scholarly journals The photo-inhibition of camphor leaves (Cinnamomum camphora L.) by NaCl stress based on physiological, chloroplast structure and comparative proteomic analysis

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9443
Author(s):  
Jiammin Yue ◽  
Dawei Shi ◽  
Liang Zhang ◽  
Zihan Zhang ◽  
Zhiyuan Fu ◽  
...  

Background The distribution and use of camphor (Cinnamomum camphora L.) trees are constrained by increasing soil salinity in south-eastern China along the Yangtze River. However, the response mechanism of this species to salinity, especially in team of photosynthesis, are unknown. Methods Here, we analysed themorphological, physiological, ultrastructural, and proteomic traits of camphor seedlings under NaCl (103.45 mM) treatment in pot experiments for 80 days. Results The growth was limited because of photosynthetic inhibition, with the most significant disturbance occurring within 50 days. Salinity caused severe reductions in the leaf photosynthetic rate (An), stomatal conductance (gs), maximal chlorophyll fluorescence (Fm), maximum quantum yield of PSII (Fv/Fm), non-photochemical quenching (NPQ), relative quantum efficiency of PSII photochemistry (ΦPSII), photochemical quenching coefficient (qP) and photo-pigment contents (chlorophyll a (Cha), chlorophyll b (Chb), total chlorophyll (Chl)); weakened the antioxidant effects, including those of malondialdehyde (MDA), superoxide dismutase (SOD) and peroxidase (POD); and injured chloroplasts. The physiologicalresults indicated that the main reason for photo-inhibition was oxidative factors induced by NaCl. The proteomic results based on isobaric tags for relative and absolute quantitation (iTRAQ) further confirmedthat photosynthesis was the most significant disrupted process by salinity (P < 0.01) and there were 30 downregulated differentially expression proteins (DEPs) and one upregulated DEP related to restraint of the photosynthetic system, which affected photosystem I, photosystem II, the Cytochrome b6/f complex, ATP synthase and the light-harvesting chlorophyll protein complex. In addition, 57 DEPs were related to photo-inhibition by redox effect and 6 downregulated DEPs, including O2 evolving complex 33kD family protein (gi—224094610) and five other predicted proteins (gi—743921083, gi—743840443, gi—743885735, gi—743810316 and gi—743881832) were directly affected. This study provides new proteomic information and explains the possible mechanisms of photo-inhibition caused by salinity on C. camphor.


2020 ◽  
Vol 21 (7) ◽  
pp. 2496 ◽  
Author(s):  
Guizhen Lyu ◽  
Dongbing Li ◽  
Hui Xiong ◽  
Langtao Xiao ◽  
Jianhua Tong ◽  
...  

Plants use solar radiation for photosynthesis and are inevitably exposed to UV-B. To adapt to UV-B radiation, plants have evolved a sophisticated strategy, but the mechanism is not well understood. We have previously reported that STO (salt tolerance)/BBX24 is a negative regulator of UV-B-induced photomorphogenesis. However, there is limited knowledge of the regulatory network of STO in UV-B signaling. Here, we report the identification of proteins differentially expressed in the wild type (WT) and sto mutant after UV-B radiation by iTRAQ (isobaric tags for relative and absolute quantitation)-based proteomic analysis to explore differential proteins that depend on STO and UV-B signaling. A total of 8212 proteins were successfully identified, 221 of them were STO-dependent proteins in UV-B irradiated plants. The abundances of STO-dependent PSB and LHC (light-harvesting complex) proteins in sto mutants decreased under UV-B radiation, suggesting that STO is necessary to maintain the normal accumulation of photosynthetic system complex under UV-B radiation to facilitate photosynthesis photon capture. The abundance of phenylalanine lyase-1 (PAL1), chalcone synthetase (CHS), and flavonoid synthetase (FLS) increased significantly after UV-B irradiation, suggesting that the accumulation of flavonoids do not require STO, but UV-B is needed. Under UV-B radiation, STO stabilizes the structure of antenna protein complex by maintaining the accumulation of PSBs and LHCs, thereby enhancing the non-photochemical quenching (NPQ) ability, releasing extra energy, protecting photosynthesis, and ultimately promoting the elongation of hypocotyl. The accumulation of flavonoid synthesis key proteins is independent of STO under UV-B radiation. Overall, our results provide a comprehensive regulatory network of STO in UV-B signaling.



