scholarly journals Effects of Cold Stress on the Photosynthesis and Antioxidant System of Rhododendron chrysanthum Pall.

2017 ◽  
Author(s):  
Xiaofu Zhou ◽  
Silin Chen ◽  
Hui Wu ◽  
Hongwei Xu
Keyword(s):  
Cold Stress ◽  
Antioxidant System ◽  
Molecular Mechanisms ◽  
Cold Resistance ◽  
Large Subunit ◽  
Photochemical Efficiency ◽  
Resistance Mechanisms ◽  
Photochemical Quenching ◽  
Control Group ◽  
Chlorophyll Fluorescence Parameters

Rhododendron chrysanthum Pall., live in Changbai Mountain being exposed to chilling temperature, high light intensities and water scarcity condition. To adapt to the harsh environment, the cold resistance mechanisms of R. chrysanthum have been successfully evolved in the long-term adaptive process. In our present work, the methods of proteomics combined with physiological and biochemical analyses were used to investigate the effects of cold stress on the photosynthesis and antioxidant system of Rhododendron chrysanthum Pall. and the molecular mechanisms involved in cold resistance of plants. A total of 153 photosynthesis related proteins were identified in present work, of which 7 proteins including Rubisco large subunit (rbcL) were up-regulated in experiment group (EG) compared with control group (CG). Simultaneously, four chlorophyll fluorescence parameters were measured in present study. The results showed that the maximum photochemical efficiency of photosystem II (Fv/Fm), actual quantum yield of PSII (Y(II)) and photochemical quenching (qP) were significantly higher in EG, whereas the non-photochemical quenching (NPQ) was notably decreased. Cold stress could lead to a significant reduction in electron transport rate (ETR) accompanied with an increase in excitation pressure (1-qP). The abundance of PetE which involved in the plants photosynthetic electron transfer was also significantly influenced by cold stress. Moreover, the up-regulated expressions and higher levels of enzymatic activities of Glutathione peroxidase (GPX) and Ascorbate peroxidases (APXs) were detected in EG. All these changes which can help plants to survive in low temperature are considered as the crucial parts of cold tolerance mechanisms. These results revealed that photosynthesis and redox adjustment play significant roles in the defense of cold-induced damage.

scholarly journals Phosphoproteomics of Cold Stress-Responsive Mechanisms in Rhododendron Chrysanthum

2021 ◽  
Author(s):  
yunbo liu ◽  
Ziyao Zhang ◽  
Hang Fan ◽  
Yun Tan ◽  
Xiaofu Zhou ◽  
...  
Keyword(s):  
Cold Stress ◽  
Energy Production ◽  
Molecular Mechanisms ◽  
Cold Resistance ◽  
Resistance Mechanisms ◽  
Oxygen Species ◽  
Physiological Measurement ◽  
Plant Resource ◽  
Ros Homeostasis ◽  
Cold Resistance Mechanisms

Abstract Background: As an alpine plants，Rhododendron chrysanthum (R. chrysanthum) has evolved cold resistance mechanisms and become a valuable plant resource with the responsive mechanism of cold stress. Results: In my study, we adopt the phosphoproteomic and proteomic analysis combining with physiological measurement to illustrate the responsive mechanism of R. chrysanthum seedling under cold (4℃) stress. After chilling for 12 h, 350 significantly changed proteins and 274 significantly changed phosphoproteins were detected. COG analysis showed that significantly changed proteins and phosphoproteins were mainly involved in signal transduction and energy production and conversion under cold stress. The results indicated photosynthesis was inhibited under cold stress, but cold induced calcium-mediated signaling, reactive oxygen species (ROS) homeostasis and other transcription regulation factors could protect plants from destruction caused by cold stress. Conclusions: These data constitute a cold stress-responsive metabolic atlas in R. chrysanthum, which will springboard further investigations into the complex molecular mechanisms of plant cold adaptation.

scholarly journals Effects of Different Shading Rates on the Photosynthesis and Corm Weight of Konjac Plant

2019 ◽  
Vol 47 (3) ◽  
Author(s):  
Yaoguo QIN ◽  
Zesheng YAN ◽  
Honghui GU ◽  
Zhengxiang WANG ◽  
Xiong JIANG ◽  
...  
Keyword(s):  
Photosynthetic Efficiency ◽  
Daily Variation ◽  
Photochemical Efficiency ◽  
High Yield ◽  
Photochemical Quenching ◽  
Digital Object Identifier ◽  
Chlorophyll Fluorescence Parameters ◽  
Relative Electron ◽  
Comprehensive Comparison ◽  
Non Photochemical Quenching

