scholarly journals Effects of water scarcity and salinity on the anatomy of the Tunisian table olive cultivar ‘Meski’

2021 ◽  
Vol 49 (4) ◽  
pp. 12157
Author(s):  
Dhouha SAIDANA NAIJA ◽  
Samia BEN MANSOUR GUEDDES ◽  
Mohamed BRAHAM
Keyword(s):  
Salt Stress ◽  
Drought Stress ◽  
Water Scarcity ◽  
Palisade Parenchyma ◽  
Underground Part ◽  
Olive Cultivar ◽  
Leaf Tissues ◽  
Anatomical Adaptations ◽  
Use Efficiency ◽  
Table Olive

The table olive cultivar ‘Meski’ was subjected to two stresses related to water, scarcity, and salinity. Anatomical adaptations of leaves, stems and roots were studied and compared, to value the water use efficiency of the tree. Two stress levels were adopted corresponding to moderate and severe levels. Thus, the trees behaviour was influenced by the stress type and intensity. The aerial part of the trees showed more adaptation modes than the underground part. Under both stresses, plants have fortified the protection of the leaf tissues by developing upper envelope and multiplying the trichomes. Plants reinforced the support tissues by multiplying the collenchyma and sclereids, and have amplified the transport tissues by enhancing vascularity through multiplying the number of conductive vessels. However, different behaviours seemed to be specific to each stress such an enlargement of liber and reduction of wood in the drought stress and a restriction of liber and wood tissues in salt stress. Additionally, a retraction of the palisade parenchyma and an extension of the spongy parenchyma in drought stress inversely to salt stress were noted. In the treated stems and roots, development of stomata, suber, pericyclic fiber and liber, and a restriction of wood especially in severe stress were observed. The plants developed important changes in moderate stresses; however, in the severe, the plants seemed to be stressed, by presenting no significant changes relatively to the control.

scholarly journals Identification and Expression Profiling of Nonphosphorus Glycerolipid Synthase Genes in Response to Abiotic Stresses in Dendrobium catenatum

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1204
Author(s):  
Xinqiao Zhan ◽  
Yichun Qian ◽  
Bizeng Mao
Keyword(s):  
Salt Stress ◽  
Drought Stress ◽  
Expression Profiling ◽  
Abiotic Stresses ◽  
Membrane Lipids ◽  
Chinese Herb ◽  
Growth Stages ◽  
Limited Information ◽  
Gene Structures ◽  
Functional Investigation

Dendrobium catenatum, a valuable Chinese herb, frequently experiences abiotic stresses, such as cold and drought, under natural conditions. Nonphosphorus glycerolipid synthase (NGLS) genes are closely linked to the homeostasis of membrane lipids under abiotic stress in plants. However, there is limited information on NGLS genes in D. catenatum. In this study, a total of eight DcaNGLS genes were identified from the D. catenatum genome; these included three monogalactosyldiacylglycerol synthase (DcaMGD1, 2, 3) genes, two digalactosyldiacylglycerol synthase (DcaDGD1, 2) genes, and three sulfoquinovosyldiacylglycerol synthase (DcaSQD1, 2.1, 2.2) genes. The gene structures and conserved motifs in the DcaNGLSs showed a high conservation during their evolution. Gene expression profiling showed that the DcaNGLSs were highly expressed in specific tissues and during rapid growth stages. Furthermore, most DcaNGLSs were strongly induced by freezing and post-freezing recovery. DcaMGD1 and DcaSQDs were greatly induced by salt stress in leaves, while DcaDGDs were primarily induced by salt stress in roots. Under drought stress, most DcaNGLSs were regulated by circadian rhythms, and DcaSQD2 was closely associated with drought recovery. Transcriptome analysis also revealed that MYB might be regulated by circadian rhythm and co-expressed with DcaNGLSs under drought stress. These results provide insight for the further functional investigation of NGLS and the regulation of nonphosphorus glycerolipid biosynthesis in Dendrobium.

scholarly journals Proteome Analysis of Date Palm (Phoenix dactylifera L.) under Severe Drought and Salt Stress

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Haddad A. El Rabey ◽  
Abdulrahman L. Al-Malki ◽  
Khalid O. Abulnaja
Keyword(s):  
Salt Stress ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Date Palm ◽  
Proteome Analysis ◽  
Rubisco Activase ◽  
2D Electrophoresis ◽  
Severe Drought ◽  
Protein Abundance ◽  
Low Protein

