Differential Expression of Capsicum Anthocyanin Structural Genes in Response to Temperature Stress

Anthocyanins contribute to color development in economically important vegetables, fruits and floral crops. Their expression is critical to product sensory quality attributes, potential nutritive value, and stress response. Anthocyanins are synthesized in response to numerous environmental factors including temperature and light stress and pathogen attack. We have developed several Capsicum lines, including `02C27', expressing anthocyanin pigmentation differentially in various tissues (leaf, stem, fruit and flower). HPLC analysis demonstrated that the anthocyanins within the fruit, flower and leaves of Capsicum `02C27' were identical and that the major anthocyanidin was a delphinidin glycoside. Line `02C27' exhibits anthocyanin foliar pigmentation that is accumulated differentially in response to temperature stress. Under unfavorable low temperature (20 °C day/18 °C night), mature Capsicum leaves contained 4.6 times less anthocyanin per gram fresh weight than under high (30 °C day/28 °C; day/night) temperatures. Besides containing less anthocyanin in mature leaves, young immature leaves did not develop color as quickly under the lower temperature. Utilizing cloned and sequenced gene fragments of pepper chalcone synthase (CHS), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS), we evaluated the role of transcription in regulation of flavonol biosynthesis. Analysis of anthocyanin composition and gene expression data indicated that the block in anthocyanin formation in less pigmented leaves occurred at anthocyanin synthase. In contrast to wild tupe plants, this mutant also exhibited reduced flowering and failed to set fruit under high temperature, long day conditions.

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Molecular Dynamics of Chloroplast Membranes Isolated from Wild-Type Barley and a Brassinosteroid-Deficient Mutant Acclimated to Low and High Temperatures

Biomolecules ◽

10.3390/biom11010027 ◽

2020 ◽

Vol 11 (1) ◽

pp. 27

Author(s):

Iwona Sadura ◽

Dariusz Latowski ◽

Jana Oklestkova ◽

Damian Gruszka ◽

Marek Chyc ◽

...

Keyword(s):

Molecular Dynamics ◽

Temperature Stress ◽

High Temperatures ◽

Biological Membrane ◽

Hydrophobic Core ◽

Wild Type ◽

Chloroplast Membranes ◽

Paramagnetic Resonance ◽

Photosynthetic Membranes

Plants have developed various acclimation strategies in order to counteract the negative effects of abiotic stresses (including temperature stress), and biological membranes are important elements in these strategies. Brassinosteroids (BR) are plant steroid hormones that regulate plant growth and development and modulate their reaction against many environmental stresses including temperature stress, but their role in modifying the properties of the biological membrane is poorly known. In this paper, we characterise the molecular dynamics of chloroplast membranes that had been isolated from wild-type and a BR-deficient barley mutant that had been acclimated to low and high temperatures in order to enrich the knowledge about the role of BR as regulators of the dynamics of the photosynthetic membranes. The molecular dynamics of the membranes was investigated using electron paramagnetic resonance (EPR) spectroscopy in both a hydrophilic and hydrophobic area of the membranes. The content of BR was determined, and other important membrane components that affect their molecular dynamics such as chlorophylls, carotenoids and fatty acids in these membranes were also determined. The chloroplast membranes of the BR-mutant had a higher degree of rigidification than the membranes of the wild type. In the hydrophilic area, the most visible differences were observed in plants that had been grown at 20 °C, whereas in the hydrophobic core, they were visible at both 20 and 5 °C. There were no differences in the molecular dynamics of the studied membranes in the chloroplast membranes that had been isolated from plants that had been grown at 27 °C. The role of BR in regulating the molecular dynamics of the photosynthetic membranes will be discussed against the background of an analysis of the photosynthetic pigments and fatty acid composition in the chloroplasts.

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Characteristics of educators’ talk about decontextualised events

Australasian Journal of Early Childhood ◽

10.1177/1836939120966080 ◽

2020 ◽

Vol 45 (4) ◽

pp. 362-376

Author(s):

Rebecca Andrews ◽

Penny Van Bergen

Keyword(s):

Communication Skills ◽

Future Event ◽

Time Points ◽

Long Day ◽

Future Events ◽

Day Care Centres ◽

Highly Correlated ◽

Children’S Thinking ◽

Sydney Australia

This study investigated the characteristics of educators’ talk about decontextualised events with young children in seven early childhood long day care centres in Sydney, Australia. Educators were partnered with up to six children aged between 27 and 60 months. Across two time points, 85 educator–child dyads discussed past and future events. Educators’ use of questions, contextual statements, evaluations and prompts and children’s use of questions, open-ended responses, yes-no responses and spontaneous information statements were examined. Educators’ evaluative statements were highly correlated and educators’ questions were moderately correlated with children’s open-ended responses in past event conversations. Educators’ evaluative statements were highly correlated with children’s open-ended responses in future event conversations and were the only significant predictor for children’s talk. Given the important role of educators in scaffolding children’s thinking and communication skills, the recommended strategies for educators’ talk in decontextualised conversations include: sharing the conversational load, making frequent contextual statements and following the child’s lead/interests.

