scholarly journals Comparison of Light Condition-Dependent Differences in the Accumulation and Subcellular Localization of Glutathione in Arabidopsis and Wheat

2021 ◽  
Vol 22 (2) ◽  
pp. 607
Author(s):  
Anna Gasperl ◽  
Eszter Balogh ◽  
Ákos Boldizsár ◽  
Nadine Kemeter ◽  
Richard Pirklbauer ◽  
...  
Keyword(s):  
Light Intensity ◽  
Subcellular Distribution ◽  
Redox State ◽  
Red Light ◽  
Light Condition ◽  
Glutathione Metabolism ◽  
Transcriptional Level ◽  
Leaf Extracts ◽  
Spring Variety ◽  
Arabidopsis Mutant

This study aimed to clarify whether the light condition-dependent changes in the redox state and subcellular distribution of glutathione were similar in the dicotyledonous model plant Arabidopsis (wild-type, ascorbate- and glutathione-deficient mutants) and the monocotyledonous crop species wheat (Chinese Spring variety). With increasing light intensity, the amount of its reduced (GSH) and oxidized (GSSG) form and the GSSG/GSH ratio increased in the leaf extracts of both species including all genotypes, while far-red light increased these parameters only in wheat except for GSH in the GSH-deficient Arabidopsis mutant. Based on the expression changes of the glutathione metabolism-related genes, light intensity influences the size and redox state of the glutathione pool at the transcriptional level in wheat but not in Arabidopsis. In line with the results in leaf extracts, a similar inducing effect of both light intensity and far-red light was found on the total glutathione content at the subcellular level in wheat. In contrast to the leaf extracts, the inducing influence of light intensity on glutathione level was only found in the cell compartments of the GSH-deficient Arabidopsis mutant, and far-red light increased it in both mutants. The observed general and genotype-specific, light-dependent changes in the accumulation and subcellular distribution of glutathione participate in adjusting the redox-dependent metabolism to the actual environmental conditions.

scholarly journals The Effects of Day Length and Light Intensity on Tile Growth of Barley

1969 ◽  
Vol 22 (1) ◽  
pp. 53 ◽  
Author(s):  
D Aspinall
Keyword(s):  
Light Intensity ◽  
Linear Relationship ◽  
Light Source ◽  
Blue Light ◽  
Floral Development ◽  
Red Light ◽  
Day Length

The acceleration of flowering in barley due to the inclusion of incandescent illumination in the light source has been shown to be due to the far�red content of the light. A linear relationship between floral development and intensity of far�red light in a 16�hr photoperiod has been established with the cultivar CI5611. Barley appears to be relatively unresponsive to blue light, however.

LIGHT-STIMULATED LEAF GROWTH ON INTACT AND EXCISED BEAN PLANTS (PHASEOLUS VULGARIS L.) III. EFFECT OF LIGHT INTENSITY

1999 ◽  
Vol 47 (4) ◽  
pp. 231-236
Author(s):  
Shimon Lavee ◽  
Elizabeth Van Volkenburgh ◽  
Robert Cleland E.
Keyword(s):  
Light Intensity ◽  
Leaf Growth ◽  
Energy Requirement ◽  
Red Light ◽  
Continuous Light ◽  
Leaf Expansion ◽  
Minimal Amount ◽  
Light Intensities ◽  
Bean Plants ◽  
Effect Of Light

The effect of light intensity on primary bean leaf unfolding and elongation was studied with intact and excised 10-day-old plants grown under red light. Continuous light of 40 μmol; m−2S−1 was enough to induce maximal leaf expansion both on intact and excised bean plants. Lower light intensities had a partial effect. The growth rate during the first 24 h in light was linearly related to light intensity up to 130 μmol; m−2S−1, although this light intensity was already supra-optimal for final leaf size. The minimal amount of light energy needed for full leaf expansion was about 15 mol photons m−2. The mode of light application, level of intensity, and irradiance duration were not critical when the total energy requirement was fulfilled. Under insufficient light applications for full leaf expansion, interrupted irradiance and longer low light intensity application induced leaf elongation more efficiently. Generally, the effect of different white light intensities on primary bean leaf expansion was the same on both intact and excised red-light-grown plants.

