bims-pisump 2018-05-13 papers

on Pisum

Issue of 2018‒05‒13
seven papers selected by
Vera S. Bogdanova
Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences

Genetic improvement of the shoot architecture and yield in soybean plants via the manipulation of GmmiR156b.
A Molecular Framework for Auxin-Controlled Homeostasis of Shoot Stem Cells in Arabidopsis.
ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1) affects development, photosynthesis, and hormonal homeostasis in hybrid aspen (Populus tremula L. × P. tremuloides).
Genome-wide evidence for divergent selection between populations of a major agricultural pathogen.
Ectopic expression of ORANGE promotes carotenoid accumulation and fruit development in tomato.
Comparative metabolomic analysis of seed metabolites associated with seed storability in rice (Oryza sativa L.) during natural aging.
A single point mutation on the cucumber mosaic virus surface induces an unexpected and strong interaction with the F1 complex of the ATP synthase in Nicotiana clevelandii plants.

Plant Biotechnol J. 2018 May 05.

Genetic improvement of the shoot architecture and yield in soybean plants via the manipulation of GmmiR156b.

Zhengxi Sun, Chao Su, Jinxia Yun, Qiong Jiang, Lixiang Wang, Youning Wang, Dong Cao, Fang Zhao, Qingsong Zhao, Mengchen Zhang, Bin Zhou, Lei Zhang, Fanjiang Kong, Baohui Liu, Yiping Tong, Xia Li.

  The optimization of plant architecture in order to breed high-yielding soybean cultivars is a goal of researchers. Tall plants bearing many long branches are desired, but only modest success in reaching these goals has been achieved. MicroRNA156 (miR156)-SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) gene modules play pivotal roles in controlling shoot architecture and other traits in crops like rice and wheat. However, the effects of miR156-SPL modules on soybean architecture and yield, and the molecular mechanisms underlying these effects, remain largely unknown. In this study, we achieved substantial improvements in soybean architecture and yield by overexpressing GmmiR156b. Transgenic plants produced significantly increased numbers of long branches, nodes, and pods, and they exhibited an increased 100-seed weight, resulting in a 46-63% increase in yield per plant. Intriguingly, GmmiR156b overexpression had no significant impact on plant height in a growth room or under field conditions; however, it increased stem thickness significantly. Our data indicate that GmmiR156b modulates these traits mainly via the direct cleavage of SPL transcripts. Moreover, we found that GmSPL9d is expressed in the shoot apical meristem and axillary meristems of soybean, and that GmSPL9d may regulate axillary bud formation and branching by physically interacting with the homeobox gene WUSCHEL (WUS), a central regulator of axillary meristem formation. Together, our results identify GmmiR156b as a promising target for the improvement of soybean plant architecture and yields, and they reveal a new and conserved regulatory cascade involving miR156-SPL-WUS that will help researchers decipher the genetic basis of plant architecture. This article is protected by copyright. All rights reserved.

Keywords:   GmmiR156 ; SPL ; Soybean; plant architecture; shoot branching; yield

DOI:  https://doi.org/10.1111/pbi.12946
Mol Plant. 2018 May 03. pii: S1674-2052(18)30156-4. [Epub ahead of print]

A Molecular Framework for Auxin-Controlled Homeostasis of Shoot Stem Cells in Arabidopsis.

Linjie Luo, Jian Zeng, Haijun Wu, Zhaoxia Tian, Zhong Zhao.

  The classic phytohormone auxin plays essential roles in priming meristematic cell differentiation in the shoot apical meristem to promote lateral organ initiation. Recently, several lines of evidence have suggested that auxin not only is transported to new primordia but also descends in stem cells in the central zone. However, the function of auxin in stem cell regulation has remained elusive. Here, we show that auxin signaling in stem cells is mediated, at least in part, by AUXIN RESPONSE FACTOR5/MONOPTEROS (MP), which directly represses the transcription of DORNROSCHEN/ENHANCER OF SHOOT REGENERATION 1 (DRN/ESR1). DRN expressed in stem cells positively regulates CLV3 expression and has important meristematic functions. Our results provide a mechanistic framework for auxin control of shoot stem cell homeostasis and demonstrate how auxin differs in the control of plant stem cell maintenance and differentiation.

Keywords:  DORNROSCHEN; MONOPTEROS; auxin; stem cell homeostasis

DOI:  https://doi.org/10.1016/j.molp.2018.04.006
J Plant Physiol. 2018 Apr 25. pii: S0176-1617(18)30123-8. [Epub ahead of print]226 91-102

ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1) affects development, photosynthesis, and hormonal homeostasis in hybrid aspen (Populus tremula L. × P. tremuloides).

Maciej Jerzy Bernacki, Weronika Czarnocka, Damian Witoń, Anna Rusaczonek, Magdalena Szechyńska-Hebda, Ireneusz Ślesak, Joanna Dąbrowska-Bronk, Stanisław Karpiński.

  ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1) was first described as a protein involved in salicylic acid (SA)-, ethylene-, and reactive oxygen species (ROS)-dependent defense and acclimation responses. It is a molecular regulator of biotic and abiotic stress-induced programmed cell death. Its role is relatively well known in annual plants, such as Arabidopsis thaliana or Nicotiana benthamiana. However, little is known about its functions in woody plants. Therefore, in this study, we aimed to characterize the function of EDS1 in the Populus tremula L. × P. tremuloides hybrid grown for several seasons in the natural environment. We used two transgenic lines, eds1-7 and eds1-12, with decreased EDS1 expression levels in this study. The observed changes in physiological and biochemical parameters corresponded with the EDS1 silencing level. Both transgenic lines produced more lateral shoots in comparison to the wild-type (WT) plants, which resulted in the modification of tree morphology. Photosynthetic parameters, such as quantum yield of photosystem II (ϕPSII), photochemical and non-photochemical quenching (qP and NPQ, respectively), as well as chlorophyll content were found to be increased in both transgenic lines, which resulted in changes in photosynthetic efficiency. Our data also revealed lower foliar concentrations of SA and ROS, the latter resulting most probably from more efficient antioxidant system in both transgenic lines. In addition, our data indicated significantly decreased rate of leaf senescence during several autumn seasons. Transcriptomic analysis revealed deregulation of 2215 and 376 genes in eds1-12 and eds1-7, respectively, and also revealed 207 genes that were commonly deregulated in both transgenic lines. The deregulation was primarily observed in the genes involved in photosynthesis, signaling, hormonal metabolism, and development, which was found to agree with the results of biochemical and physiological tests. In general, our data proved that poplar EDS1 affects tree morphology, photosynthetic efficiency, ROS and SA metabolism, as well as leaf senescence.

Keywords:  Development; Photosynthesis; Poplar; Salicylic acid; Senescence; Tree morphology

DOI:  https://doi.org/10.1016/j.jplph.2018.04.014
Mol Ecol. 2018 May 05.

Genome-wide evidence for divergent selection between populations of a major agricultural pathogen.

Fanny E Hartmann, Bruce A McDonald, Daniel Croll.

The genetic and environmental homogeneity in agricultural ecosystems is thought to impose strong and uniform selection pressures. However, the impact of this selection on plant pathogen genomes remains largely unknown. We aimed to identify the proportion of the genome and the specific gene functions under positive selection in populations of the fungal wheat pathogen Zymoseptoria tritici. First, we performed genome scans in four field populations that were sampled from different continents and on distinct wheat cultivars to test which genomic regions are under recent selection. Based on extended haplotype homozygosity and composite likelihood ratio tests, we identified 384 and 81 selective sweeps affecting 4% and 0.5% of the 35 Mb core genome, respectively. We found differences both in the number and position of selective sweeps across the genome between populations. Using a XtX-based outlier detection approach, we identified 51 extremely divergent genomic regions between the allopatric populations, suggesting that divergent selection led to locally adapted pathogen populations. We performed an outlier detection analysis between two sympatric populations infecting two different wheat cultivars to identify evidence for host-driven selection. Selective sweep regions harbored genes that are likely to play a role in successfully establishing host infections. We also identified secondary metabolite gene clusters and an enrichment in genes encoding transporter and protein localization functions. The latter gene functions mediate responses to environmental stress, including interactions with the host. The distinct gene functions under selection indicate that both local host genotypes and abiotic factors contributed to local adaptation. This article is protected by copyright. All rights reserved.

DOI: https://doi.org/10.1111/mec.14711
Plant Biotechnol J. 2018 May 05.

Ectopic expression of ORANGE promotes carotenoid accumulation and fruit development in tomato.

Mohammad Yazdani, Zhaoxia Sun, Hui Yuan, Shaohua Zeng, Theodore W Thannhauser, Julia Vrebalov, Qiyue Ma, Yimin Xu, Zhangjun Fei, Joyce Van Eck, Shiping Tian, Yaakov Tadmor, James J Giovannoni, Li Li.

  Carotenoids are critically important to plants and humans. The ORANGE (OR) gene is a key regulator for carotenoid accumulation, but its physiological roles in crops remain elusive. In this study, we generated transgenic tomato ectopically overexpressing the Arabidopsis wild type OR (AtORWT ) and a 'golden SNP'-containing OR (AtORHis ). We found that AtORHis initiated chromoplast formation in very young fruit and stimulated carotenoid accumulation at all fruit developmental stages, uncoupled from other ripening activities. The elevated levels of carotenoids in the AtOR lines were distributed in the same sub-plastidial fractions as in wild type tomato, indicating an adaptive response of plastids to sequester the increased carotenoids. Microscopic analysis revealed that the plastid sizes were increased in both AtORWT and AtORHis lines at early fruit developmental stages. Moreover, AtOR overexpression promoted early flowering, fruit set, and seed production. Ethylene production and the expression of ripening-associated genes were also significantly increased in the AtOR transgenic fruit at ripening stages. RNA-Seq transcriptomic profiling highlighted the primary effects of OR overexpression on the genes in the processes related to RNA, protein, and signalling in tomato fruit. Taken together, these results expand our understanding of OR in mediating carotenoid accumulation in plants and suggest additional roles of OR in affecting plastid size as well as flower and fruit development, thus making OR a target gene not only for nutritional biofortification of agricultural products but also for alteration of horticultural traits. This article is protected by copyright. All rights reserved.