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Antifreeze protein from Ammopiptanthus nanus functions in temperature-stress through domain A

Scientific Reports ◽

10.1038/s41598-021-88021-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

HaoQiang Yu ◽

HongYing Zheng ◽

Yuan Liu ◽

QingQing Yang ◽

WanChen Li ◽

...

Keyword(s):

Temperature Stress ◽

Heat Tolerance ◽

Antifreeze Protein ◽

Functional Domain ◽

E Coli ◽

Ammopiptanthus Nanus ◽

Cold Sensitive ◽

Crystal Binding ◽

Function Expression ◽

Response To Temperature

AbstractTemperature stress restricts plant growth and development. Antifreeze protein (AFP) can improve plants antifreeze ability. In our previous study, the AnAFP gene cloned from Ammopiptanthus nanus was confirmed to be an excellent candidate enhancing plant cold resistance. But, AnAFP protein shared similar structures with KnS type dehydrins including K, N and S domains except ice crystal binding domain A. Here, we generated AnAFPΔA, AnAFPΔK, AnAFPΔN and AnAFPΔS, and transformed them into ordinary and cold sensitive strains of E. coli, and Arabidopsis KS type dehydrin mutant to evaluate their function. Expression of AnAFPΔA decreases cold and heat tolerance in E. coli, meanwhile, AnAFP enhances heat tolerance in Arabidopsis, suggesting that domain A is a thermal stable functional domain. AnAFP, AnAFPΔA and AnAFPΔS localize in whole cell, but AnAFPΔK and AnAFPΔN only localizes in nucleus and cytoplasm, respectively, exhibiting that K and N domains control localization of AnAFP. Likewise, K domain blocks interaction between AnAFP and AnICE1. The result of RT-qPCR showed that expression of AnAFP, AnICE1 and AnCBF genes was significantly induced by high-temperature, indicating that the AnAFP is likely regulated by ICE1-CBF-COR signal pathway. Taken together, the study provides insights into understanding the mechanism of AnAFP in response to temperature stress and gene resource to improve heat or cold tolerance of plants in transgenic engineering.

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The role of JrPPOs in the browning of walnut explants

BMC Plant Biology ◽

10.1186/s12870-020-02768-8 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Shugang Zhao ◽

Hongxia Wang ◽

Kai Liu ◽

Linqing Li ◽

Jinbing Yang ◽

...

Keyword(s):

Tissue Culture ◽

Production Efficiency ◽

Phenolic Content ◽

Leaf Tissue ◽

Limiting Factor ◽

Mature Leaves ◽

Survival Percentage ◽

Highly Active ◽

Young Leaves

Abstract Background Tissue culture is an effective method for the rapid breeding of seedlings and improving production efficiency, but explant browning is a key limiting factor of walnut tissue culture. Specifically, the polymerization of PPO-derived quinones that cause explant browning of walnut is not well understood. This study investigated explants of ‘Zanmei’ walnut shoot apices cultured in agar (A) or vermiculite (V) media, and the survival percentage, changes in phenolic content, POD and PPO activity, and JrPPO expression in explants were studied to determine the role of PPO in the browning of walnut explants. Results The results showed that the V media greatly reduced the death rate of explants, and 89.9 and 38.7% of the explants cultured in V media and A media survived, respectively. Compared with that of explants at 0 h, the PPO of explants cultured in A was highly active throughout the culture, but activity in those cultured in V remained low. The phenolic level of explants cultured in A increased significantly at 72 h but subsequently declined, and the content in the explants cultured in V increased to a high level only at 144 h. The POD in explants cultured in V showed high activity that did not cause browning. Gene expression assays showed that the expression of JrPPO1 was downregulated in explants cultured in both A and V. However, the expression of JrPPO2 was upregulated in explants cultured in A throughout the culture and upregulated in V at 144 h. JrPPO expression analyses in different tissues showed that JrPPO1 was highly expressed in stems, young leaves, mature leaves, catkins, pistils, and hulls, and JrPPO2 was highly expressed in mature leaves and pistils. Moreover, browning assays showed that both explants in A and leaf tissue exhibited high JrPPO2 activity. Conclusion The rapid increase in phenolic content caused the browning and death of explants. V media delayed the rapid accumulation of phenolic compounds in walnut explants in the short term, which significantly decreased explants mortality. The results suggest that JrPPO2 plays a key role in the oxidation of phenols in explants after branch injury.

