Physiological and Spectral Response of the Halophyte Suaeda Salsa to Salt Stress in a Coastal Wetland Area

In order to understand the response mechanism between plant stress, physiological indicators and hyperspectral indices, pot experiments were conducted on Suaeda salsa seedlings collected from a coastal wetland area to reveal the effects of salt stress on the physiological indicators and reflectance spectra of Suaeda salsa at the canopy and leaf level. The Suaeda salsa seedlings were exposed to seven salt treatments of different concentrations (0 mmol/L (control), 50 mmol/L, 100 mmol/L, 200 mmol/L, 300 mmol/L, 400 mmol/L, and 600 mmol/L) in natural conditions. The physiological indicators of plant height, fresh weight, dry weight, leaf succulence, chlorophyll content, and carotenoid content were measured, in addition to the reflectance spectra of Suaeda salsa at both the canopy and leaf level. Firstly, the effects of salt stress on the physiological indicators and reflectance spectra were analyzed by the qualitative and quantitative methods. Then, physiological indicators sensitive to salt stress were further retrieved. Afterwards hyperspectral indices such as a/b and ((a-b)/(a+b) ) sensitive to salt stress were also extracted by one-way analysis of variance (ANOVA) and Student-Newman-Keuls (S-N-K) comparison test. Our results showed that plant height, root length, leaf succulence, biomass, Chl-a, and Chl-b were sensitive to salt stress, while carotenoids (Car) and relative water content on the root were not significantly affected by salt stress. At the salt concentration of 200 mmol/L, plant height, biomass, relative water content, leaf succulence peaked. With enhanced salt stress, physiological indicators decreased. The first-order derivative spectral reflectance has the highest correlation with salt stress, compared to the control. The spectral index most sensitive to the salt stress at the canopy level is (D903−D851)/(D903+D851), for which the multiple determination coefficient (r2) is 0.9216. While the most sensitive spectral index to the salt stress is (D442−D667)/(D442+D667) at the leaf level, for which the r2 is −0.898. In summary, the results indicated that there exists the quantitative relationship between the physiological indicators and spectra reflectance under salt stress and hyperspectral plant indices can effectively estimate the degree of salt stress. The inconsistency between the diagnostic hyperspectral plant indices at the canopy and leaf levels may be caused by the observation conditions, canopy structure.

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Salinity induced changes in water relations, oxidative damage and morpho-physiological adaptations of pistachio genotypes in soilless culture

Acta agriculturae Slovenica ◽

10.14720/aas.2017.109.2.12 ◽

2017 ◽

Vol 109 (2) ◽

pp. 291 ◽

Cited By ~ 7

Author(s):

Zahra Mirfattahi ◽

Soheil Karimi ◽

Mahmoud Reza Roozban

Keyword(s):

Salt Stress ◽

Oxidative Damage ◽

Water Relations ◽

Photosynthetic Pigments ◽

Plant Biomass ◽

Fruit Trees ◽

Salt Tolerant ◽

Cell Membrane Stability ◽

Relative Water ◽

Leaf Succulence

Selecting salt tolerant rootstocks is a sustainable approach for developing fruit trees in salinity prone areas. 60-day-old seedlings of Pistacia vera ‘Akbari’ and ‘Ghazvini’, and P. vera ‘Ghazvini’ × P. atlantica (G×A) were subjected to 0, 50, 100 and 150 mM NaCl in half strength Hoagland’s nutrient solution. After 45 days, the growth, water relations, and oxidative damage parameters were investigated. Salt stress reduced plant biomass, height, crown diameter and leaf number, but increased specific leaf area (SLA) of the seedlings. Under salt stress, the growth of ‘Akbari’ seedlings was higher than the other genotypes. Accumulation of malondialdehyde (MDA) and proline was observed in the leaves of salt affected seedlings. ‘Ghazvini’ seedlings had the highest MDA concentration and the lowest cell membrane stability in their leaves. Degredation of photosynthetic pigments under salt stress was lower in the leaves of ‘Akbari’ seedlings than that in other genotypes. Increase in leaf succulence was observed in ‘Akbari’ and G×A seedlings in response to salt stress. Relative water content and concentration of anthocyanins in the leaves of pistachio genotypes remained unchanged under salt stress. The results revealed that monitoring leaf abscission, SLA, leaf succulence, MDA concentration, and photosynthetic pigments provide suitable contrast for screening salt tolerance in pistachio. Furthuremore, ‘Akbari’ was found to be the most salt tolerant genotype.