Changes in cell size and number associated with the effects of light intensity and temperature on the leaf morphology of wheat

1970 ◽  
Vol 48 (1) ◽  
pp. 85-90 ◽  
Author(s):  
D. J. C. Friend ◽  
Marion E. Pomeroy
Keyword(s):  
Light Intensity ◽  
Cell Size ◽  
Leaf Morphology ◽  
High Light ◽  
Cell Length ◽  
Optimal Temperature ◽  
Mesophyll Cells ◽  
Cell Divisions ◽  
Spring Variety ◽  
Growth Changes

In a spring variety of wheat an increase in light intensity over the range 200 to 5000 ft-c reduced the length of the lamina by reducing both the number and length of epidermal cells. The optimal temperature for cell length was 30 °C or above, but the number of cell divisions along the lamina decreased over the range 20 to 30 °C so that lamina length was greatest at 25 °C.Similar results were obtained with a winter variety of wheat chosen to avoid complications caused by possible interference between leaf and inflorescence growth. Changes in the size of the mesophyll cells were generally similar to those in the epidermis. The thicker leaves formed at high light intensities also had thicker mesophyll cells.

scholarly journals Analysis of the light intensity dependence of the growth ofSynechocystisand of the light distribution in a photobioreactor energized by 635 nm light

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5256 ◽  
Author(s):  
Alessandro Cordara ◽  
Angela Re ◽  
Cristina Pagliano ◽  
Pascal Van Alphen ◽  
Raffaele Pirone ◽  
...  
Keyword(s):  
Light Intensity ◽  
Photosynthetic Activity ◽  
Genetic Manipulation ◽  
Incident Light ◽  
Red Light ◽  
Clear Correlation ◽  
Heterogeneous Distribution ◽  
Cultivation System ◽  
Modelling Studies ◽  
Set Up

Synechocystisgathered momentum in modelling studies and biotechnological applications owing to multiple factors like fast growth, ability to fix carbon dioxide into valuable products, and the relative ease of genetic manipulation.Synechocystisphysiology and metabolism, and consequently, the productivity ofSynechocystis-based photobioreactors (PBRs), are heavily light modulated. Here, we set up a turbidostat-controlled lab-scale cultivation system in order to study the influence of varying orange–red light intensities onSynechocystisgrowth characteristics and photosynthetic activity.Synechocystisgrowth and photosynthetic activity were found to raise as supplied light intensity increased up to 500 μmol photons m−2s−1and to enter the photoinhibition state only at 800 μmol photons m−2s−1. Interestingly, reverting the light to a non-photo-inhibiting intensity unveiledSynechocystisto be able to promptly recover. Furthermore, our characterization displayed a clear correlation between variations in growth rate and cell size, extending a phenomenon previously observed in other cyanobacteria. Further, we applied a modelling approach to simulate the effects produced by varying the incident light intensity on its local distribution within the PBR vessel. Our model simulations suggested that the photosynthetic activity ofSynechocystiscould be enhanced by finely regulating the intensity of the light incident on the PBR in order to prevent cells from experiencing light-induced stress and induce their exploitation of areas of different local light intensity formed in the vessel. In the latter case, the heterogeneous distribution of the local light intensity would allowSynechocystisfor an optimized usage of light.

scholarly journals Red-light is an environmental effector for mutualism between begomovirus and its vector whitefly

2021 ◽  
Vol 17 (1) ◽  
pp. e1008770
Author(s):  
Pingzhi Zhao ◽  
Xuan Zhang ◽  
Yuqing Gong ◽  
Duan Wang ◽  
Dongqing Xu ◽  
...  
Keyword(s):  
Plant Defenses ◽  
Red Light ◽  
Control Plant ◽  
Light Condition ◽  
Terpene Synthase ◽  
Insect Vector ◽  
Viral Pathogen ◽  
Jasmonate Signaling ◽  
Mutualistic Relationship ◽  
And Performance