2020 ◽  
Vol 23 (7) ◽  
pp. 649-657
Author(s):  
Dong-Jiang Liao ◽  
Xi-Ping Cheng ◽  
Nan Li ◽  
Kang-Li Liang ◽  
Hui Fan ◽  
...  

Aim and Objective: Lupus nephritis (LN) is one of the major complications of systemic lupus erythematosus (SLE). The specific mechanisms of pathogenesis, aggravation, and remission processes in LN have not been clarified but is of great need in the clinic. Using isobaric tags for relative and absolute quantitation (iTRAQ) technology to screen the functional proteins of LN in mice. Especially under intervention factors of lipopolysaccharide (LPS) and dexamethasone. Methods: Mrl-lps mice were intervened with LPS, dexamethasone, and normal saline (NS) using intraperitoneal injection, and c57 mice intervened with NS as control. The anti-ANA antibody enzyme-linked immunosorbent assay (ELISA) was used to verify disease severity. Kidney tissue is collected and processed for iTRAQ to screen out functional proteins closely related to the onset and development of LN. Western blot method and rt-PCR (real-time Polymerase Chain Reaction) were used for verification. Results: We identified 136 proteins that marked quantitative information. Among them, Hp, Igkv8-27, Itgb2, Got2, and Pcx proteins showed significant abnormal manifestations. Conclusion: Using iTRAQ methods, the functional proteins Hp, Igkv8-27, Itgb2, Got2, and Pcx were screened out for a close relationship with the pathogenesis and development of LN, which is worth further study.



2002 ◽  
Vol 29 (5) ◽  
pp. 621 ◽  
Author(s):  
Salvador Nogués ◽  
Leonor Alegre

In the Mediterranean, annual mean precipitation has continuously decreased over the last three years (by ca 36% in Barcelona), and the decrease has been dramatic during the summer (by ca 78 and 64% during July and August, respectively). The impact of increased drought on the photosynthetic capacity of Mediterranean vegetation is currently unknown. In this study, two native Mediterranean plants [rosemary (Rosmarinus officinalis L.) and lavender (Lavandula stoechas L.)] were grown outdoors and subjected to two water regimes (50 mm month–1 during the summer, or no supplementary water at all). Rosemary and lavender plants watered with 50 mm month–1 during the summer had higher relative leaf water content and water potential than non-watered plants. Changes in water status were accompanied by large decreases in parameters of gas exchange [i.e. the light-saturated rate of CO2 assimilation, the maximum velocity of ribulose-1,5-bisphosphate (RuBP) carboxylation by Rubisco and the capacity for RuBP] and of modulated chlorophyll fluorescence (i.e. the relative quantum efficiency of PSII photochemistry and the efficiency of energy capture by open PSII reaction centres) during the summer, but no differences were found in any photosynthetic parameters for leaves subjected to the two water regimes. The drought-induced decreases in the relative quantum efficiency of PSII photochemistry in rosemary and lavender plants were attributable to ‘downregulation’ of electron transport. Photodamage to PSII in the field appeared to be a later effect of drought in these plants. Photorespiration was not a major mechanism protecting the photosynthetic apparatus of these plants from photodamage in the field. After the autumn rainfall, photosynthetic capacity fully recovered. We conclude that rosemary and lavender are well adapted to drought, and that an increase in water deficit is unlikely to have a significant impact on the photosynthetic capacity of leaves.



2021 ◽  
Author(s):  
Takehiro Kazama ◽  
Kazuhide Hayakawa ◽  
Takamaru Nagata ◽  
Koichi Shimotori ◽  
Akio Imai ◽  
...  

