Publications by authors named "Yangjie Hu"

10 Publications

  • Page 1 of 1

Cell kinetics of auxin transport and activity in Arabidopsis root growth and skewing.

Nat Commun 2021 03 12;12(1):1657. Epub 2021 Mar 12.

School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel.

Auxin is a key regulator of plant growth and development. Local auxin biosynthesis and intercellular transport generates regional gradients in the root that are instructive for processes such as specification of developmental zones that maintain root growth and tropic responses. Here we present a toolbox to study auxin-mediated root development that features: (i) the ability to control auxin synthesis with high spatio-temporal resolution and (ii) single-cell nucleus tracking and morphokinetic analysis infrastructure. Integration of these two features enables cutting-edge analysis of root development at single-cell resolution based on morphokinetic parameters under normal growth conditions and during cell-type-specific induction of auxin biosynthesis. We show directional auxin flow in the root and refine the contributions of key players in this process. In addition, we determine the quantitative kinetics of Arabidopsis root meristem skewing, which depends on local auxin gradients but does not require PIN2 and AUX1 auxin transporter activities. Beyond the mechanistic insights into root development, the tools developed here will enable biologists to study kinetics and morphology of various critical processes at the single cell-level in whole organisms.
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http://dx.doi.org/10.1038/s41467-021-21802-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7954861PMC
March 2021

The GORKY glycoalkaloid transporter is indispensable for preventing tomato bitterness.

Nat Plants 2021 04 11;7(4):468-480. Epub 2021 Mar 11.

Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel.

Fruit taste is determined by sugars, acids and in some species, bitter chemicals. Attraction of seed-dispersing organisms in nature and breeding for consumer preferences requires reduced fruit bitterness. A key metabolic shift during ripening prevents tomato fruit bitterness by eliminating α-tomatine, a renowned defence-associated Solanum alkaloid. Here, we combined fine mapping with information from 150 resequenced genomes and genotyping a 650-tomato core collection to identify nine bitter-tasting accessions including the 'high tomatine' Peruvian landraces reported in the literature. These 'bitter' accessions contain a deletion in GORKY, a nitrate/peptide family transporter mediating α-tomatine subcellular localization during fruit ripening. GORKY exports α-tomatine and its derivatives from the vacuole to the cytosol and this facilitates the conversion of the entire α-tomatine pool to non-bitter forms, rendering the fruit palatable. Hence, GORKY activity was a notable innovation in the process of tomato fruit domestication and breeding.
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http://dx.doi.org/10.1038/s41477-021-00865-6DOI Listing
April 2021

Cell-type action specificity of auxin on Arabidopsis root growth.

Plant J 2021 May 3;106(4):928-941. Epub 2021 Apr 3.

The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, Shandong, China.

The plant hormone auxin plays a critical role in root growth and development; however, the contributions or specific roles of cell-type auxin signals in root growth and development are not well understood. Here, we mapped tissue and cell types that are important for auxin-mediated root growth and development by manipulating the local response and synthesis of auxin. Repressing auxin signaling in the epidermis, cortex, endodermis, pericycle or stele strongly inhibited root growth, with the largest effect observed in the endodermis. Enhancing auxin signaling in the epidermis, cortex, endodermis, pericycle or stele also caused reduced root growth, albeit to a lesser extent. Moreover, we established that root growth was inhibited by enhancement of auxin synthesis in specific cell types of the epidermis, cortex and endodermis, whereas increased auxin synthesis in the pericycle and stele had only minor effects on root growth. Our study thus establishes an association between cellular identity and cell type-specific auxin signaling that guides root growth and development.
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http://dx.doi.org/10.1111/tpj.15208DOI Listing
May 2021

Transcriptional Basis for Differential Thermosensitivity of Seedlings of Various Tomato Genotypes.

Genes (Basel) 2020 06 16;11(6). Epub 2020 Jun 16.

Institute of Bioinformatics, University Medicine Greifswald, D-17475 Greifswald, Germany.

Transcriptional reprograming after the exposure of plants to elevated temperatures is a hallmark of stress response which is required for the manifestation of thermotolerance. Central transcription factors regulate the stress survival and recovery mechanisms and many of the core responses controlled by these factors are well described. In turn, pathways and specific genes contributing to variations in the thermotolerance capacity even among closely related plant genotypes are not well defined. A seedling-based assay was developed to directly compare the growth and transcriptome response to heat stress in four tomato genotypes with contrasting thermotolerance. The conserved and the genotype-specific alterations of mRNA abundance in response to heat stress were monitored after exposure to three different temperatures. The transcripts of the majority of genes behave similarly in all genotypes, including the majority of heat stress transcription factors and heat shock proteins, but also genes involved in photosynthesis and mitochondrial ATP production. In turn, genes involved in hormone and RNA-based regulation, such as auxin- and ethylene-related genes, or transcription factors like HsfA6b, show a differential regulation that associates with the thermotolerance pattern. Our results provide an inventory of genes likely involved in core and genotype-dependent heat stress response mechanisms with putative role in thermotolerance in tomato seedlings.
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http://dx.doi.org/10.3390/genes11060655DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7349527PMC
June 2020

Natural variation in HsfA2 pre-mRNA splicing is associated with changes in thermotolerance during tomato domestication.

