Identification and expression analysis of four light harvesting-like ( Lhc ) genes associated with light and desiccation stress in Ulva linza

2016 ◽  
Vol 478 ◽  
pp. 10-15 ◽  
Author(s):  
Zheng Guan ◽  
Shanli Mou ◽  
Xiaowen Zhang ◽  
Dong Xu ◽  
Xiao Fan ◽  
...  
2020 ◽  
Author(s):  
Teame Gereziher ◽  
Yanchao Xu ◽  
Richard Odongo Magwanga ◽  
Joy Nyangasi Kirungu ◽  
Xiaoyan Cai ◽  
...  

Abstract BackgroundCotton is an important commercial crop for its valuable source of natural fiber. Its production has undergone a sharp failure because of abiotic stress influences, of significance is drought. Moreover, plants have evolved self-defense mechanisms against the effects of several ways of abiotic factors like drought, salt, cold among others. The evolution of stress responsive transcription factors such as the trihelix, a nodule-inception-like protein (NLP), the late embryogenesis abundant (LEA) proteins among others have shown positive response in improving resistance to several forms of abiotic stress features.ResultsGenome wide identification and characterization of the effects of Light-Harvesting Chloro a/b binding (LHC) genes was carried out in cotton under drought stress conditions. A hundred and nine proteins encoded by the LHC genes were found in the cotton genome, with 55, 27, and 27 genes found to be distributed in Gossypium hirsutum, G. arboreum, and G. raimondii, respectively. The proteins encoded by the genes were unevenly distributed in various chromosomes. The Ka/Ks values were less than one, and an indication of negative selection of the gene family. differential expression arrangement of genes was showed with the majority of the genes being highly upregulated in the root tissues in relative to leave and stem tissues. Moreover, more genes were induced in M85 a relative drought tolerant germplasm.Conclusion:The results provide proof of the possible role of the LHC genes in improving drought stress tolerance, and can be explored by cotton breeders in releasing a more drought tolerant cotton germplasms.


Author(s):  
Werner Kühlbrandt ◽  
Da Neng Wang ◽  
K.H. Downing

The light-harvesting chlorophyll-a/b protein complex (LHC-II) is the most abundant membrane protein in the chloroplasts of green plants where it functions as a molecular antenna of solar energy for photosynthesis. We have grown two-dimensional (2d) crystals of the purified, detergent-solubilized LHC-II . The crystals which measured 5 to 10 μm in diameter were stabilized for electron microscopy by washing with a 0.5% solution of tannin. Electron diffraction patterns of untilted 2d crystals cooled to 130 K showed sharp spots to 3.1 Å resolution. Spot-scan images of 2d crystals were recorded at 160 K with the Berkeley microscope . Images of untilted crystals were processed, using the unbending procedure by Henderson et al . A projection map of the complex at 3.7Å resolution was generated from electron diffraction amplitudes and high-resolution phases obtained by image processing .A difference Fourier analysis with the same image phases and electron diffraction amplitudes recorded of frozen, hydrated specimens showed no significant differences in the 3.7Å projection map. Our tannin treatment therefore does not affect the structural integrity of the complex.


2019 ◽  
Vol 476 (20) ◽  
pp. 2981-3018 ◽  
Author(s):  
Petar H. Lambrev ◽  
Parveen Akhtar

Abstract The light reactions of photosynthesis are hosted and regulated by the chloroplast thylakoid membrane (TM) — the central structural component of the photosynthetic apparatus of plants and algae. The two-dimensional and three-dimensional arrangement of the lipid–protein assemblies, aka macroorganisation, and its dynamic responses to the fluctuating physiological environment, aka flexibility, are the subject of this review. An emphasis is given on the information obtainable by spectroscopic approaches, especially circular dichroism (CD). We briefly summarise the current knowledge of the composition and three-dimensional architecture of the granal TMs in plants and the supramolecular organisation of Photosystem II and light-harvesting complex II therein. We next acquaint the non-specialist reader with the fundamentals of CD spectroscopy, recent advances such as anisotropic CD, and applications for studying the structure and macroorganisation of photosynthetic complexes and membranes. Special attention is given to the structural and functional flexibility of light-harvesting complex II in vitro as revealed by CD and fluorescence spectroscopy. We give an account of the dynamic changes in membrane macroorganisation associated with the light-adaptation of the photosynthetic apparatus and the regulation of the excitation energy flow by state transitions and non-photochemical quenching.


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