Environments such as light condition influence the spread of infectious diseases by affecting insect vector behavior. However, whether and how light affects the host defense which further affects insect preference and performance, remains unclear, nor has been demonstrated how pathogens co-adapt light condition to facilitate vector transmission. We previously showed that begomoviral βC1 inhibits MYC2-mediated jasmonate signaling to establish plant-dependent mutualism with its insect vector. Here we show red-light as an environmental catalyzer to promote mutualism of whitefly-begomovirus by stabilizing βC1, which interacts with PHYTOCHROME-INTERACTING FACTORS (PIFs) transcription factors. PIFs positively control plant defenses against whitefly by directly binding to the promoter of terpene synthase genes and promoting their transcription. Moreover, PIFs interact with MYC2 to integrate light and jasmonate signaling and regulate the transcription of terpene synthase genes. However, begomovirus encoded βC1 inhibits PIFs’ and MYC2’ transcriptional activity via disturbing their dimerization, thereby impairing plant defenses against whitefly-transmitted begomoviruses. Our results thus describe how a viral pathogen hijacks host external and internal signaling to enhance the mutualistic relationship with its insect vector.

scholarly journals Plastid terminal oxidases in Chlamydomonas: connections with astaxanthin and bio-hydrogen production

2020 ◽  
Author(s):  
Hui Li ◽  
Chao Zheng ◽  
Ming Xiao ◽  
Qin Huan ◽  
Jun Chen ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Higher Plants ◽  
Light Stress ◽  
Light Condition ◽  
Protective Role ◽  
High Light ◽  
Transcriptional Level ◽  
High Light Condition ◽  
Green Microalga ◽  
Plastid Terminal Oxidase

Abstract Background: as a plasto quinol oxidase involved in plastoquinol oxidation in higher plants and microalgae, the plastid terminal oxidase (PTOX) was first recognized in the tomato mutant GHOST (GH) and Arabidopsis mutant IMMUTANS (IM). Genome sequence analysis revealed that duplication of the PTOX gene occurs in certain eukaryotic microalgae, but not in cyanobacteria and most higher plants. PTOX may also be involved in carotenoid synthesis and play a critical protective role against stress, such as high light, heat shock and hyperosmosis. However, the connections of PTOX with astaxanthin and bio-hydrogen production and their functional relationship between two PTOX genes in the model green microalga Chlamydomonas is unknown. Results: we successfully knocked down two ptoxs through RNAi in Chlamydomonas, respectively. We demonstrated that expression levels of both PTOXs were increased under stress conditions, and interestingly when one PTOX was silenced the other’s transcriptional level was significantly raised. Conclusions: this shows a complementary relationship under high light condition. In addition, the astaxanthin accumulation level was up-regulated in silenced ptox2 strain, compared to the wide type strain. What’s more, significantly increased hydrogen production was observed in silenced ptox1 strain. In conclusion, PTOXs in Chlamydomonas are connected with not only astaxanthin accumulation but also hydrogen production, and their knock-down strains provide new insights in manipulating microalgae for high light stress tolerant strains, carotenoid production and even biofuels.

scholarly journals Perkecambahan Biji Dictyoneura acuminata Blume. pada Cahaya Merah dan Merah Jauh

2016 ◽  
Vol 7 (1) ◽  
pp. 49
Author(s):  
Fitri Fatma Wardani ◽  
Dian Latifah
Keyword(s):  
Light Intensity ◽  
Papua New Guinea ◽  
Red Light ◽  
The Philippines ◽  
Ornamental Plant ◽  
Experimental Unit ◽  
East Kalimantan ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Greenhouse Control