New Phytol 2020 02 14;225(3):1297-1310. Epub 2019 Nov 14.

Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, D-60438, Frankfurt am Main, Germany.

Wild relatives of crops thrive in habitats where environmental conditions can be restrictive for productivity and survival of cultivated species. The genetic basis of this variability, particularly for tolerance to high temperatures, is not well understood. We examined the capacity of wild and cultivated accessions to acclimate to rapid temperature elevations that cause heat stress (HS). We investigated genotypic variation in thermotolerance of seedlings of wild and cultivated accessions. The contribution of polymorphisms associated with thermotolerance variation was examined regarding alterations in function of the identified gene. We show that tomato germplasm underwent a progressive loss of acclimation to strong temperature elevations. Sensitivity is associated with intronic polymorphisms in the HS transcription factor HsfA2 which affect the splicing efficiency of its pre-mRNA. Intron splicing in wild species results in increased synthesis of isoform HsfA2-II, implicated in the early stress response, at the expense of HsfA2-I which is involved in establishing short-term acclimation and thermotolerance. We propose that the selection for modern HsfA2 haplotypes reduced the ability of cultivated tomatoes to rapidly acclimate to temperature elevations, but enhanced their short-term acclimation capacity. Hence, we provide evidence that alternative splicing has a central role in the definition of plant fitness plasticity to stressful conditions.
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http://dx.doi.org/10.1111/nph.16221DOI Listing
February 2020

The repressor and co-activator HsfB1 regulates the major heat stress transcription factors in tomato.

Plant Cell Environ 2019 03 11;42(3):874-890. Epub 2018 Oct 11.

Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, Frankfurt am Main, Germany.

Plants code for a multitude of heat stress transcription factors (Hsfs). Three of them act as central regulators of heat stress (HS) response in tomato (Solanum lycopersicum). HsfA1a regulates the initial response, and HsfA2 controls acquired thermotolerance. HsfB1 is a transcriptional repressor but can also act as co-activator of HsfA1a. Currently, the mode of action and the relevance of the dual function of HsfB1 remain elusive. We examined this in HsfB1 overexpression or suppression transgenic tomato lines. Proteome analysis revealed that HsfB1 overexpression stimulates the co-activator function of HsfB1 and consequently the accumulation of HS-related proteins under non-stress conditions. Plants with enhanced levels of HsfB1 show aberrant growth and development but enhanced thermotolerance. HsfB1 suppression has no significant effect prior to stress. Upon HS, HsfB1 suppression strongly enhances the induction of heat shock proteins due to the higher activity of other HS-induced Hsfs, resulting in increased thermotolerance compared with wild-type. Thereby, HsfB1 acts as co-activator of HsfA1a for several Hsps, but as a transcriptional repressor on other Hsfs, including HsfA1b and HsfA2. The dual function explains the activation of chaperones to enhance protection and regulate the balance between growth and stress response upon deviations from the homeostatic levels of HsfB1.
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http://dx.doi.org/10.1111/pce.13434DOI Listing
March 2019

Synthesis and luminescence properties of brick-shaped lanthanum-organic frameworks with mesoporous and macroporous architectures.

Luminescence 2017 Nov 16;32(7):1289-1293. Epub 2017 May 16.

Key Laboratory of Rare Earth Optoelectronic Materials and Devices, School of Chemistry and Materials Engineering, Huaihua University, Huaihua, People's Republic of China.

Generally, metal-organic frameworks (MOFs) are made up from kinds of repeating microporous structure. Here, a series of Eu ions activated terephthalate-based lanthanum-organic frameworks (La-MOFs) was synthesized by a hydrothermal reaction. By controlling the reaction time, we obtained some unique brick-shaped La-MOFs in a micron scale size range, and these La-MOFs showed tunable mesoporous and macroporous architectures. It is speculated that the change in the composition and structure of building units results in the formation of this mesoporous and macroporous heterogeneous architectures. Powder X-ray diffraction patterns and Eu luminescence behavior support the speculation.
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http://dx.doi.org/10.1002/bio.3323DOI Listing
November 2017

Alternative splicing in tomato pollen in response to heat stress.

DNA Res 2017 Apr;24(2):205-217

Department of Biosciences, Molecular Cell Biology of Plants.