To study the effects of shading level on the photosynthesis and corm weight of konjac plant, the chlorophyll fluorescence parameters, daily variation of relative electron transport rate (rETR), net photosynthetic rate (Pn), and corm weight of konjac plants under different treatments were measured and comparatively analyzed through covered cultivation of biennial seed corms with shade nets at different shading rates (0%, 50%, 70%, and 90%). The results showed that with the increase in shading rate, the maximum photochemical efficiency, potential activity, and non-photochemical quenching of photosystem Ⅱ (PSⅡ) of konjac leaves constantly increased, whereas the actual photosynthetic efficiency, rETR, and photochemical quenching of PSⅡ initially increased and then decreased. This result indicated that moderate shading could enhance the photosynthetic efficiency of konjac leaves. The daily variation of rETR in konjac plants under unshaded treatment showed a bimodal curve, whereas that under shaded treatment displayed a unimodal curve. The rETR of plants with 50% treatment and 70% treatment was gradually higher than that under unshaded treatment around noon. The moderate shading could increase the Pn of konjac leaves. The stomatal conductance and transpiration rate of the leaves under shaded treatment were significantly higher than those of the leaves under unshaded treatment. Shading could promote the growth of plants and increase corm weight. The comprehensive comparison shows that the konjac plants had strong photosynthetic capacity and high yield when the shading rate was 50%-70% for the area.   ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 3, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********

scholarly journals Physiological and transcriptome analysis of Poa pratensis var. anceps cv. Qinghai in response to cold stress

2020 ◽  
Author(s):  
Wenke Dong ◽  
Xiang Ma ◽  
Hanyu Jiang ◽  
Chunxu Zhao ◽  
Huiling Ma
Keyword(s):  
Low Temperature ◽  
Cold Stress ◽  
Molecular Mechanisms ◽  
Cold Resistance ◽  
Poa Pratensis ◽  
Tca Cycle ◽  
Sucrose Metabolism ◽  
Tibet Plateau ◽  
Glutathione Metabolism ◽  
Cold Response

Abstract Background Low temperature limits the growth and geographical distribution of plants. Poa pratensis is a cool-season turfgrass mainly grown in urban areas. However, low winter temperature or cold events in spring and autumn may cause P.pratensis mortality, affecting the appearance of lawns. P.pratensis var. anceps cv. Qinghai (PQ) is widely distributed in the Qinghai-Tibet Plateau above 3000 m. PQ has greater cold resistance than the commercially cultivated P.pratensis varieties. However, existing studies on the response mechanism of PQ to low temperatures have mainly focused on physiological and biochemical perspectives, while changes in the PQ transcriptome during the response to cold stress have not been reported. Results To investigate the molecular mechanism of the PQ cold response and identify genes to improve the low-temperature resistance of P.pratensis, we analyzed and compared the transcriptomes of PQ and the cold-sensitive P.pratensis cv. ‘Baron’ (PB) under cold stress using RNA sequencing. We identified 4878 and 1871 differentially expressed genes (DEGs) between the treatment vs control comparison of PQ and PB, respectively, with 4494 DEGs specific to PQ. Based on the DEGs, important Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, such as “starch and sucrose metabolism”, “protein processing in endoplasmic reticulum”, “phenylalanine metabolism” and “glycolysis/gluconeogenesis” were significantly enriched in PQ, and “starch and sucrose metabolism”, “phenylpropanoid biosynthesis”, “galactose metabolism” and “glutathione metabolism” were significantly enriched in PB. In addition, the “glycolysis” and “citrate cycle (TCA cycle)” pathways were identified as involved in cold resistance of P.pratensis. Conclusions As we know, this is the first study to explore the transcriptome of P.pratensis var. anceps cv. Qinghai. Our study not noly provides important insights into the molecular mechanisms of P.pratensis var. anceps cv. Qinghai responds to cold stress, but also systematically reveals the changes of key genes and products of glycolysis and TCA cycle in response to cold stress, which is conductive to the breeding of cold-resistant P.pratensis genotype.