<p>ABSTRACT</p><p><br />Dictyoneura acuminata Blume is one of species from Sapindaceae which is native to Borneo (Sabah, South Kalimantan, East Kalimantan), the Philippines, Sulawesi, Maluku and Papua New Guinea. Economically, D. acuminata is usually used as an ornamental plant because it has attractive leaves and flowers. D. acuminata propagation can be done by using seed but information on seeds and their germination is still limited. The aim of this study was to determine the pattern of<br />germination and the effect of red and far red light on D. acuminata germination. The experimental design was completely randomized design with one factor and 5 levels. The factors was light with red light, far red light, dark, greenhouse control, and laboratory controls as levels. Each level was repeated 4 times with 10 seeds in each experimental unit. Data showed that far red light causes the seeds germinate 10 days faster than seeds germinated in the greenhouse. D. acuminata seedling<br />height was affected by light. The seedling could grow higher when the light intensity decreased, a process called etiolation.</p><p>Keywords: Dictyoneura acuminata Blume, germination, light</p><p>ABSTRAK</p><p><br />Dictyoneura acuminata Blume adalah salah satu spesies dalam famili Sapindaceae yang merupakan tanaman asli Borneo (Sabah, Kalimantan Selatan, Kalimantan Timur), Filipina, Sulawesi, Maluku dan Papua Nugini. Secara ekonomi, D. acuminata biasanya dimanfaatkan sebagai tanaman hias karena memiliki daun dan bunga yang menarik. Perbanyakan D. acuminata dapat dilakukan dengan menggunakan biji tetapi informasi mengenai biji dan perkecambahannya masih terbatas. Tujuan penelitian ini ialah mengetahui pola perkecambahan dan pengaruh cahaya merah dan merah jauh terhadap perkecambahan biji D. acuminata. Rancangan percobaan yang digunakan adalah Rancangan Acak Lengkap (RAL) dengan satu faktor dan 5 taraf. Faktor yang digunakan yaitu cahaya dengan cahaya merah, cahaya merah jauh, gelap, kontrol rumah kaca, dan kontrol laboratorium sebagai tarafnya. Setiap taraf diulang sebanyak 4 kali dengan 10 biji pada setiap satuan percobaan. Hasil pengamatan menunjukkan bahwa cahaya merah jauh menyebabkan biji berkecambah lebih cepat 10 hari dibandingkan dengan biji yang dikecambahkan di rumah kaca. Tinggi kecambah D. acuminata dipengaruhi oleh perlakuan cahaya yaitu semakin sedikit intensitas cahaya semakin panjang tinggi kecambah, suatu proses yang disebut etiolasi.</p><p>Kata kunci: cahaya, Dicyoneura acuminata Blume, perkecambahan</p>

scholarly journals Effects of Light Intensity on Root Development in a D-Root Growth System

2021 ◽  
Vol 12 ◽  
Author(s):  
Yohanna Evelyn Miotto ◽  
Cibele Tesser da Costa ◽  
Remko Offringa ◽  
Jürgen Kleine-Vehn ◽  
Felipe dos Santos Maraschin
Keyword(s):  
Light Intensity ◽  
Root Growth ◽  
Root Development ◽  
Light Exposure ◽  
Light Condition ◽  
Light Response ◽  
Shoot Elongation ◽  
Growth Conditions ◽  
Auxin Signaling ◽  
Loss Of Function

Plant development is highly affected by light quality, direction, and intensity. Under natural growth conditions, shoots are directly exposed to light whereas roots develop underground shielded from direct illumination. The photomorphogenic development strongly represses shoot elongation whereas promotes root growth. Over the years, several studies helped the elucidation of signaling elements that coordinate light perception and underlying developmental outputs. Light exposure of the shoots has diverse effects on main root growth and lateral root (LR) formation. In this study, we evaluated the phenotypic root responses of wild-type Arabidopsis plants, as well as several mutants, grown in a D-Root system. We observed that sucrose and light act synergistically to promote root growth and that sucrose alone cannot overcome the light requirement for root growth. We also have shown that roots respond to the light intensity applied to the shoot by changes in primary and LR development. Loss-of-function mutants for several root light-response genes display varying phenotypes according to the light intensity to which shoots are exposed. Low light intensity strongly impaired LR development for most genotypes. Only vid-27 and pils4 mutants showed higher LR density at 40 μmol m–2 s–1 than at 80 μmol m–2 s–1 whereas yuc3 and shy2-2 presented no LR development in any light condition, reinforcing the importance of auxin signaling in light-dependent root development. Our results support the use of D-Root systems to avoid the effects of direct root illumination that might lead to artifacts and unnatural phenotypic outputs.

Sign in / Sign up

Export Citation Format

Share Document