Date palm cultivars differently tolerate salinity and drought stress. This study was carried out to study the response of date palm to severe salinity and drought based on leaf proteome analysis. Eighteen-month-old date palm plants were subjected to severe salt (48 g/L NaCl) and drought (82.5 g/L PEG or no irrigation) conditions for one month. Using a protein 2D electrophoresis method, 55 protein spots were analyzed using mass spectrometry. ATP synthase CF1 alpha chains were significantly upregulated under all three stress conditions. Changes in the abundance of RubisCO activase and one of the RubisCO fragments were significant in the same spots only for salt stress and drought stress with no irrigation, and oxygen-evolving enhancer protein 2 was changed in different spots. Transketolase was significantly changed only in drought stress with PEG. The expression of salt and drought stress genes of the chosen protein spots was either overexpressed or downexpressed as revealed by the high or low protein abundance, respectively. In addition, all drought tolerance genes due to no irrigation were downregulated. In conclusion, the proteome analysis of date palm under salinity and drought conditions indicated that both salinity and drought tolerance genes were differentially expressed resulting in high or low protein abundance of the chosen protein spots as a result of exposure to drought and salinity stress condition.

scholarly journals WATER USE EFFICIENCY, GROWTH AND YIELD OF WHEAT CULTIVATED UNDER COMPETITION WITH Setaria

2015 ◽  
Vol 33 (4) ◽  
pp. 679-687 ◽  
Author(s):  
M.Z. IHSAN ◽  
F.S. EL-NAKHLAWY ◽  
S.M. ISMAIL
Keyword(s):  
Drought Stress ◽  
Water Use Efficiency ◽  
Water Use ◽  
Harvest Index ◽  
Wheat Yield ◽  
Negative Association ◽  
Growth And Yield ◽  
Yield Losses ◽  
Wheat Production ◽  
Use Efficiency

ABSTRACT Understanding the critical period of weed competition is indispensable in the development of an effective weed management program in field crops. Current experiment was planned to evaluate the critical growth period ofSetaria and level of yield losses associated with delay in weeding in rain-fed drip irrigated wheat production system of Saudi Arabia. Field experiment was conducted to evaluate the effect of weeding interval (07-21, 14-28, 21-35, 28-42 and 35-49 days after sowing) and drought stress (75% and 50% of field capacity) on Setaria growth, wheat yield and water use efficiency. Season long weedy check and wellwatered (100% FC) plots were also maintained for comparison. Weeding interval and drought stress significantly (p ≤ 0.05) affected the growth and yield of Setaria and wheat. Drought stress from 75% to 50% FC resulted in reductions of 29-40% in Setaria height, 14-27% in Setaria density and 11-26% in Setaria dry biomass. All weeding intervals except 35-49 DAS significantly suppressedSetaria growth as compared with control. Delay in weeding increased weed-crop competition interval and reduced wheat yield and yield contributors. Therefore, the lowest yield of 1836 kg ha-1 was attained for weeding interval of 35-49 DAS at 50% FC. Water use efficiency and harvest index increased with decreasing FC levels but reduced with delay in weeding. Correlation analysis predicted negative association ofSetariadensity with wheat yield and yield contributors and the highest negative association was for harvest index (-0.913) and water use efficiency (-0.614). Early management of Setaria is imperative for successful wheat production otherwise yield losses are beyond economical limits.

Adaptive responses to drought of two Retama raetam subspecies from Tunisia

2021 ◽  
Author(s):  
Ricardo GIL ◽  
Dhikra ZAYOUD ◽  
Zeineb OUERGHI ◽  
Monica BOSCAIU ◽  
Oscar VICENTE ◽  
...  
Keyword(s):  
Drought Stress ◽  
Glycine Betaine ◽  
Soluble Sugars ◽  
Co2 Concentration ◽  
Photosynthetic Parameters ◽  
Adaptive Responses ◽  
Retama Raetam ◽  
Physiological Adaptations ◽  
Use Efficiency ◽  
Desert Climate

Abstract Aims The survival and ecological distribution of plants in arid habitats are mainly conditioned by water availability and physiological adaptations to withstand drought. In the present study, we have compared the physiological responses to drought of two Retama raetam (retama) subspecies from Tunisia, one of them living under the desert climate (subsp. raetam) and the other one growing on the coast (subsp. bovei). Methods To physiologically characterize the two R. raetam subspecies, and to elucidate their main mechanisms underlying their tolerance to drought stress, parameters related to seed germination, growth, photosynthesis (net photosynthetic rate, intracellular CO2 concentration, transpiration rate, stomatal conductance and water use efficiency), and accumulation of osmolytes (proline, glycine betaine and soluble sugars) were determined in four-month-old plants subjected to stress for up to one month. Important findings Drought significantly inhibited germination, growth, and all the evaluated photosynthetic parameters. Plants of R. raetam subsp. bovei were severely affected by drought after three weeks of treatment when photosynthesis rates were up to 7-fold lower than in the controls. At the same time, proline and glycine betaine significantly accumulated compared to the irrigated controls, but much less than in R. raetam subsp. raetam; in the latter subspecies, proline and glycine betaine increased to levels 24-fold and 6-fold higher, respectively, than in the corresponding controls. In summary, the population living in the desert region exhibited stronger tolerance to drought stress than that adapted to the semiarid littoral climate, suggesting that tolerance in R. raetam is dependent on accumulation of osmolytes.

