scholarly journals Nanoimpact in Plants: Lessons from the Transcriptome

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 751
Author(s):  
Susana García-Sánchez ◽  
Michal Gala ◽  
Gabriel Žoldák

Transcriptomics studies are available to evaluate the potential toxicity of nanomaterials in plants, and many highlight their effect on stress-responsive genes. However, a comparative analysis of overall expression changes suggests a low impact on the transcriptome. Environmental challenges like pathogens, saline, or drought stress induce stronger transcriptional responses than nanoparticles. Clearly, plants did not have the chance to evolve specific gene regulation in response to novel nanomaterials; but they use common regulatory circuits with other stress responses. A shared effect with abiotic stress is the inhibition of genes for root development and pathogen response. Other works are reviewed here, which also converge on these results.

2021 ◽  
Author(s):  
Jun-E Guo

Abstract Histone deacetylation, one of vital modifying factors of post-translation modifications, which is catalyzed by histone deacetylase. The genes of histone deacetylase(HDACs) play critical roles in various stress responses. However, detailed functions for most SlHDAC members in tomato still unknown. In this work, we found that a histone deacetylase, SlHDA3, involved in response to NaCl and drought abiotic stresses. The expression of SlHDA3 was also induced significantly by NaCl, drought stress and endogenous hormone treatments. Silencing of SlHDA3 in tomato, the RNAi transgenic plants presented depressed tolerance to drought and salt stresses compared with WT tomato. The results of sensitivity analysis indicated that the length of hypocotyl and roots in RNAi plants were more inhibited by ABA and salt stress than that of WT at post-germination stage. Worse growth status were exhibited in SlHDA3 transgenic plants under salt and drought stress as are evaluated by a series of physiological parameters related to stress responses, such as decreased RWC, survival rate, ABA content, chlorophyll content and CAT activity, and increased MDA content and proline content. Besides, the expressions analysis of transgenic plants showed that the transcripts of genes which associated with responses to abiotic stress were down-regulated under salt-stressed conditions. To sum up, SlHDA3 acts as a stress-responsive gene, plays a role in the positive regulation of abiotic stress tolerance, and may be one of the new members in the engineering breeding of salt- and drought-tolerant tomato.


Author(s):  
Bo Shu ◽  
YaChao Xie ◽  
Fei Zhang ◽  
Dejian Zhang ◽  
Chunyan Liu ◽  
...  

Calmodulin-like (CML) proteins represent a diverse family of protein in plants, and play significant roles in biotic and abiotic stress responses. However, the involvement of citrus CMLs in plant responses to drought stress (abiotic stress) and arbuscular mycorrhizal fungi (AMF) colonization remain relatively unknown. We characterized the citrus CML genes by analyzing the EF-hand domains and a genome-wide search, and identified a total of 38 such genes, distributed across at least nine chromosomes. Six tandem duplication clusters were observed in the CsCMLs, and 12 CsCMLs exhibited syntenic relationships with Arabidopsis thaliana CMLs. Gene expression analysis showed that 29 CsCMLs were expressed in the roots, and exhibited differential expression patterns. The regulation of CsCMLs expression was not consistent with the cis-elements identified in their promoters. CsCML2, 3, and 5 were upregulated in response to drought stress, and AMF colonization repressed the expression of CsCML7, 9, 12, 13,20, 27, 28, and 35,and induced that of CsCML1, 2, 3, 5, 8, 10, 11, 14, 15, 16, 18, 25, 30, 33, and 37. Furthermore, AMF colonization and drought stress exerted a synergistic effect, evident from the enhanced repression of CsCML7, 9, 12, 13, 27, 28, and 35 and enhanced expression of CsCML2, 3, and 5 under AMF colonization and drought stress. The present study provides valuable insights into the CsCML gene family and its responses to AMF colonization and drought stress.


Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 722
Author(s):  
An ◽  
Ma ◽  
Du ◽  
Yu ◽  
Li ◽  
...  

ATP-binding cassette (ABC) transporters comprise a transport system superfamily which is ubiquitous in eukaryotic and prokaryotic cells. In plants, ABC transporters play important roles in hormone transport and stress tolerance. In this study, 15 BhABC transporters encoded by genes identified from the transcriptome of Betula halophila were categorized into four subfamilies (ABCB, ABCF, ABCG, and ABCI) using structural domain and phylogenetic analyses. Upon B. halophila exposure to exogenous phytohormones and abiotic stressors, gene expression patterns and transcriptional responses for each subfamily of genes were obtained using semi-quantitative RT-PCR analysis. The results demonstrated that expression of most genes belonging to ABCB and ABCG subfamilies changed in response to exogenous phytohormone exposures and abiotic stress. These results suggest that BhABC genes may participate in hormone transport and that their expression may be influenced by ABA-dependent signaling pathways involved in abiotic stress responses to various stressors.