Keywords:   OR ; carotenoids; early flowering; fruit set; plastids; tomato

DOI:  https://doi.org/10.1111/pbi.12945
Plant Physiol Biochem. 2018 May 01. pii: S0981-9428(18)30178-5. [Epub ahead of print]127 590-598

Comparative metabolomic analysis of seed metabolites associated with seed storability in rice (Oryza sativa L.) during natural aging.

Shijuan Yan, Wenjie Huang, Jiadong Gao, Hua Fu, Jun Liu.

  Seed storability is an important trait for crop breeding, however, the mechanism underlying seed storability remains largely unknown. Here, a mass spectrometry-based comparative metabolomic study was performed for rice seeds before and after 24-month natural storage between two hybrid rice cultivars, IIYou 998 (IIY) with low storability and BoYou 998 (BY) with relative high storability. A total of 48 metabolites among 90 metabolite peaks detected were conclusively identified, and most of them are involved in the primary metabolism. During the 24-month storage, 19 metabolites with significant changes in abundance were found in the storage-sensitive IIY seeds, but only 8 in the BY seeds, most of which are free amino acids and soluble sugars. The observed changes of the metabolites in IIY seeds that are consistent with our protoemics results are likely to be involved in its sensitivity to storage. Levels of all identified 18 amino acid-related metabolites and most sugar-related metabolites were significantly higher in IIY seeds both before and after storage. However the level of raffinose was lower in IIY seeds before and after storage, and did not change significantly throughout the storage period in both two cultivars, suggesting its potential role in seed storability. Taken together, these results may help to improve our understanding of seed storability.

Keywords:  Chemical compounds; Fuctose; GC-MS; Glucose; Leucine; Lysine; Metabolomics; Methionine; Oryza sativa L; PubChem CID: 10542; PubChem CID: 5793; PubChem CID: 5962; PubChem CID: 5984; PubChem CID: 5988; PubChem CID: 6106; PubChem CID: 6137; PubChem CID: 6287; PubChem CID: 6288; PubChem CID: 6305; Raffinose; Storability; Sucrose; Threonine; Tryptophan; Valine

DOI:  https://doi.org/10.1016/j.plaphy.2018.04.020
Virus Res. 2018 May 03. pii: S0168-1702(18)30092-3. [Epub ahead of print]

A single point mutation on the cucumber mosaic virus surface induces an unexpected and strong interaction with the F1 complex of the ATP synthase in Nicotiana clevelandii plants.

Ákos Gellért, Tímea Pósa, Attila Fábián, László Szabó, Károly Bóka, Barbara Forró, Katalin Salánki, László Drahos, Eszter Tóth, Angéla Juhász, Ervin Balázs.

  A previous study showed that a single amino acid difference in the cucumber mosaic virus (CMV) capsid protein (CP) elicits unusual symptoms. The wild-type strain (CMV-R) induces green mosaic symptoms and malformation while the mutant strain (CMV-R3E79R) causes chlorotic lesions on inoculated leaves and strong stunting with necrosis on systemic leaves. Virion preparations of CMV-R and CMV-R3E79R were partially purified from Nicotiana clevelandii A. Gray and analysed by two-dimensional gel electrophoresis. Their separated protein patterns showed remarkable differences at the 50-75 kDa range, both in numbers and intensity of spots, with more protein spots for the mutant CMV. Mass spectrometry analysis demonstrated that the virion preparations contained host proteins identified as ATP synthase alpha and beta subunits as well as small and large Rubisco subunits, respectively. Virus overlay protein binding assay (VOPBA), immunogold electron microscopy and modified ELISA experiments were used to prove the direct interaction between the virus particle and the N. clevelandii ATP synthase F1 motor complex. Protein-protein docking study revealed that the electrostatic change in the mutant CMV can introduce stronger interactions with ATP synthase F1 complex. Based on our findings we suggest that the mutation present in the CP can have a direct effect on the long-distance movement and systemic symptoms. In molecular view the mutant CMV virion can lethally block the rotation of the ATP synthase F1 motor complex which may lead to cell apoptosis, and finally to plant death.

Keywords:  ATP synthase; Capsid protein; Cucumber mosaic virus; Host-virus interaction; Nicotiana clevelandii

DOI:  https://doi.org/10.1016/j.virusres.2018.05.005