Promoting pepper (Capsicum annuum) photosynthesis via chloroplast ultrastructure and enzyme activities by optimising the ammonium to nitrate ratio

2020 ◽  
Vol 47 (4) ◽  
pp. 303
Author(s):  
Jing Zhang ◽  
Jianming Xie ◽  
Yantai Gan ◽  
Jeffrey A. Coulter ◽  
Mohammed Mujitaba Dawuda ◽  
...  
Keyword(s):  
Plant Growth ◽  
Capsicum Annuum ◽  
Photosynthetic Rate ◽  
Large Subunit ◽  
Photochemical Efficiency ◽  
Chloroplast Ultrastructure ◽  
Photochemical Quenching ◽  
Gas Exchange Parameters ◽  
Chilli Pepper ◽  
N Assimilation

Optimal plant growth in many species is achieved when the two major forms of N are supplied at a particular ratio. In this pot experiment, the effects of five different ammonium:nitrate ratios (ANRs) (0:100, 12.5:87.5, 25:75, 37.5:62.5, and 50:50) on photosynthesis efficiency in chilli pepper (Capsicum annuum L.) plants were evaluated. The results showed that an ANR of 25:75 increased the contents of chl a, leaf area and dry matter, whereas chl b content was not affected by the ANRs. Regarding chlorophyll fluorescence, an ANR of 25:75 also enhanced the actual photochemical efficiency, photochemical quenching and maximum photosynthetic rate. However, the 0:100 and 50:50 ANRs resulted in higher values for nonphotochemical quenching. An inhibition of maximal photochemical efficiency was found when 50% NH4+ was supplied at the later stage of plant growth. The addition of 25% or 37.5% NH4+ was beneficial for gas exchange parameters and the 25% NH4+ optimised the thylakoid of chloroplasts. Compared with nitrate alone, 12.5–50% NH4+ upregulated glutamate dehydrogenase (GDH), the large subunit and the small subunit of Rubisco. It can be concluded that the 25:75 ANR accelerated N assimilation through active GDH, which provides a material basis for chloroplast and Rubisco formation, resulting in the increased photosynthetic rate and enhanced growth in chilli pepper.

scholarly journals Physiological Responses and Proteomic Analysis on the Cold Stress Responses of Annual Pitaya (Hylocereus spp.) Branches

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Junliang Zhou ◽  
Lijuan Wang ◽  
Tujian Xiao ◽  
Zhuang Wang ◽  
Yongya Mao ◽  
...  
Keyword(s):  
Cold Stress ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Cold Resistance ◽  
Physiological Responses ◽  
Soluble Sugar ◽  
Multivariate Statistical ◽  
Chlorophyll Contents ◽  
Proteomic Approach ◽  
Related Proteins

In this study, the physiological response of the annual branches of three varieties of pitaya (Xianmi, Fulong, and Zihonglong) in cold stress was investigated using a multivariate statistical method. Physiological change results showed that cold stress could decrease the moisture and chlorophyll contents, on the contrary, increase the relative electric conductivity, the contents of malonadehyde, soluble protein, soluble sugar, and free proline, and enhance the enzyme activities of peroxidase, superoxide dismutase, and catalase. Meanwhile, a comparative proteomic approach was also conducted to clarify the cold resistance-related proteins and pathways in annual pitaya branches. Proteomics results concluded that the cold tolerance of annual pitaya branches could be improved by modulating autophagy. Therefore, we hypothesized that an increased autophagy ability may be an important characteristic of the annual pitaya branches in response to cold stress conditions. Our results provide a good understanding of the physiological responses and molecular mechanisms of the annual pitaya branches in response to cold stress.

scholarly journals Transcriptome analysis of the Larimichthys polyactis under heat and cold stress

2019 ◽  
Author(s):  
Tianqi Chu ◽  
Feng Liu ◽  
Gaochan Qin ◽  
Wei Zhan ◽  
Mengjie Wang ◽  
...  
Keyword(s):  
Cold Stress ◽  
Temperature Stress ◽  
Large Scale ◽  
Molecular Mechanisms ◽  
Control Group ◽  
Pathway Enrichment Analysis ◽  
Larimichthys Polyactis ◽  
Small Yellow Croaker ◽  
Heat And Cold Stress ◽  
Temperature Group

AbstractThe small yellow croaker (Larimichthys polyactis) is an important marine economic fish that is widely distributed in the East Sea, Yellow Sea and Bohai of China. However, the wild populations of small yellow croaker are severely depleted, and there is currently a developing large-scale artificial propagation of this fish for aquaculture. However, the current variety of small yellow croaker that is cultivated is not capable to coping with large fluctuations in temperature. Therefore, it is important to understand the molecular mechanisms that are activated in response to temperature stress in the small yellow croaker. Here, we conducted transcriptomic analysis of the liver of small yellow croaker under heat and cold stress. A total of 270,844,888, 265,727,006 and 259,666,218 clean reads were generated from heat temperature group, low temperature group and control group, respectively, and comparing expression of genes in these transcriptomes,10,878 unigenes that were differential expressed were identified. Sixteen of the differentially expressed unigenes were validated by qRT-PCR. Pathway enrichment analysis identified that the ER pathway, immune signaling pathway and metabolic response pathway were affected by temperature stress. The results of this study provide a comprehensive overview of temperature stress-induced transcriptional patterns in liver tissues of the small yellow croaker. In addition, these results can guide future molecular studies of heat and cold stress response in this species for improving the stock used for aquaculture.