Field observations of the population dynamics and measurements of photophysiology in Lake Biwa were conducted by size class (< vs. > 30 μm) from early summer to autumn to investigate the relationships between susceptibility to light stress and cell size. Also, a nutrient bioassay was conducted to clarify whether the growth rate and photosystem II (PSII) photochemistry of small and large phytoplankton are limited by nutrient availability. Large phytoplankton, which have lower intracellular Chl-a concentrations, had higher maximum PSII photochemical efficiency (Fv/Fm) but lower non-photochemical quenching (NPQNSV) than small phytoplankton under both dark and increased light conditions. The nutrient bioassay revealed that the PSII photochemistry of small phytoplankton was restricted by N and P deficiency at the pelagic site even at the end of the stratification period, while that of large phytoplankton was not. These results suggest that large phytoplankton have lower susceptibility to PSII photodamage than small phytoplankton due to lower intracellular Chl-a concentrations. The size dependency of susceptibility to PSII photoinactivation may play a key role in large algal blooms in oligotrophic water.



Author(s):  
V. Jaldhani ◽  
D. Sanjeeva Rao ◽  
P. Beulah ◽  
B. Srikanth ◽  
P. R. Rao ◽  
...  

Aims: To assess heat-induced PSII damage and efficiency in eight promising backcross introgression lines (BC2F6) of KMR-3R/N22 possessing qHTSF1.1 and qHTSF4.1. Study Design:  Randomized Complete Block Design (RCBD) with three replications. Place and Duration of Study: ICAR-Indian Institute of Rice Research, Hyderabad India during wet/rainy (Kharif) season 2018. Methodology: Eight ILs (BC2F6) and parents were evaluated for heat tolerance. The high- temperature stress was imposed by enclosing the crop with a poly cover tent (Polyhouse) just before the anthesis stage. The fluorescence parameters viz., maximum efficiency of PSII photochemistry (Fv/Fm), Electron transport rate (ETR), effective PSII quantum yield (ΦPSII), coefficient of photochemical quenching (qP) and coefficient of non-photochemical quenching (qN) were measured under ambient and high-temperature stress. Results: The heat-tolerance potential of ILs was assessed in terms of PSII activity. The results indicated that significant differences were observed between treatments (T), genotypes (G) and the interaction between T × G.  The physiological basis of introgressed QTLs controls the spikelet fertility by maintaining the productive and adaptive strategies in heat-tolerant QTL introgressed lines with stable photosynthetic apparatus (PSII) under high-temperature stress. Conclusion: The Fv/Fm ratio denotes the maximum quantum yield of PSII. The heat-tolerant QTL introgressed lines exhibited stable photosynthetic apparatus (PSII) and noted better performance under high-temperature stress. They may be used as donors for fluorescence traits in breeding rice for high-temperature tolerance.



2014 ◽  
Vol 2 (4) ◽  
pp. 464-477
Author(s):  
Zilun Shi ◽  
Chris Dawson ◽  
Stephen L.W. On ◽  
Malik Altaf Hussain

A proteome map of the foodborne pathogen Campylobacter jejuni NCTC11168 was analyzed using a state-of-the-art gel-free proteomic approach for the first time. A whole cell protein extract was prepared from the C. jejuni strain NCTC11168 grown in brain heart infusion (BHI) broth at 42°C under microaerobic conditions. A gel-free technique using isobaric tags for relative and absolute quantitation (iTRAQ) was employed to create a protein expression profile of the strain. Liquid chromatography-mass spectrometry (LC-MS/MS) was used to identify the proteins. Protein functionalities were searched to classify them. A total of 235 proteins were identified in the whole cell protein fraction of C. jejuni NCTC11168 cells using iTRAQ analysis. Functional grouping of the identified proteins showed that forty percent of these proteins were associated with energy metabolism, protein synthesis and genetic information processing. iTRAQ was faster, easier and proved more sensitive than two-dimensional gel-based proteomics approaches previously applied to C. jejuni, making it an attractive tool for further studies of cellular physiological response. DOI: http://dx.doi.org/10.3126/ijasbt.v2i4.11253  Int J Appl Sci Biotechnol, Vol. 2(4): 464-477 



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