scholarly journals Soil Amendment Using Biochar and Application of K-Humate Enhance the Growth, Productivity, and Nutritional Value of Onion (Allium cepa L.) under Deficit Irrigation Conditions

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2598
Author(s):  
Khaled G. Abdelrasheed ◽  
Yasser Mazrou ◽  
Alaa El-Dein Omara ◽  
Hany S. Osman ◽  
Yasser Nehela ◽  
...  
Keyword(s):  
Drought Stress ◽  
Allium Cepa ◽  
Water Scarcity ◽  
Deficit Irrigation ◽  
Soil Amendment ◽  
Nutritional Value ◽  
Foliar Application ◽  
Field Trials ◽  
Global Challenge ◽  
Allium Cepa L

Water scarcity, due to physical shortage or inadequate access, is a major global challenge that severely affects agricultural productivity and sustainability. Deficit irrigation is a promising strategy to overcome water scarcity, particularly in arid and semiarid regions with limited freshwater resources. However, precise application of deficit irrigation requires a better understanding of the plant response to water/drought stress. In the current study, we investigated the potential impacts of biochar-based soil amendment and foliar potassium-humate application (separately or their combination) on the growth, productivity, and nutritional value of onion (Allium cepa L.) under deficient irrigation conditions in two separate field trials during the 2018/2019 and 2019/2020 seasons. Our findings showed that deficit irrigation negatively affected onion resilience to drought stress. However, these harmful effects were diminished after soil amendment using biochar, K-humate foliar application, or their combination. Briefly, integrated biochar and K-humate application increased onion growth, boosted the content of the photosynthetic pigments, enhanced the water relations, and increased the yield traits of deficient irrigation onion plants. Moreover, it improved the biochemical response, enhanced the activities of antioxidant enzymes, and enriched the nutrient value of deficiently irrigated onion plants. Collectively, these findings highlight the potential utilization of biochar and K-humate as sustainable eco-friendly strategies to improve onion resilience to deficit irrigation.

scholarly journals Silencing of The Slzf-31 Gene Decreases The Salt Stress Tolerance And Drought Tolerance Of Tomato

2021 ◽  
Author(s):  
Tong Pei ◽  
Yufang Bao ◽  
Tairu Wu ◽  
Ziyu Wang ◽  
Yue Wang ◽  
...  
Keyword(s):  
Salt Stress ◽  
Drought Stress ◽  
Virus Induced Gene Silencing ◽  
Chlorophyll Fluorescence Parameters ◽  
Tomato Plants ◽  
Drought And Salt Stress ◽  
Stem Bending ◽  
Physiological Indexes ◽  
Mda Content ◽  
Aba Content

Abstract The SlZF-31 gene is a member of the tomato C2H2 transcription factor family. Previous studies have shown that SlZF-31 gene expression is upregulated under drought stress and salt stress, but the specific function of this gene in tomato plants in response to these two kinds of stress is still unclear. To further explore the function of the SlZF-31 gene in tomato under drought stress and salt stress, we employed the virus-induced gene silencing (VIGS) method to reduce the expression of the SlZF-31 gene in tomato. The results showed that TRV2-SlZF-31 plants had higher levels of wilt and stem bending than CK and CK-TRV2 plants under drought and salt stress. The ABA content of TRV2-SlZF-31 plants were lower than those of CK and CK-TRV2 plants. The analysis of physiological indexes showed that the SOD and POD activity and the PRO content of TRV2-SlZF-31 plants were lower than those of CK and CK-TRV2 plants, while the MDA content of TRV2-SLlZF-31 plants was higher than those of CK and CK-TRV2 plants. The accumulation of H2O2 and O2- in TRV2-SlZF-31 plants was greater than those in CK and CK-TRV2 plants. The values of the chlorophyll fluorescence parameters (ΦII and qL) of TRV2-SlZF-31 plants were significantly lower than those of CK and CK-TRV2 plants. These results showed that the silencing of the SlZF-31 gene reduces the drought resistance and salt tolerance of tomato.