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Increase in aquaporin activity is involved in leaf succulence of the euhalophyte Suaeda salsa, under salinity

Plant Science ◽

10.1016/j.plantsci.2008.09.019 ◽

2009 ◽

Vol 176 (2) ◽

pp. 200-205 ◽

Cited By ~ 39

Author(s):

Cui-Hua Qi ◽

Min Chen ◽

Jie Song ◽

Bao-Shan Wang

Keyword(s):

Suaeda Salsa ◽

Leaf Succulence

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Hydrogeochemistry and Water Balance in the Coastal Wetland Area of “Biviere di Gela,” Sicily, Italy

Water Air & Soil Pollution ◽

10.1007/s11270-006-9189-8 ◽

2006 ◽

Vol 178 (1-4) ◽

pp. 179-193 ◽

Cited By ~ 13

Author(s):

Emanuela Manno ◽

Massimo Vassallo ◽

Daniela Varrica ◽

Gaetano Dongarrà ◽

Sergio Hauser

Keyword(s):

Water Balance ◽

Coastal Wetland ◽

Wetland Area

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Morpho- biochemical evaluation of Brassica rapa sub-species for salt tolerance

Genetika ◽

10.2298/gensr1601323j ◽

2016 ◽

Vol 48 (1) ◽

pp. 323-338 ◽

Cited By ~ 3

Author(s):

Sohail Jan ◽

Zabta Shinwari ◽

Malik Rabbani

Keyword(s):

Salt Stress ◽

Chlorophyll A ◽

Brassica Rapa ◽

Research Work ◽

Poor Performance ◽

Dry Weight ◽

Salt Tolerant ◽

Relative Water ◽

Maximum Tolerance ◽

Yellow Type

Salt stress is one of the key abiotic stresses that affect both the qualitative and quantitative characters of many Brassica rapa sub-species by disturbing its normal morphobiochemical processes. Therefore, the present research work was designed to study the effect of different NaCl events (0, 50,100 and 150 mmol) on morphological and biochemical characters and to screen salt tolerant genotypes among brown, yellow and toria types of B. rapa sub-species. The plants were grown in test tubes with addition of four level of NaCl (0, 50,100 and 150 mmol). The effect of salinity on shoot and root length, shoot/ root fresh and dry weight, relative water content (RWC), proline and chlorophyll a, b, a+b contents was recorded after 4 weeks of sowing. The genotype 22861 (brown type) showed excellent morphological and biochemical performance at all stress levels followed by Toria-Sathi and Toria-A respectively as compared to Check variety TS-1. The genotype 26158 (yellow type) gave very poor performance and retard growth. The %RWC values and chlorophyll a, b and a+b contents were decreased several folds with the increase of salt concentration. While, the proline contents was increased with raising of salt stress. The brown and toria types showed maximum tolerance to salt stress at early germination stages as compare to yellows one. The present study will serve as model to develop quick salt tolerant genotypes among different plant sub-species against salt stress.

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Relative water content consistently predicts drought mortality risk in seedling populations with different morphology, physiology, and times to death

10.1101/2020.12.08.416917 ◽

2020 ◽

Author(s):

Gerard Sapes ◽

Anna Sala

Keyword(s):

Water Content ◽

Real Time ◽

Pinus Ponderosa ◽

Mortality Risk ◽

Relative Water Content ◽

Large Scale ◽

Water Status ◽

Physiological Indicators ◽

Relative Water ◽

Global Impacts

AbstractPredicted increases in forest drought mortality highlight the need for predictors of incipient drought-induced mortality (DIM) risk that enable proactive large-scale management. Such predictors should be consistent across plants with varying morphology and physiology. Because of their integrative nature, indicators of water status are promising candidates for real time monitoring of DIM, particularly if they standardize morphological differences among plants. We assessed the extent to which differences in morphology and physiology between Pinus ponderosa populations influence time to mortality and the predictive power of key indicators of DIM risk. Time to incipient mortality differed between populations but occurred at the same relative water content (RWC) and water potential (WP). RWC and WP were more accurate predictors of drought mortality risk than other physiological indicators, including non-structural carbohydrate (NSC) content and percent loss of conductivity (PLC). These results highlight that variables related to water status capture critical thresholds during DIM and the associated dehydration processes. Both WP and RWC are promising candidates for large-scale assessments of DIM risk. RWC is of special interest because it allows comparisons across different morphologies and can be remotely sensed. Our results offer promise for real time landscape-level monitoring of DIM and its global impacts.

