scholarly journals Differential responses of ribulose-1,5-bisphosphate carboxylase/oxygenase activities of two Vigna unguiculata cultivars to salt stress

2005 ◽  
Vol 17 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Maria Erivalda Farias de Aragão ◽  
Marjorie Moreira Guedes ◽  
Maria de Lourdes Oliveira Otoch ◽  
Maria Izabel Florindo Guedes ◽  
Dirce Fernandes de Melo ◽  
...  
Keyword(s):  
Salt Stress ◽  
Chlorophyll Fluorescence ◽  
Chlorophyll Content ◽  
Vigna Unguiculata ◽  
Shoot Growth ◽  
Bisphosphate Carboxylase ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters ◽  
Root And Shoot Growth ◽  
Specific Activities

Vita 3 and Vita 5 are two Vigna unguiculata cultivars that differ in their capacities for survival in saline environments; Vita 3 is more tolerant and Vita 5 more sensitive. Both cultivars were submitted to salt stress with 0.1 M NaCl. After 8 days, root and shoot growth from both cultivars was reduced but reduction was more pronounced in Vita 5. Furthermore, leaf area was also reduced in this cultivar. Chlorophyll content and chlorophyll fluorescence parameters were not affected by salt stress, but the specific activities of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) decreased in Vita 3 and increased in Vita 5. The use of immunological techniques also revealed that the Rubisco content from Vita 3 decreased while that of Vita 5 increased. The discussion of these results is aimed at reaching a better understanding of the differences between these cultivars in relation to salt stress.

Genetic variability and identification of quantitative trait loci affecting plant growth and chlorophyll fluorescence parameters in the model legume Medicago truncatula under control and salt stress conditions

2014 ◽  
Vol 41 (9) ◽  
pp. 983 ◽  
Author(s):  
Sarah Exbrayat ◽  
Georges Bertoni ◽  
Mohamad Reza Naghavie ◽  
Ali Peyghambari ◽  
Mounavar Badri ◽  
...  
Keyword(s):  
Salt Stress ◽  
Chlorophyll Fluorescence ◽  
Quantitative Trait Loci ◽  
Genetic Variability ◽  
Plant Growth ◽  
Medicago Truncatula ◽  
Quantitative Trait ◽  
Chlorophyll Fluorescence Parameters ◽  
Model Legume ◽  
Fluorescence Parameters

Salinity is one of the major stresses that limits crop production worldwide and affects most physiological activities in plants. In order to study the genetic control of salt stress in the model legume Medicago truncatula Gaertn., an experiment was undertaken to determine the genetic variability and to identify quantitative trait loci (QTLs) controlling several traits related to plant growth and physiology in a population of recombinant inbred lines. Shoot and root DW, relative water content, leaf area, chlorophyll content, chlorophyll fluorescence parameters, and Na+ and K+ in shoots and roots were measured. The experiment was carried out with three replications. ANOVA showed a large genetic variation and transgressive segregation for the traits studied, suggesting putative complex tolerance mechanisms. A total of 21 QTLs were detected under control conditions and 19 QTLs were identified under 100 mm salt stress conditions, with three QTLs being common to both situations. The percentage of total phenotypic variance explained by the QTLs ranged from 4.6% to 23.01%. Overlapping QTLs for different traits were also observed, which enables us to discriminate independent traits from linked ones. The results should be helpful information for further functional analysis of salt tolerance in M. truncatula.

scholarly journals Gas exchange and chlorophyll fluorescence parameters in four maize genotypes influenced by first phase of salt stress

2019 ◽  
Vol 30 ◽  
pp. 26-32
Author(s):  
MN Uddin ◽  
MIU Hoque ◽  
S Monira ◽  
MAA Bari
Keyword(s):  
Salt Stress ◽  
Chlorophyll Fluorescence ◽  
Stomatal Conductance ◽  
Chlorophyll Content ◽  
Net Photosynthesis ◽  
Pure Line ◽  
Photosynthesis Rate ◽  
Chlorophyll Fluorescence Parameters ◽  
Maize Genotypes ◽  
Fluorescence Characteristics

Responses in photosynthesis, transpiration, stomatal conductance, chlorophyll fluorescence characteristics and chlorophyll content of four maize (Zea mays L.) genotypes were examined under first phase of salt stress. In the experiment four maize genotypes viz. indigenous yellow pure line, indigenous yellow, hybrid, and indigenous white were tested in two levels of salinity (control: without NaCl application; salinity: 12 dS m-1 by applying NaCl). The experiment was laid out following completely randomized design (CRD) with four replications in the net house of Department of Crop Botany, Bangladesh Agricultural University, Mymensingh. Plants were harvested on day 21 after 7 d application of full salt stress (12 dS m-1). The reductions of shoot fresh masses under salinity were 70, 57, 55 and 61% in indigenous yellow pure line, indigenous yellow, hybrid, and indigenous white, respectively. Some core physiological parameters viz. net photosynthesis rate (Pn), transpiration rate (E), stomatal conductance (gs), and the chlorophyll content decreased in all the maize genotypes except indigenous white under first phase of salt stress. In contrast, the ratio of variable fluorescence to maximal fluorescence (Fv/Fm) of photosystem II significantly decreased only in indigenous yellow pure line under salinity stress. Thus the first phase of salt stress seemed to be deleterious on its response to shoot fresh mass production in all the tested four maize genotypes with the concomitant decrease in rate of photosynthesis, rate of transpiration, stomatal conductance and chlorophyll content in all genotypes except indigenous white. Progressive Agriculture, Vol. 30, Suppl. 1: 26-32, 2019

scholarly journals Effects of sea salt stress on reflectance spectrum and chlorophyll fluorescence parameters inBambusa oldhamiileaves

