Ectopic Expression of Os-miR408 Improves Thermo-Tolerance of Perennial Ryegrass

With global warming, high temperature stress has become a main threat to the growth of cool-season turfgrasses, including perennial ryegrass. As one of the conserved plant microRNA families, miR408s are known to play roles in various abiotic stresses, including cold, drought, salinity, and oxidative stress, but no report, thus far, was found for heat. Here, perennial ryegrass plants overexpressing rice Os-miR408 were used to investigate the role of miR408 in plant heat tolerance. Both wild type (WT) and miR408 transgenic perennial ryegrass plants (TG) were subjected to short-term heat stress at 38 °C for 72 h (experiment 1) or at 42 °C for 48 h (experiment 2), and then let recover for 7 days at optimum temperature. Morphological changes and physiological parameters, including antioxidative responses of TG and WT plants, were compared. The results showed that miR408 downregulated the expression of two putative target genes, PLASTOCYANIN and LAC3. Additionally, overexpression of Os-miR408 improved thermo-tolerance of perennial ryegrass, demonstrated by lower leaf lipid peroxidation and electrolyte leakage, and higher relative water content after both 38 and 42 °C heat stresses. In addition, the enhanced thermotolerance of TG plants could be associated with its morphological changes (e.g., narrower leaves, smaller tiller angles) and elevated antioxidative capacity. This study is the first that experimentally reported a positive role of miR408 in plant tolerance to heat stress, which provided useful information for further understanding the mechanism by which miR408 improved plant high-temperature tolerance, and offered a potential genetic resource for breeding heat-resistant cool-season turfgrass in the future.

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Role of salicylic acid in heat stress tolerance in tri-genomic Brassica napus L.

Enero-Abril 2021 - Bioagro ◽

10.51372/bioagro331.2 ◽

2020 ◽

Vol 33 (1) ◽

pp. 13-20

Author(s):

Muhammad Awais Ghani ◽

Muhammad Mehran Abbas ◽

Basharat Ali ◽

Khurram Ziaf ◽

Muhammad Azam ◽

...

Keyword(s):

Salicylic Acid ◽

Heat Stress ◽

High Temperature ◽

Brassica Napus ◽

Biochemical Analysis ◽

Foliar Application ◽

Brassica Napus L ◽

Elevated Activity ◽

Heat Stress Tolerance

Tri-genomic Brassica napus L.wasdeveloped by the cross between Brassica napusand Brassica nigra. The crop is animportant source of vegetable seed oil in Pakistan,after cotton. The low oilseed rape yield is attributed to high temperature in the production zones. Interspecific hybridization using these two speciescan be helpful to produce heat resistant hybrids. On the other hand, it has been found that foliar application of different plant growth regulators can be used to reduce the heat stress in Brassica. The objectiveof this studywas to test the response of three different tri-genomic hybrids to high temperature stressat seedling stage. Seedlings were foliar sprayed with 0.13 mM salicylic acid (SA) prior to exposure tohigh temperatureat two true leaf stage. The plants were harvested after 30 days of sowing for growth and biochemical analysis. Plants ofV38 showed the highest values for all morphological traits and biochemical activities among the threehybrids. In general, plants exposed to the temperature stress exhibited a significant decline in growth, chlorophyll content and enzyme activity.Foliar application of SA significantly improved leaf and root biomass under heat stress.Further, antioxidativeenzyme activities significantly increased in response to SA either compared to control or to plants exposed to temperature stress.It is concluded thatapplication of salicylic acid elevated activity of antioxidative enzymes and was helpful in mitigating the detrimental effects of high temperature inoil seed rape.

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Heat and cold stresses phenotypes of Arabidopsis thaliana calmodulin mutants: regulation of gamma-aminobutyric acid shunt pathway under temperature stress

International Journal of Plant Biology ◽

10.4081/pb.2012.e2 ◽

2012 ◽

Vol 3 (1) ◽

pp. 2 ◽

Cited By ~ 6

Author(s):

Nisreen A. AL-Quraan ◽

Robert D. Locy ◽

Narendra K. Singh

Keyword(s):