Alternative splicing (AS) is a key control mechanism influencing signal response cascades in different developmental stages and under stress conditions. In this study, we examined heat stress (HS)-induced AS in the heat sensitive pollen tissue of two tomato cultivars. To obtain the entire spectrum of HS-related AS, samples taken directly after HS and after recovery were combined and analysed by RNA-seq. For nearly 9,200 genes per cultivar, we observed at least one AS event under HS. In comparison to control, for one cultivar we observed 76% more genes with intron retention (IR) or exon skipping (ES) under HS. Furthermore, 2,343 genes had at least one transcript with IR or ES accumulated under HS in both cultivars. These genes are involved in biological processes like protein folding, gene expression and heat response. Transcriptome assembly of these genes revealed that most of the alternative spliced transcripts possess truncated coding sequences resulting in partial or total loss of functional domains. Moreover, 141 HS specific and 22 HS repressed transcripts were identified. Further on, we propose AS as layer of stress response regulating constitutively expressed genes under HS by isoform abundance.
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http://dx.doi.org/10.1093/dnares/dsw051DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5397606PMC
April 2017

Unfolded protein response in pollen development and heat stress tolerance.

Plant Reprod 2016 06 29;29(1-2):81-91. Epub 2016 Mar 29.

Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, 60438, Frankfurt am Main, Germany.

Key Message: Importance of the UPR for pollen. Pollen is particularly sensitive to environmental conditions that disturb protein homeostasis, such as higher temperatures. Their survival is dependent on subcellular stress response systems, one of which maintains protein homeostasis in the endoplasmic reticulum (ER). Disturbance of ER proteostasis due to stress leads to the activation of the unfolded protein response (UPR) that mitigates stress damage mainly by increasing ER-folding capacity and reducing folding demands. The UPR is controlled by ER membrane-associated transcription factors and an RNA splicing factor. They are important components of abiotic stress responses including general heat stress response and thermotolerance. In addition to responding to environmental stresses, the UPR is implicated in developmental processes required for successful male gametophyte development and fertilization. Consequently, defects in the UPR can lead to pollen abortion and male sterility. Several UPR components are involved in the elaboration of the ER network, which is required for pollen germination and polar tube growth. Transcriptome and proteome analyses have shown that components of the ER-folding machinery and the UPR are upregulated at specific stages of pollen development supporting elevated demands for secretion. Furthermore, genetic studies have revealed that knockout mutants of UPR genes are defective in producing viable or competitive pollen. In this review, we discuss recent findings regarding the importance of the UPR for both pollen development and stress response.
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http://dx.doi.org/10.1007/s00497-016-0276-8DOI Listing
June 2016

HsfA2 Controls the Activity of Developmentally and Stress-Regulated Heat Stress Protection Mechanisms in Tomato Male Reproductive Tissues.

Plant Physiol 2016 04 25;170(4):2461-77. Epub 2016 Feb 25.

Department of Biosciences, Molecular Cell Biology of Plants, Goethe University, D-60438 Frankfurt am Main, Germany (S.F., A.M., S.S., Y.H., P.P., S.K.M., E.S., K.-D.S.);Cluster of Excellence Frankfurt, Goethe University, D-60438 Frankfurt am Main, Germany (S.S., E.S.);Plant Breeding, Wageningen University, Wageningen 6708PB, The Netherlands (M.J.P., A.B.);Leibniz Institute of Plant Biochemistry, D-06120 Halle (Saale), Germany (B.T., K.-D.S.);Max Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany (K.T.); andBuchmann Institute for Molecular Life Sciences, Goethe University, D-60438 Frankfurt am Main, Germany (E.S.)

Male reproductive tissues are more sensitive to heat stress (HS) compared to vegetative tissues, but the basis of this phenomenon is poorly understood. Heat stress transcription factors (Hsfs) regulate the transcriptional changes required for protection from HS In tomato (Solanum lycopersicum), HsfA2 acts as coactivator of HsfA1a and is one of the major Hsfs accumulating in response to elevated temperatures. The contribution of HsfA2 in heat stress response (HSR) and thermotolerance was investigated in different tissues of transgenic tomato plants with suppressed HsfA2 levels (A2AS). Global transcriptome analysis and immunodetection of two major Hsps in vegetative and reproductive tissues showed that HsfA2 regulates subsets of HS-induced genes in a tissue-specific manner. Accumulation of HsfA2 by a moderate HS treatment enhances the capacity of seedlings to cope with a subsequent severe HS, suggesting an important role for HsfA2 in regulating acquired thermotolerance. In pollen, HsfA2 is an important coactivator of HsfA1a during HSR HsfA2 suppression reduces the viability and germination rate of pollen that received the stress during the stages of meiosis and microspore formation but had no effect on more advanced stages. In general, pollen meiocytes and microspores are characterized by increased susceptibility to HS due to their lower capacity to induce a strong HSR This sensitivity is partially mitigated by the developmentally regulated expression of HsfA2 and several HS-responsive genes mediated by HsfA1a under nonstress conditions. Thereby, HsfA2 is an important factor for the priming process that sustains pollen thermotolerance during microsporogenesis.
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http://dx.doi.org/10.1104/pp.15.01913DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4825147PMC
April 2016
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