2014 ◽  
Vol 34 (17) ◽  
Author(s):  
吴寿国 WU Shouguo ◽  
余学军 YU Xuejun ◽  
李凯 LI Kai ◽  
蒋玉俭 JIANG Yujian ◽  
张汝民 ZHANG Rumin
Keyword(s):  
Salt Stress ◽  
Chlorophyll Fluorescence ◽  
Reflectance Spectrum ◽  
Sea Salt ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters

scholarly journals Changes in chlorophyll fluorescence parameters during desiccation and osmotic stress of Hassallia antarctica culture

2018 ◽  
Vol 8 (2) ◽  
pp. 198-207
Author(s):  
Marta Campos Alonso
Keyword(s):  
Salt Stress ◽  
Chlorophyll Fluorescence ◽  
Osmotic Stress ◽  
Austral Summer ◽  
Rapid Decline ◽  
Filamentous Cyanobacterium ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters ◽  
Fluorescence Measurements ◽  
James Ross Island

Hassallia antarctica is a terrestrial cyanobacterium colonizing various habitats in Antarctica such as soil surface, microbiological mats and seepages. H. antarctica represents one of the cyanobacterial species forming biodiversity of terrestrial autotrophs of James Ross Island, Antarctica. It is a filamentous cyanobacterium composing blackish fasciculated clusters thanks to false branching. In our study, sensitivity of the species to dehydration and salt stress was studied. We used H. antarctica culture (CCALA 956) grown on Z liquid medium. Clusters of H. antarctica were placed on wet filter paper and dried naturally at 5°C. During gradual dehydration, relative water content (RWC) was evaluated gravimetrically simultaneously with chlorophyll fluorescence measurements. Slow Kautsky kinetics and the chlorophyll fluorescence parameters (FV/FM, ФPSII) were used to assess dehydration-related decrease in primary photosynthetic processes. It was found that H. antarctica, contrastingly to other terrestrial cyanobacteria from polar habitats, was not able to maintain photosynthetic processes at RWCs as low as 20%. Even during initial phase of dehydration (RWC of 95%) rapid decline in FV/FM occured. Resistance of H. antarctica to osmotic stress was studied by time courses of the chlorophyll fluorescence parameter in response to 3.0, 0.3, and 0.03 M NaCl solution. Both shape of slow Kautsky kinetics and numeric values of chlorophyll fluorescence parameters were affected by osmotic stress. While full inhibitory effect was apparent in 3.0 M NaCl treatment immediately, the salt stress-induced decline in chlorophyll fluorescence parameters was observed at 0.03 M NaCl even after 8 hours of exposition. It was, therefore, concluded that H. antarctica exhibited high resistance to osmotic stress which may help the species to cope with repetitive dehydration events that happen in the field during austral summer season in Antarctica, James Ross Island in particular.

scholarly journals Effects of NtSPS1 Overexpression on Solanesol Content, Plant Growth, Photosynthesis, and Metabolome of Nicotiana tabacum

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 518
Author(s):  
Ning Yan ◽  
Xiaolei Gai ◽  
Lin Xue ◽  
Yongmei Du ◽  
John Shi ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Nicotiana Tabacum ◽  
Plant Growth ◽  
Chlorophyll Content ◽  
Carbon Fixation ◽  
Leaf Growth ◽  
Pathway Enrichment Analysis ◽  
Photosynthetic Gas Exchange ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters

Nicotiana tabacum solanesyl diphosphate synthase 1 (NtSPS1) is the key enzyme in solanesol biosynthesis. However, changes in the solanesol content, plant growth, photosynthesis, and metabolome of tobacco plants after NtSPS1 overexpression (OE) have not been previously reported. In the present study, these parameters, as well as photosynthetic gas exchange, chlorophyll content, and chlorophyll fluorescence parameters, were compared between NtSPS1 OE and wild type (WT) lines of tobacco. As expected, NtSPS1 OE significantly increased solanesol content in tobacco leaves. Although NtSPS1 OE significantly increased leaf growth, photosynthesis, and chlorophyll content, the chlorophyll fluorescence parameters in the leaves of the NtSPS1 OE lines were only slightly higher than those in the WT leaves. Furthermore, NtSPS1 OE resulted in 64 differential metabolites, including 30 up-regulated and 34 down-regulated metabolites, between the OE and WT leaves. Pathway enrichment analysis of these differential metabolites identified differentially enriched pathways between the OE and WT leaves, e.g., carbon fixation in photosynthetic organisms. The maximum carboxylation rate of RuBisCO and the maximum rate of RuBP regeneration were also elevated in the NtSPS1 OE line. To our knowledge, this is the first study to confirm the role of NtSPS1 in solanesol biosynthesis and its possible functional mechanisms in tobacco.

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