Arabidopsis Thaliana ◽

Heat Stress ◽

High Temperature ◽

Seed Germination ◽

Oxidative Damage ◽

Temperature Stress ◽

Wild Type ◽

Gaba Shunt ◽

Heat And Cold Stress

Plants have evolved mechanisms to cope with changes in surrounding temperatures. T-DNA insertions in seven calmodulin genes of Arabidopsis thaliana were used to investigate the role of specific calmodulin isoforms in tolerance of plants to low and high temperature for seed germination, susceptibility to low and high temperature induced oxidative damage, and changes in the levels of gammaaminobutyric acid (GABA) shunt metabolites in response to temperature stress. Exposure of wild type (WT) and cam mutant seeds at 4°C showed reduction in germination of cam5-4 and cam6-1 seeds. Exposure of cam seedlings to 42°C for 2 hr showed reduction in seed germination and survival of seedlings in cam5-4 and cam6-1 mutants compared to WT and other cam mutants. Oxidative damage by heat and cold stress measured as the level of malonaldehyde (MDA) was detected increased in root and shoot tissues of cam5- 4 and cam6-1. Oxidative damage by heat measured as the level of MDA was detected in root and shoot of most cam mutants with highest levels in cam5-4 and cam6-1. Level of GABA shunt metabolites in seedlings were gradually increased after 1 hr and 3 hr with maximum level after 6 hr and 12 hr treatments at 4ºC. GABA shunt metabolites in both root and shoot were generally elevated after 30 min and 1 hr treatment at 42°C, and increased substantially after 2 hr at 42°C comparing to the control (no treatment). GABA and glutamate levels were increased significantly more than alanine in root and shoot tissues of all cam mutants and wild type compared to the control. Alanine levels showed significant decreases in all cam mutants and in WT for 30 and 60 min of heat stress. Sensitivity of cam5-4 and cam6-1 to low temperatures suggests a role of the CAM5 and CAM6 genes in seed germination and protection against cold induced oxidative damage. Increases in the level of GABA shunt metabolites in response to cold treatment after initial reduction in some cam mutants suggests a role for calmodulin protein (cam) in the activation of glutamate decarboxylase (GAD) after exposure to cold, while increased metabolite levels may indicate involvement of other factors like reduction in cytoplasmic pH in cold regulation. Initial general elevation in GABA shunt metabolites after 30 min heat treatment in cam mutants suggests regulation of GABA level by cam. These data suggest that regulation by factors other than cam is likely, and that this factor may relate to the regulation of GAD by intracellular pH and/or metabolite partitioning under heat stress.

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The Improvement of Thermotolerance in Tall Fescue and Perennial Ryegrass by Activating the Antioxidative System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.610-613.249 ◽

2012 ◽

Vol 610-613 ◽

pp. 249-253 ◽

Cited By ~ 1

Author(s):

Jie Zhang ◽

Yan Wang ◽

Hong Fei Yang ◽

Jian Long Li

Keyword(s):

Heat Stress ◽

Antioxidative Enzymes ◽

Perennial Ryegrass ◽

Tall Fescue ◽

Festuca Arundinacea ◽

Guaiacol Peroxidase ◽

Cool Season ◽

Pre Treatment ◽

And Control ◽

Gpx Activity

The effect of hydrogen peroxide (H2O2) of low concentration on thermotolerance of tall fescue (Festuca arundinacea cv. Barlexas) and perennial ryegrass (Lolium perenne cv. Accent) was studied following a foliar pretreatment with 10 mM H2O2. Antioxidative enzymes activities and antioxidant content were measured in both cool-season turfgrass cultivars under heat stress (38/30 °C, day/night) and control normal temperature (26/15 °C, day/night). While activities of catalase(CAT), guaiacol peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR) and glutathione-dependent peroxidases (GPX) were enhanced by H2O2pretreatment during heat stress. APX, GR and GPX activities were significantly enhanced during heat stress. These were likely the most important antioxidative enzymes in tall fescue and perennial ryegrass protecting plants against heat stress. The thermotolerance was also concomitant with an increased glutathione pool, as evaluated by the significant increase of the total glutathione pool in two pretreated cultivars. The increase of POD, CAT, APX, GR activities and significant increase of GPX activity prior to the initiation of heat stress in pre-treatment plants suggested a possible role for H2O2as a signaling molecule protecting them against the subsequent heat-induced damage.