2019 ◽  
Author(s):  
Sung Rye Park ◽  
Sim Namkoong ◽  
Zac Zezhi Zhang ◽  
Leon Friesen ◽  
Yu-Chih Chen ◽  
...  

Cancer cells often heterogeneously respond to genotoxic chemotherapy, leading to fractional killing and chemoresistance1, 2, which remain as the major obstacles in cancer treatment. It is widely believed that DNA damage induces a uniform response in regulating transcription and that cell fate is passively determined by a threshold mechanism evaluating the level of transcriptional responses3. On the contrary to this assumption, here we show that a surprisingly high level of heterogeneity exists in individual cell transcriptome responses to DNA damage, and that these transcriptome variations dictate the cell fate after DNA damage. Many DNA damage response genes, including tumor suppressor p53 targets, were exclusively expressed in only a subset of cells having specific cell fate, producing unique stress responses tailored for the fate that the cells are committed to. For instance, CDKN1A, the best known p53 target inhibiting cell cycle, was specifically expressed in a subset of cells undergoing cell cycle checkpoint, while other pro-apoptotic p53 targets were expressed only in cells undergoing apoptosis. A small group of cells exhibited neither checkpoint nor apoptotic responses, but produced a unique transcriptional program that conferred strong chemoresistance to the cells. The heterogeneous transcriptome response to DNA damage was also observed at the protein level in flow cytometry. Our results demonstrate that cell fate heterogeneity after DNA damage is mediated by distinct transcriptional programs generating fate-specific gene expression landscapes. This finding provides an important insight into understanding heterogeneous chemotherapy responses of cancer cells.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1036E-1037
Author(s):  
Mohamed Tawfik ◽  
Alejandra Ferenczi ◽  
Daniel Enter ◽  
Rebecca Grumet

Abiotic stresses (e.g., salinity, drought, cold, oxidative stress) can be major factors limiting plant productivity worldwide. We sought to increase abiotic stress resistance in cucumber by expressing the A. thaliana transcription factors CBF1and CBF3, which regulate genes responsible for enhanced dehydration-stress resistance in Arabidopsis. Our previous studies in the greenhouse and field demonstrated increased salinity tolerance in CBF-expressing cucumber lines. In the current studies, we tested response of CBF-cucumber plants to drought, chilling, and oxidative stresses. Transgenic cucumber plants subjected to drought stress in the greenhouse showed elevated levels of the stress-inducible compatible solute, proline, compared to the nontransgenic controls. Preliminary results also indicate greater photochemical efficiency in CBF-expressing plants under drought stress conditions compared to the nontransgenic controls. Under nonstressed conditions, there were no significant differences in growth between the transgenic and the nontransgenic cucumber plants; however, after a cycle of drought stress, CBF-cucumber lines had less growth reduction compared to the nontransgenic counterparts. The advantage in growth was less pronounced after a second cycle of drought. We also evaluated the transgenic cucumber plants under chilling conditions (i.e., low, nonfreezing temperatures within the 0 to 12 °C range). Based on plant height and cotyledon and leaf damage measurements, transgenic cucumber seedlings did not show chilling tolerance compared to the wild-type control. The response of transgenic CBF-cucumber plants to oxidative stress using methyl viologen is also being evaluated.