scholarly journals CHANGES IN FRUIT YIELD AND PHOTOSYNTHESIS PARAMETERS IN DIFFERENT OLIVE CULTIVARS (Olea europaea L.) UNDER CON-TRASTING WATER REGIMES

2020 ◽  
Vol 19 (3) ◽  
pp. 135-147
Author(s):  
Majid Golmohammadi ◽  
Omid Sofalian ◽  
Mehdi Taheri ◽  
Alireza Ghanbari ◽  
Valiollah Rasoli
Keyword(s):  
Drought Stress ◽  
Olea Europaea ◽  
Principal Component ◽  
Fruit Yield ◽  
Photosynthetic Parameters ◽  
Olive Cultivar ◽  
Drought Treatment ◽  
Olea Europaea L ◽  
Olive Cultivars ◽  
Olea Europaéa

The evergreen tree olive (Olea europaea L.) is the only species of the genus Olea that produces edible fruits with high ecological and economic value. This tree species has developed a series of physiochemical mechanisms to tolerate drought stress and grow under adverse climatic environments. One of these mechanisms is photosynthesis activities, so that as yet little information achieved about the relations between olive production and photosynthetic parameters under drought conditions. An experiment was carried out during two consecutive years (2015–2017) to study the response of 20 different olive tree cultivars (Olea europaea L.) to drought stress. Several parameters like net photosynthetic rate (PN), stomatal conductance (GS), transpiration rate (TE), photosynthetic pigments (total chlorophyll, chlorophyll a, b and carotenoid) and fruit yield were measured. The results of combined analysis of variance for fruit yield and other measured traits showed that year, drought treatment, cultivar main effects and their interactions were highly significant. The results indicated that drought stress reduced all traits, however GS (42.80%), PN (37.21%) and TE (37.17%) significantly affected by drought. Lower reduction in photosynthetic performance (PN, GS and TE) in the cultivar T7 compared to other olive cultivars allowed them to maintain better fruit yield. Principal component analysis (PCA) identified two PCs that accounted for 82.04 and 83.27% of the total variation in photosynthetic parameters under optimal and drought stress conditions, respectively. Taken together, mean comparison, relative changes due to drought and biplot analysis revealed that cultivars ‘T7’, ‘Roghani’, ‘Koroneiki’, ‘Korfolia’ and ‘Abou-satl’ displayed better response against drought stress. According to our results, one olive cultivar namely ‘T7’, could be used in olive breeding programs to improve new high yielding cultivars with drought tolerance for use in the drought-prone environments.

scholarly journals Elevated CO2 Modulates Plant Hydraulic Conductance Through Regulation of PIPs Under Progressive Soil Drying in Tomato Plants

2021 ◽  
Vol 12 ◽  
Author(s):  
Shenglan Li ◽  
Liang Fang ◽  
Josefine Nymark Hegelund ◽  
Fulai Liu
Keyword(s):  
Drought Stress ◽  
Hydraulic Conductance ◽  
Water Relation ◽  
Severe Drought ◽  
Soil Drying ◽  
Plant Water ◽  
Transcriptional Responses ◽  
Plant Water Use ◽  
Use Efficiency ◽  
Plasma Membrane Intrinsic Proteins

Increasing atmospheric CO2 concentrations accompanied by abiotic stresses challenge food production worldwide. Elevated CO2 (e[CO2]) affects plant water relations via multiple mechanisms involving abscisic acid (ABA). Here, two tomato (Solanum lycopersicum) genotypes, Ailsa Craig (AC) and its ABA-deficient mutant (flacca), were used to investigate the responses of plant hydraulic conductance to e[CO2] and drought stress. Results showed that e[CO2] decreased transpiration rate (E) increased plant water use efficiency only in AC, whereas it increased daily plant water consumption and osmotic adjustment in both genotypes. Compared to growth at ambient [CO2], AC leaf and root hydraulic conductance (Kleaf and Kroot) decreased at e[CO2], which coincided with the transcriptional regulations of genes of plasma membrane intrinsic proteins (PIPs) and OPEN STOMATA 1 (OST1), and these effects were attenuated in flacca during soil drying. Severe drought stress could override the effects of e[CO2] on plant water relation characteristics. In both genotypes, drought stress resulted in decreased E, Kleaf, and Kroot accompanied by transcriptional responses of PIPs and OST1. However, under conditions combining e[CO2] and drought, some PIPs were not responsive to drought in AC, indicating that e[CO2] might disturb ABA-mediated drought responses. These results provide some new insights into mechanisms of plant hydraulic response to drought stress in a future CO2-enriched environment.

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