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The role of brinker in mediating the graded response to Dpp in early Drosophila embryos

Development ◽

10.1242/dev.126.15.3323 ◽

1999 ◽

Vol 126 (15) ◽

pp. 3323-3334 ◽

Cited By ~ 11

Author(s):

A. Jazwinska ◽

C. Rushlow ◽

S. Roth

Keyword(s):

Target Gene ◽

Target Genes ◽

Gene Activation ◽

Ectopic Expression ◽

Intermediate Level ◽

Graded Response ◽

High Level ◽

Drosophila Embryos ◽

Novel Protein

Brinker (Brk), a novel protein with features of a transcriptional repressor, regulates the graded response to Decapentaplegic (Dpp) in appendage primordia of Drosophila. Here, we show that in the embryo brk also has differential effects on Dpp target genes, depending on the level of Dpp activity required for their activation. Low-level target genes, like dpp itself, tolloid and early zerknullt, show strong ectopic expression in ventrolateral regions of brk mutant embryos; intermediate-level target genes like pannier show weak ectopic expression, while high-level target genes like u-shaped and rhomboid are not affected. Ectopic target gene activation in the absence of brk is independent of Dpp, Tkv and Medea, indicating that Dpp signaling normally antagonizes brk's repression of these target genes. brk is expressed like short gastrulation (sog) in ventrolateral regions of the embryo abutting the dpp domain. Here, both brk and sog antagonize the antineurogenic activity of Dpp so that only in brk sog double mutants is the neuroectoderm completely deleted.

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Sonic hedgehog is an endodermal signal inducing Bmp-4 and Hox genes during induction and regionalization of the chick hindgut

Development ◽

10.1242/dev.121.10.3163 ◽

1995 ◽

Vol 121 (10) ◽

pp. 3163-3174 ◽

Cited By ~ 80

Author(s):

D.J. Roberts ◽

R.L. Johnson ◽

A.C. Burke ◽

C.E. Nelson ◽

B.A. Morgan ◽

...

Keyword(s):

Sonic Hedgehog ◽

Target Genes ◽

Hox Genes ◽

Ectopic Expression ◽

Secreted Protein ◽

Gut Development ◽

Visceral Mesoderm ◽

Homologous Genes ◽

Inductive Signal

Reciprocal inductive signals between the endoderm and mesoderm are critical to vertebrate gut development. Sonic hedgehog encodes a secreted protein known to act as an inductive signal in several regions of the developing embryo. In this report, we provide evidence to support the role of Sonic hedgehog and its target genes Bmp-4 and the Abd-B-related Hox genes in the induction and patterning the chick hindgut. Sonic is expressed in the definitive endoderm at the earliest stage of chick gut formation. Immediately subjacent to Sonic expression in the caudal endoderm is undifferentiated mesoderm, later to become the visceral mesoderm of the hindgut. Genes expressed within this tissue include Bmp-4 (a TGF-beta relative implicated in proper growth of visceral mesoderm) and members of the Abd-B class of Hox genes (known regulators of pattern in many aspects of development). Using virally mediated misexpression, we show that Sonic hedgehog is sufficient to induce ectopic expression of Bmp-4 and specific Hoxd genes within the mesoderm. Sonic therefore appears to act as a signal in an epithelial-mesenchymal interaction in the earliest stages of chick hindgut formation. Gut pattern is evidenced later in gut morphogenesis with the presence of anatomic boundaries reflecting phenotypically and physiologically distinct regions. The expression pattern of the Abd-b-like Hox genes remains restricted in the hindgut and these Hox expression domains reflect gut morphologic boundaries. This finding strongly supports a role for these genes in determining the adult gut phenotype. Our results provide the basis for a model to describe molecular controls of early vertebrate hindgut development and patterning. Expression of homologous genes in Drosophila suggest that aspects of gut morphogenesis may be regulated by similar inductive networks in the two organisms.

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Plant tolerance to high temperature in a changing environment: scientific fundamentals and production of heat stress-tolerant crops

Frontiers in Plant Science ◽

10.3389/fpls.2013.00273 ◽

2013 ◽

Vol 4 ◽

Cited By ~ 537

Author(s):

Craita E. Bita ◽

Tom Gerats

Keyword(s):

Heat Stress ◽

High Temperature ◽

Plant Tolerance ◽

Changing Environment

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Different MicroRNA Families Involved in Regulating High Temperature Stress Response during Cotton (Gossypium hirsutum L.) Anther Development

International Journal of Molecular Sciences ◽

10.3390/ijms21041280 ◽

2020 ◽

Vol 21 (4) ◽

pp. 1280

Author(s):

Jin Chen ◽

Ao Pan ◽

Shujun He ◽

Pin Su ◽

Xiaoling Yuan ◽

...