2021 ◽  
Author(s):  
MEGHA BHATT

Abstract Drought is one of the key abiotic stresses that critically influences the crops by restraining their growth and yield potential. Being sessile, plant tackle the detrimental effects of drought stress via modulating the cellular state by changing the gene expression. Such alteration of gene expression is essentially driven by the transcriptional syndicate. Transcription factors (TF) are the key regulatory protein that controls the expression of their target gene by binding to the cis-regulatory elements present in the promoter region. Myb-TF subiquitously present in all eukaryotes belong to one of the largest TF family, and play wide array of biological functions in plants including anthocyanin biosynthesis, vasculature system, cell signaling, seed maturation and abiotc stress responses. In the present study, isolation, and molecular cloning of full length Myb TF from Eleusine corocana has been performed. The isolated full-length coding sequence has 1053 bp and 350 aa was submitted to NCBI (Accession number MT312253). The transcript level of EcMYB increases under different abiotic stress treatment including dehydration, salinity, and high temperature stress. The promoter region of EcMyb1 was found to be enriched in stress-responsive cis-regulatory elements such as DRE, HSE, ABRE etc. In phylogenetic analysis, EcMyb1 appeared to have high homology with its monocot orthologs particularly Sateria italica, Hordeum vulgare, Saccharum barberi and Oryza sativa. The three-dimension protein structure was generated based on homology modeling and structural aspects were discussed. Further, Insilco analysis was conducted to explore the physiological properties, subcellular localization, potential post-translational modification sites (phosphorylation and glycosylation sites), and molecular and biological function of full-length protein. Overall, the expression profiling and Insilco analysis of EcMyb1 strongly indicated its potential role in abiotic stress response in Eleusine corocana.


2019 ◽  
Vol 20 (10) ◽  
pp. 2501 ◽  
Author(s):  
A-Li Li ◽  
Zhuang Wen ◽  
Kun Yang ◽  
Xiao-Peng Wen

MicroRNA396 (miR396) is a conserved microRNA family that targets growth-regulating factors (GRFs), which play significant roles in plant growth and stress responses. Available evidence justifies the idea that miR396-targeted GRFs have important functions in many plant species; however, no genome-wide analysis of the pitaya (Hylocereus polyrhizus) miR396 gene has yet been reported. Further, its biological functions remain elusive. To uncover the regulatory roles of miR396 and its targets, the hairpin sequence of pitaya miR396b and the open reading frame (ORF) of its target, HpGRF6, were isolated from pitaya. Phylogenetic analysis showed that the precursor miR396b (MIR396b) gene of plants might be clustered into three major groups, and, generally, a more recent evolutionary relationship in the intra-family has been demonstrated. The sequence analysis indicated that the binding site of hpo-miR396b in HpGRF6 is located at the conserved motif which codes the conserved “RSRKPVE” amino acid in the Trp–Arg–Cys (WRC) region. In addition, degradome sequencing analysis confirmed that four GRFs (GRF1, c56908.graph_c0; GRF4, c52862.graph_c0; GRF6, c39378.graph_c0 and GRF9, c54658.graph_c0) are hpo-miR396b targets that are regulated by specific cleavage at the binding site between the 10th and 11th nucleotides from the 5′ terminus of hpo-miR396b. Furthermore, quantitative real-time polymerase chain reaction (qRT-PCR) analysis showed that hpo-miR396b is down-regulated when confronted with drought stress (15% polyethylene glycol, PEG), and its expression fluctuates under other abiotic stresses, i.e., low temperature (4 ± 1 °C), high temperature (42 ± 1 °C), NaCl (100 mM), and abscisic acid (ABA; 0.38 mM). Conversely, the expression of HpGRF6 showed the opposite trend to exposure to these abiotic stresses. Taken together, hpo-miR396b plays a regulatory role in the control of HpGRF6, which might influence the abiotic stress response of pitaya. This is the first documentation of this role in pitaya and improves the understanding of the molecular mechanisms underlying the tolerance to drought stress in this fruit.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Jiabin Shen ◽  
Bo Lv ◽  
Liqiong Luo ◽  
Jianmei He ◽  
Chanjuan Mao ◽  
...  

Abstract Plants can perceive environmental changes and respond to external stressors. Here, we show that OsNAC2, a member of the NAC transcription factor family, was strongly induced by ABA and osmotic stressors such as drought and high salt. With reduced yields under drought conditions at the flowering stage, OsNAC2 overexpression lines had lower resistance to high salt and drought conditions. RNAi plants showed enhanced tolerance to high salinity and drought stress at both the vegetative and flowering stages. Furthermore, RNAi plants had improved yields after drought stress. A microarray assay indicated that many ABA-dependent stress-related genes were down-regulated in OsNAC2 overexpression lines. We further confirmed that OsNAC2 directly binds the promoters of LATE EMBRYOGENESIS ABUNDANT 3 (OsLEA3) and Stress-Activated Protein Kinases 1 (OsSAPK1), two marker genes in the abiotic stress and ABA response pathways, respectively. Our results suggest that in rice OsNAC2 regulates both abiotic stress responses and ABA-mediated responses, and acts at the junction between the ABA and abiotic stress pathways.


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