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Comparison of Qinzhou bay wetland landscape information extraction by three methods

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprsarchives-xl-4-21-2014 ◽

2014 ◽

Vol XL-4 ◽

pp. 21-28 ◽

Cited By ~ 1

Author(s):

X. Chang ◽

Q. Zhang ◽

M. Luo ◽

C. Dong

Keyword(s):

Coastal Wetlands ◽

Supervised Classification ◽

Coastal Wetland ◽

Object Oriented ◽

Visual Interpretation ◽

Wetland Area ◽

The Third ◽

Tasseled Cap Transformation ◽

Qinzhou Bay ◽

Landscape Information

Wetland ecosystem plays an important role on the environment and sustainable socio-economic development. Based on the TM images in 2010 with a pretreament of Tasseled Cap transformation, three different methods are used to extract the Qinzhou Bay coastal wetlands using Supervised Classification (SC), Decision Trees (DT) and Object -oriented (OO) methods. Firstly coastal wetlands are picked out by artificial visual interpretation as discriminant standard. The result shows that when the same evaluation template used, the accuracy and Kappa coefficient of SC, DT and OO are 92.00 %, 0.8952; 89.00 %, 0.8582; 91.00 %, 0.8848 respectively. The total area of coastal wetland is 218.3 km2 by artificial visual interpretation, and the extracted wetland area of SC, DT and OO is 219 km2, 193.70 km2, 217.40 km2 respectively. The result indicates that SC is in the f irst place, followed by OO approach, and the third DT method when used to extract Qingzhou Bay coastal wetland.

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xpression of aquaporin subtypes (GhPIP1;1, GhTIP2;1, and GhSIP1;3) in cotton (Gossypium hirsutum L.) submitted to salt stress

AoB Plants ◽

10.1093/aobpla/plz072 ◽

2019 ◽

Author(s):

Luana C C Braz ◽

Pedro D Fernandes ◽

Daniela D Barbosa ◽

Wellison F Dutra ◽

Carliane R C Silva ◽

...

Keyword(s):

Salt Stress ◽

Gas Exchange ◽

Gossypium Hirsutum ◽

Water Content ◽

Relative Water Content ◽

Dry Matter ◽

Rna Extraction ◽

Gossypium Hirsutum L ◽

Relative Water ◽

Agricultural Regions

Abstract Salinization leads to several worldwide damages in agricultural regions, mainly in semiarid regions where leaching of salt is poor due to limited and erratic rainfall. Cotton (Gossypium hirsutum L.) is a Malvaceae with wide genetic variability to salt stress. The identification of salinity tolerant genotypes is a dynamic target in a breeding program, and the selection is often based on plant phenotypes. Molecular markers are reliable tools to aid in these selection procedures. Aquaporin (AQPs) are channel proteins that play fundamental role in water relations and tolerance to environmental stresses. Plants have fine regulation of water transport through AQPs activities. In order to evaluate the AQP expressions of different cotton cultivars submitted to salt stress, we use molecular and physiological tools, based on RT-qPCR and gas exchange assays. Seven cultivars were submitted to 95 mM NaCl, started at V3 stage (21 days after emergence), during 72 h. At the end of stress treatment, root tissues were used to total RNA extraction, followed by cDNA synthesis and RT-qPCR analyzes. Three sets of specific primers were used, drawn from AQP accessions deposited in NCBI. Additionally, full expanded leaves were used to gas exchange assays and to estimate the relative water content. The dry matter of the shoots was also evaluated. Based on pattern of AQPs transcripts, we found that all semiarid tolerant cultivars (BRS Seridó, 7MH, CNPA MT 2009 152 and BRS 416) showed downregulation of AQP subtypes, mainly GhPIP1;1 and GhTIP2;1 whose action is characterized as tolerant to salinity. The results of gas exchanges, relative water content and dry matter were consistent with the molecular findings in these cultivars, confirming that GhPIP1;1 and GhTIP2;1, located at plasma membrane and vacuoles, respectively, could be adopted as AQP markers for identification of cotton tolerant to salt stress.