Keyword(s):

High Temperature ◽

Stress Response ◽

Target Genes ◽

Developmental Stages ◽

High Temperature Stress ◽

Small Rna Sequencing ◽

Plant Tolerance ◽

Gossypium Hirsutum L ◽

Response Characteristics ◽

Expression Abundance

MicroRNAs (miRNAs) are small molecule RNAs widely involved in responses to plant abiotic stresses. We performed small RNA sequencing of cotton anthers at four developmental stages under normal and high temperature (NT and HT, respectively) conditions to investigate the stress response characteristics of miRNA to HT. A total of 77 miRNAs, including 33 known miRNAs and 44 novel miRNAs, were identified, and 41 and 28 miRNAs were differentially expressed under NT and HT stress conditions, respectively. The sporogenous cell proliferation (SCP), meiotic phase (MP), microspore release period (MRP), and pollen maturity (PM) stages had 10 (including 12 miRNAs), four (including six miRNAs), four (including five miRNAs), and seven (including 11 miRNAs) HT stress-responsive miRNA families, respectively, which were identified after removing the changes in genotype-specific miRNAs under NT condition. Seven miRNA families (miR2949, miR167, and miR160 at the SCP stage; miR156 and miR172 at the MP stage; miR156 at the MRP stage; and miR393 and miR3476 at the PM stage), which had expression abundance of more than 10% of the total expression abundance, served as the main regulators responding to HT stress with positive or negative regulation patterns. These miRNAs orchestrated the expression of the corresponding target genes and led to different responses in the HT-tolerant and the HT-sensitive lines. The results revealed that the HT stress response of miRNAs in cotton anthers were stage-specific and differed with the development of anthers. Our study may enhance the understanding of the response of miRNAs to HT stress in cotton anthers and may clarify the mechanism of plant tolerance to HT stress.

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CircPTPRA blocks the recognition of RNA N6-methyladenosine through interacting with IGF2BP1 to suppress bladder cancer progression

Molecular Cancer ◽

10.1186/s12943-021-01359-x ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Fei Xie ◽

Chao Huang ◽

Feng Liu ◽

Hui Zhang ◽

Xingyuan Xiao ◽

...

Keyword(s):

Bladder Cancer ◽

Cancer Progression ◽

Molecular Mechanisms ◽

Target Genes ◽

Ectopic Expression ◽

Migration And Invasion ◽

Circular Rnas ◽

Clinical Role ◽

Rna Immunoprecipitation

Abstract Background Circular RNAs (circRNAs) have been found to have significant impacts on bladder cancer (BC) progression through various mechanisms. In this study, we aimed to identify novel circRNAs that regulate the function of IGF2BP1, a key m6A reader, and explore the regulatory mechanisms and clinical significances in BC. Methods Firstly, the clinical role of IGF2BP1 in BC was studied. Then, RNA immunoprecipitation sequencing (RIP-seq) analysis was performed to identify the circRNAs interacted with IGF2BP1 in BC cells. The overall biological roles of IGF2BP1 and the candidate circPTPRA were investigated in both BC cell lines and animal xenograft studies. Subsequently, we evaluated the regulation effects of circPTPRA on IGF2BP1 and screened out its target genes through RNA sequencing. Finally, we explored the underlying molecular mechanisms that circPTPRA might act as a blocker in recognition of m6A. Results We demonstrated that IGF2BP1 was predominantly binded with circPTPRA in the cytoplasm in BC cells. Ectopic expression of circPTPRA abolished the promotion of cell proliferation, migration and invasion of BC cells induced by IGF2BP1. Importantly, circPTPRA downregulated IGF2BP1-regulation of MYC and FSCN1 expression via interacting with IGF2BP1. Moreover, the recognition of m6A-modified RNAs mediated by IGF2BP1 was partly disturbed by circPTPRA through its interaction with KH domains of IGF2BP1. Conclusions This study identifies exonic circular circPTPRA as a new tumor suppressor that inhibits cancer progression through endogenous blocking the recognition of IGF2BP1 to m6A-modified RNAs, indicating that circPTPRA may serve as an exploitable therapeutic target for patients with BC.

