and both responses are blocked by inhibitors of ROS-producing respiratory burst oxidase enzymes. ABA-induced ROS sensor fluorescence accumulates in the nucleus, chloroplasts, and in endomembranes. Accumulation of flavonol antioxidants in guard cells, but not surrounding pavement cells, were visualized by confocal microscopy using a flavonol-specific fluorescent dye. Decreased flavonols in guard cells in the are mutant and elevated levels in the aw mutant were quantified by confocal microscopy and in leaf extracts by mass spectrometry. Consistent with flavonols acting as antioxidants, higher levels of ROS were detected in guard cells of the tomato are mutant and lower in aw both at homeostasis and after treatment with ABA. These results demonstrate the inverse relationship between flavonols and ROS. Guard cells of are show greater ABA-induced closure than WT, reduced light-dependent guard cell opening, and reduced water loss, with aw having opposite responses. Ethylene treatment of wild-type tomato plants increased flavonol accumulation in guard cells; however, no flavonol increases were observed in Neverripe (Nr), an ethylene receptor mutant. Consistent with lower levels of ROS due to elevated flavonols, ethylene treatments decreased ABA-induced stomatal closure in wildtype, but not Nr, with ethylene responses attenuated in the are mutant. Together these results are consistent with flavonols dampening the ABA-dependent ROS burst that drives stomatal closure and facilitating stomatal opening to modulate leaf gas exchange.
原文链接：
http://www.plantphysiol.org/content/early/2017/10/19/pp.17.01010
6NEW PHYTOLOGIST：日本理化研究所Noutoshi等人揭示水杨酸依赖性免疫作用有助于丝核菌（Rhizoctonia solani）产生抗性
Abstract
Rhizoctonia solani is a soil-borne fungus causing sheath blight. In consistent with its necrotrophic life style, no rice cultivars fully resistant to R. solani are known, and agrochemical plant defense activators used for rice blast, which upregulate a phytohormonal salicylic acid (SA)-dependent pathway, are ineffective towards this pathogen. As a result of the unavailability of genetics, the infection process of R. solani remains unclear.We used the model monocotyledonous plants Brachypodium distachyon and rice, and evaluated the effects of phytohormone-induced resistance to R. solani by pharmacological, genetic and microscopic approaches to understand fungal pathogenicity.Pretreatment with SA, but not with plant defense activators used in agriculture, can unexpectedly induce sheath blight resistance in plants. SA treatment inhibits the advancement of R. solani to the point in the infection process in which fungal biomass shows remarkable expansion and specific infection machinery is developed. The involvement of SA in R. solani resistance is demonstrated by SA-deficient NahG transgenic rice and the sheath blight-resistant B. distachyon accessions, Bd3-1 and Gaz-4, which activate SA-dependent signaling on inoculation.Our findings suggest a hemi-biotrophic nature of R. solani, which can be targeted by SA-dependent plant immunity. Furthermore, B. distachyon provides a genetic resource that can confer disease resistance against R. solani to plants.
原文链接：
http://onlinelibrary.wiley.com/doi/10.1111/nph.14849/full
7Plant Biotech J：西班牙马拉加大学Ávila等人揭示PpNAC1是海洋松树苯丙氨酸生物合成和利用的主要调节剂
Abstract
The transcriptional regulation of phenylalanine metabolism is particularly important in conifers, long-lived species that use large amounts of carbon in wood. Here, we show that the Pinus pinaster transcription factor, PpNAC1, is a main regulator of phenylalanine biosynthesis and utilization. A phylogenetic analysis classified PpNAC1 in the NST proteins group, and was selected for functional characterization. PpNAC1 is predominantly expressed in the secondary xylem and compression wood of adult trees. Silencing of PpNAC1in P. pinaster results in the alteration of stem vascular radial patterning and the downregulation of several genes associated with cell wall biogenesis, and secondary metabolism. Furthermore, trans-activation and EMSA analyses showed that PpNAC1 is able to activate its own expression and PpMyb4 promoter, while PpMyb4 is able to activate PpMyb8, a transcriptional regulator of phenylalanine and lignin biosynthesis in maritime pine. Together, these results suggest that PpNAC1 is a functional ortholog of the Arabidopsis SND1 and NST1 genes and support the idea that key regulators governing secondary cell wall formation could be conserved between gymnosperms and angiosperms. Understanding the molecular switches controlling wood formation is of paramount importance for fundamental tree biology and pave the way for applications in conifer biotechnology.
原文链接：
http://onlinelibrary.wiley.com/doi/10.1111/pbi.12854/full
8Plant Cell &Environ：中国农业科学院张永军等人揭示陆地棉中的萜烯合酶基因家族含有一种涉及对食草动物的直接防御反应的芳樟醇合酶GhTPS12
Abstract
Herbivore-induced terpenes have been reported to function as ecological signals in plant-insect interactions. Here we showed that insect-induced cotton volatile blends contained 16 terpenoid compounds with a relatively high level of linalool. The high diversity of terpene production is derived from a large terpene synthase (TPS) gene family. The TPS gene family of Gossypium hirsutum and G. raimondii consist of 46 and 41 members, respectively. Twelve TPS genes (GhTPS4-15) could be isolated and protein expression in E. colirevealed catalytic activity for eight GhTPS. The upregulation of the majority of these eight genes additionally supports the function of these genes in herbivore-induced volatile biosynthesis. Furthermore, transgenic Nicotiana tabacum plants overexpressing GhTPS12 were generated which produced relatively large amounts of (3S)-linalool. In choice tests, female adults of Helicoverpa armigera laid fewer eggs on transgenic plants compared with non-transformed controls. Meanwhile, Myzus persicae preferred feeding on wild-type leaves over leaves of transgenic plants. Our findings demonstrate that transcript accumulation of multiple TPS genes is mainly responsible for the production and diversity of herbivore-induced volatile terpenes in cotton. Also, these genes might play roles in plant defense, in particular, direct defense responses against herbivores.
原文链接：
http://onlinelibrary.wiley.com/doi/10.1111/pce.13088/full
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