Corrigendum to: Promoting pepper (Capsicum annuum) photosynthesis via chloroplast ultrastructure and enzyme activities by optimising the ammonium to nitrate ratio

2020 ◽  
Vol 47 (5) ◽  
pp. 473
Author(s):  
Jing Zhang ◽  
Jianming Xie ◽  
Yantai Gan ◽  
Jeffrey A. Coulter ◽  
Mohammed Mujitaba Dawuda ◽  
...  
Keyword(s):  
Plant Growth ◽  
Capsicum Annuum ◽  
Photosynthetic Rate ◽  
Large Subunit ◽  
Photochemical Efficiency ◽  
Chloroplast Ultrastructure ◽  
Photochemical Quenching ◽  
Gas Exchange Parameters ◽  
Chilli Pepper ◽  
N Assimilation

Optimal plant growth in many species is achieved when the two major forms of N are supplied at a particular ratio. In this pot experiment, the effects of five different ammonium:nitrate ratios (ANRs) (0:100, 12.5:87.5, 25:75, 37.5:62.5, and 50:50) on photosynthesis efficiency in chilli pepper (Capsicum annuum L.) plants were evaluated. The results showed that an ANR of 25:75 increased the contents of chl a, leaf area and dry matter, whereas chl b content was not affected by the ANRs. Regarding chlorophyll fluorescence, an ANR of 25:75 also enhanced the actual photochemical efficiency, photochemical quenching and maximum photosynthetic rate. However, the 0:100 and 50:50 ANRs resulted in higher values for nonphotochemical quenching. An inhibition of maximal photochemical efficiency was found when 50% NH4+ was supplied at the later stage of plant growth. The addition of 25% or 37.5% NH4+ was beneficial for gas exchange parameters and the 25% NH4+ optimised the thylakoid of chloroplasts. Compared with nitrate alone, 12.5–50% NH4+ upregulated glutamate dehydrogenase (GDH), the large subunit and the small subunit of Rubisco. It can be concluded that the 25:75 ANR accelerated N assimilation through active GDH, which provides a material basis for chloroplast and Rubisco formation, resulting in the increased photosynthetic rate and enhanced growth in chilli pepper.

scholarly journals Characterization of Biological Pathways Regulating Acute Cold Resistance of Zebrafish

2021 ◽  
Vol 22 (6) ◽  
pp. 3028
Author(s):  
Jing Ren ◽  
Yong Long ◽  
Ran Liu ◽  
Guili Song ◽  
Qing Li ◽  
...  
Keyword(s):  
Cold Stress ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Cold Resistance ◽  
Biological Pathways ◽  
Mitogen Activated Protein Kinase ◽  
Rna Seq ◽  
Zebrafish Larvae ◽  
P53 Signaling ◽  
Mitogen Activated Protein

Low temperature stress represents a major threat to the lives of both farmed and wild fish species. However, biological pathways determining the development of cold resistance in fish remain largely unknown. Zebrafish larvae at 96 hpf were exposed to lethal cold stress (10 °C) for different time periods to evaluate the adverse effects at organism, tissue and cell levels. Time series RNA sequencing (RNA-seq) experiments were performed to delineate the transcriptomic landscape of zebrafish larvae under cold stress and during the subsequent rewarming phase. The genes regulated by cold stress were characterized by progressively enhanced or decreased expression, whereas the genes associated with rewarming were characterized by rapid upregulation upon return to normal temperature (28 °C). Genes such as trib3, dusp5 and otud1 were identified as the representative molecular markers of cold-induced damages through network analysis. Biological pathways involved in cold stress responses were mined from the transcriptomic data and their functions in regulating cold resistance were validated using specific inhibitors. The autophagy, FoxO and MAPK (mitogen-activated protein kinase) signaling pathways were revealed to be survival pathways for enhancing cold resistance, while apoptosis and necroptosis were the death pathways responsible for cold-induced mortality. Functional mechanisms of the survival-enhancing factors Foxo1, ERK (extracellular signal-regulated kinase) and p38 MAPK were further characterized by inhibiting their activities upon cold stress and analyzing gene expression though RNA-seq. These factors were demonstrated to determine the cold resistance of zebrafish through regulating apoptosis and p53 signaling pathway. These findings have provided novel insights into the stress responses elicited by lethal cold and shed new light on the molecular mechanisms underlying cold resistance of fish.