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Quantifying high‐temperature stress on soybean canopy photosynthesis: The unique role of sun‐induced chlorophyll fluorescence

Global Change Biology ◽

10.1111/gcb.15603 ◽

2021 ◽

Author(s):

Hyungsuk Kimm ◽

Kaiyu Guan ◽

Charles H. Burroughs ◽

Bin Peng ◽

Elizabeth A. Ainsworth ◽

...

Keyword(s):

Chlorophyll Fluorescence ◽

High Temperature ◽

Temperature Stress ◽

High Temperature Stress ◽

Canopy Photosynthesis ◽

Unique Role ◽

Soybean Canopy

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AP2/ERF and R2R3-MYB family transcription factors: potential associations between temperature stress and lipid metabolism in Auxenochlorella protothecoides

Biotechnology for Biofuels ◽

10.1186/s13068-021-01881-6 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Guanlan Xing ◽

Jinyu Li ◽

Wenli Li ◽

Sin Man Lam ◽

Hongli Yuan ◽

...

Keyword(s):

Transcription Factors ◽

Lipid Metabolism ◽

Temperature Stress ◽

Expression Profiles ◽

Critical Factor ◽

Biofuel Production ◽

Systematic Analysis ◽

Triacylglycerol Accumulation ◽

Response To Temperature ◽

R2r3 Myb

Abstract Background Both APETALA2/Ethylene Responsive Factor (AP2/ERF) superfamily and R2R3-MYB family were from one of the largest diverse families of transcription factors (TFs) in plants, and played important roles in plant development and responses to various stresses. However, no systematic analysis of these TFs had been conducted in the green algae A. protothecoides heretofore. Temperature was a critical factor affecting growth and lipid metabolism of A. protothecoides. It also remained largely unknown whether these TFs would respond to temperature stress and be involved in controlling lipid metabolism process. Results Hereby, a total of six AP2 TFs, six ERF TFs and six R2R3-MYB TFs were identified and their expression profiles were also analyzed under low-temperature (LT) and high-temperature (HT) stresses. Meanwhile, differential adjustments of lipid pathways were triggered, with enhanced triacylglycerol accumulation. A co-expression network was built between these 18 TFs and 32 lipid-metabolism-related genes, suggesting intrinsic associations between TFs and the regulatory mechanism of lipid metabolism. Conclusions This study represented an important first step towards identifying functions and roles of AP2 superfamily and R2R3-MYB family in lipid adjustments and response to temperature stress. These findings would facilitate the biotechnological development in microalgae-based biofuel production and the better understanding of photosynthetic organisms’ adaptive mechanism to temperature stress.

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Methylation of miRNA genes in the response to temperature stress in Populus simonii

Frontiers in Plant Science ◽

10.3389/fpls.2015.00921 ◽

2015 ◽

Vol 6 ◽

Cited By ~ 22

Author(s):

Dong Ci ◽

Yuepeng Song ◽

Min Tian ◽

Deqiang Zhang

Keyword(s):

Temperature Stress ◽

Populus Simonii ◽

Mirna Genes ◽

Response To Temperature

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Collaborative Cross Founder Expression Analysis (CCFEA)

10.1101/2021.03.04.422591 ◽

2021 ◽

Author(s):

Richard R Green ◽

Renee C Ireton ◽

Martin Ferris ◽

Kathleen Muenzen ◽

David R Crosslin ◽

...

Keyword(s):

Gene Expression ◽

Genetic Variation ◽

Gene Expression Data ◽

Viral Infections ◽

Collaborative Cross ◽

Visualization Tool ◽

Expression Data ◽

Individual Gene ◽

Rnaseq Data

To understand the role of genetic variation in SARS and Influenza infections we developed CCFEA, a shiny visualization tool using public RNAseq data from the collaborative cross (CC) founder strains (A/J, C57BL/6J, 129s1/SvImJ, NOD/ShILtJ, NZO/HILtJ, CAST/EiJ, PWK/PhJ, and WSB/EiJ). Individual gene expression data is displayed across founders, viral infections and days post infection.

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