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Possible role of growth regulators in adaptation to heat stress affecting partitioning of photosynthates in tomato plants

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.1989.006 ◽

2014 ◽

Vol 58 (1) ◽

pp. 71-84 ◽

Cited By ~ 6

Author(s):

Zofia Starck ◽

Elżbieta Cieśla

Keyword(s):

Heat Stress ◽

High Temperature ◽

Growth Regulators ◽

Specific Activity ◽

Invertase Activity ◽

Acid Invertase ◽

Sink Strength ◽

Tomato Plants ◽

Different Response

Tomato plants of two cultivars: Roma - sensitive and Robin - tolerant to heat stress were grown in greenhouse up to the flowering stage and then under controlled environmental conditions. The partitioning of recently fixed 14CO2 by mature tomato leaves was examined as a posteffect of 24-h heat stress (38/25°C day/night) with the interaction of growth regulators (GR) sprayed on the flowers with solution of β-naphthoxyacetic (NOA) and gibberellic (GA3) acid (denoted as NG), or Zeatin + NOA + GA3 (denoted as ZNG). In both cuitivars GR strongly stimulated fruit growth and transport of 14C-photosynthates to the clusters at the expense of vegetative organs. Heat stress decreased export of 14C-phoiosynthates from the blades in plants not treated with GR, but even more in cv. Roma. In Roma plants not treated with GR (with very small fruitlets and fruits) the heat stress retarded 14C-transport just in the petioles, diminishing the 14C-supply to the fruits. Reduction of the current photosynthate supplied to the fruits seems to be causally connected with inhibition of the specific activity of acid invertase in that organ. Growth regulators reduced the negative effect of high temperature - they alleviated depression of 14C-export from the blades and increased invertase activity. 14C-photosynthate transport to the fruits, presumably owing to their higher sink strength, was less affected by heat stress. In Robin plants (which had bigger fruits during the experiment) high temperature depressed 14C-fruit supply only in the NG-series, in contrast to enhacement of 14C-Movement to that sink in the control and ZNG-series. In spite of these facts, after heat stress, the specific activity of acid invertase decreased in all the experimental series, but much less in the GR-treated series. Therefore, in the Robin cv. there was no relation between invertase activity and 14C-mobilization by fruits, as was observed in Roma plants. The possible explanation of the different response of the two cultivars with contrasting sensitivity to heat stress; with special reference to the role of GR; diminishing injury of the plants by high temperature is discussed.

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Inheritance of heat tolerance in perennial ryegrass (Lolium perenne, Poaceae): evidence from progeny array analysis

PeerJ ◽

10.7717/peerj.11782 ◽

2021 ◽

Vol 9 ◽

pp. e11782

Author(s):

Wagdi S. Soliman ◽

Ahmed M. Abbas ◽

Stephen J. Novak ◽

Masahiro Fujimori ◽

Kazuhiro Tase ◽

...

Keyword(s):

Heat Stress ◽

Lolium Perenne ◽

Heat Tolerance ◽

Perennial Ryegrass ◽

Global Climate ◽

Wide Distribution ◽

Photosynthetic Performance ◽

Cool Season ◽

F1 Hybrid ◽

F1 Progeny

Background Heat stress is considered one of the most important environmental factors influencing plant physiology, growth, development, and reproductive output. The occurrence and damage caused by heat stress will likely increase with global climate change. Thus, there is an urgent need to better understand the genetic basis of heat tolerance, especially in cool season plants. Materials and Methods In this study, we assessed the inheritance of heat tolerance in perennial ryegrass (Lolium perenne L. subspecies perenne) , a cool season grass, through a comparison of two parental cultivars with their offspring. We crossed plants of a heat tolerant cultivar (Kangaroo Valley) with plants of a heat sensitive cultivar (Norlea), to generate 72 F1 hybrid progeny arrays. Both parents and their progeny were then exposed to heat stress for 40 days, and their photosynthetic performance (Fv/Fm values) and leaf H2O2 content were measured. Results As expected, Kangaroo Valley had significantly higher Fv/Fm values and significantly lower H2O2 concentrations than Norlea. For the F1 progeny arrays, values of Fv/Fm decreased gradually with increasing exposure to heat stress, while the content of H2O 2 increased. The progeny had a wide distribution of Fv/Fm and H 2O2 values at 40 days of heat stress. Approximately 95% of the 72 F1 progeny arrays had Fv/Fm values that were equal to or intermediate to the values of the two parental cultivars and 68% of the progeny arrays had H2O2 concentrations equal to or intermediate to their two parents. Conclusion Results of this study indicate considerable additive genetic variation for heat tolerance among the 72 progeny arrays generated from these crosses, and such diversity can be used to improve heat tolerance in perennial ryegrass cultivars. Our findings point to the benefits of combining physiological measurements within a genetic framework to assess the inheritance of heat tolerance, a complex plant response.

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