scholarly journals Transcriptome and physiological analysis of increase in drought stress tolerance by melatonin in tomato

2021 ◽  
Author(s):  
Lu Yang ◽  
Sijia Bu ◽  
Shengxue Zhao ◽  
Ning Wang ◽  
Jiaxin Xiao ◽  
...  
Keyword(s):  
Drought Stress ◽  
Molecular Mechanisms ◽  
Maximum Efficiency ◽  
Photochemical Quenching ◽  
Physiological Parameter ◽  
Effective Quantum Yield ◽  
Melatonin Treatment ◽  
Tomato Cultivar ◽  
Chlorophyll Fluorescence Parameters ◽  
Psii Photochemistry

Abstract Drought stress seriously affects tomato growth, yield and quality. Previous reports have pointed out that melatonin (MT) can alleviate drought stress damage to tomato. To better understand the possible physiological and molecular mechanisms, chlorophyll fluorescence parameters and leaf transcriptome profiles were analyzed in the “Micro Tom” tomato cultivar with or without melatonin irrigation under normal and drought conditions. Polyethylene glycol 6000 (PEG6000) simulated continuous drought treatment reduced plant height, but melatonin treatment improved plant growth rate. Physiological parameter measurements revealed that the drought-induced decreases in maximum efficiency of photosystem II (PSII) photochemistry, the effective quantum yield of PSII, electron transfer rate, and photochemical quenching value caused by PEG6000 treatment were alleviated by melatonin treatment, which suggests a protective effect of melatonin on PSII. Comparative transcriptome analysis identified 447, 3982, 4526 and 3258 differentially expressed genes (DEGs) in the comparative groups plus-melatonin vs. minus-melatonin (no drought), drought vs. no drought (minus-melatonin), drought vs. no drought (melatonin) and plus-melatonin vs. minus-melatonin (drought), respectively. Furthermore, 101 DEGs were common to these four comparative groups. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis revealed that DEGs in the four comparative groups were involved in multiple metabolic processes and closely related to hormone signal transduction and transcription factors. These results provide new insights into a probable mechanism of the melatonin-induced protection of photosynthesis and enhancement of drought tolerance in tomato plants.

scholarly journals Effects of the red:far-red light ratio on photosynthetic characteristics of greenhouse cut Chrysanthemum – Short communication

2013 ◽  
Vol 40 (No. 1) ◽  
pp. 40-43 ◽  
Author(s):  
Z.Q. Yang ◽  
Y.X Li ◽  
J.B. Zhang ◽  
J. Zhang ◽  
J. Zhu ◽  
...  
Keyword(s):  
Photosynthetic Rate ◽  
Red Light ◽  
Photochemical Efficiency ◽  
Photosynthetic Characteristics ◽  
Photochemical Quenching ◽  
Light Sources ◽  
Chlorophyll Fluorescence Parameters ◽  
Spad Value ◽  
Red Led ◽  
R:Fr Ratio

For the use of LED as a light source to regulate the photosynthesis of chrysanthemum leaves under greenhouse conditions, the effects of different red (660 &plusmn; 30 nm) to far-red (730 &plusmn; 30 nm) radiation ratios (R:FR) on the photosynthetic characteristics and chlorophyll fluorescence parameters of chrysanthemum leaves were studied. Red and far-red LED light sources were combined in different proportions to produce four R:FR ratio treatments: 0.5, 2.5, 4.5 and 6.5. The chlorophyll a content, SPAD value, net photosynthetic rate, light-saturated maximum photosynthetic rate, CO<sub>2</sub>-saturated carboxylation rate, apparent quantum efficiency and carboxylation efficiency were all the highest under the R:FR ratio of 2.5, followed by the R:FR ratio of 4.5. Potential photochemical efficiency of photosystem II, photochemical quenching and electron transport rate for the R:FR ratios of 2.5 and 4.5 were markedly higher than those for 0.5 and 6.5, however, those parameters did not differ significantly between the R:FR ratios of 2.5 and 4.5.

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