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Effect of UV Radiation and Salt Stress on the Accumulation of Economically Relevant Secondary Metabolites in Bell Pepper Plants

Agronomy ◽

10.3390/agronomy10010142 ◽

2020 ◽

Vol 10 (1) ◽

pp. 142 ◽

Cited By ~ 3

Author(s):

Jan Ellenberger ◽

Nils Siefen ◽

Priska Krefting ◽

Jan-Bernd Schulze Lutum ◽

Daniel Pfarr ◽

...

Keyword(s):

Salt Stress ◽

Secondary Metabolites ◽

Negative Impact ◽

Stress Conditions ◽

Bell Pepper ◽

Plant Performance ◽

Production Cycle ◽

Stress Effects ◽

Leaf Level ◽

Uv Stress

The green biomass of horticultural plants contains valuable secondary metabolites (SM), which can potentially be extracted and sold. When exposed to stress, plants accumulate higher amounts of these SMs, making the extraction and commercialization even more attractive. We evaluated the potential for accumulating the flavones cynaroside and graveobioside A in leaves of two bell pepper cultivars (Mavras and Stayer) when exposed to salt stress (100 mM NaCl), UVA/B excitation (UVA 4–5 W/m2; UVB 10–14 W/m2 for 3 h per day), or a combination of both stressors. Plant age during the trials was 32–48 days. HPLC analyses proved the enhanced accumulation of both metabolites under stress conditions. Cynaroside accumulation is effectively triggered by high-UV stress, whereas graveobioside A contents increase under salt stress. Highest contents of secondary metabolites were observed in plants exposed to combined stress. Effects of stress on overall plant performance differed significantly between treatments, with least negative impact on above ground biomass found for high-UV stressed plants. The usage of two non-destructive instruments (Dualex and Multiplex) allowed us to gain insights into the ontogenetical effects at the leaf level and temporal development of SM contents. Indices provided by those devices correlate fairly with amounts detected via HPLC (Cynaroside: r2 = 0.46–0.66; Graveobioside A: r2 = 0.51–0.71). The concentrations of both metabolites tend to decrease at leaf level during the ontogenetical development even under stress conditions. High-UV stress should be considered as a tool for enriching plant leaves with valuable SM. Effects on the performance of plants throughout a complete production cycle should be evaluated in future trials. All data is available online.

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Approaching birds with drones: first experiments and ethical guidelines

Biology Letters ◽

10.1098/rsbl.2014.0754 ◽

2015 ◽

Vol 11 (2) ◽

pp. 20140754 ◽

Cited By ~ 100

Author(s):

Elisabeth Vas ◽

Amélie Lescroël ◽

Olivier Duriez ◽

Guillaume Boguszewski ◽

David Grémillet

Keyword(s):

Best Practices ◽

Unmanned Aerial Vehicles ◽

Ecological Research ◽

Ethical Guidelines ◽

Wetland Area ◽

Physiological Indicators ◽

Approach Distance ◽

Aerial Vehicles ◽

Approach Speed ◽

The Impact

Unmanned aerial vehicles, commonly called drones, are being increasingly used in ecological research, in particular to approach sensitive wildlife in inaccessible areas. Impact studies leading to recommendations for best practices are urgently needed. We tested the impact of drone colour, speed and flight angle on the behavioural responses of mallards Anas platyrhynchos in a semi-captive situation, and of wild flamingos ( Phoenicopterus roseus ) and common greenshanks ( Tringa nebularia ) in a wetland area. We performed 204 approach flights with a quadricopter drone, and during 80% of those we could approach unaffected birds to within 4 m. Approach speed, drone colour and repeated flights had no measurable impact on bird behaviour, yet they reacted more to drones approaching vertically. We recommend launching drones farther than 100 m from the birds and adjusting approach distance according to species. Our study is a first step towards a sound use of drones for wildlife research. Further studies should assess the impacts of different drones on other taxa, and monitor physiological indicators of stress in animals exposed to drones according to group sizes and reproductive status.

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