scholarly journals WATER DEFICIT ENSURES THE PHOTOCHEMICAL EFFICIENCY OF Copaifera langsdorffii Desf1

2017 ◽  
Vol 41 (2) ◽  
Author(s):  
Angélica Lino Rodrigues ◽  
Liane Lima ◽  
Thayssa Rabelo Schley ◽  
Luiz Fernando Rolim de Almeida
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Photochemical Efficiency ◽  
Water Shortage ◽  
Photochemical Activity ◽  
Photochemical Quenching ◽  
High Plasticity ◽  
Effective Quantum Yield ◽  
Water Restriction ◽  
Copaifera Langsdorffii

ABSTRACT The intensity and frequency of drought periods has increased according to climate change predictions. The fast overcome and recovery are important adaptive features for plant species found in regions presenting water shortage periods. Copaifera langsdorffii is a neotropical species that has developed leaves presenting physiological mechanisms and morphological adaptations that allow its survival under seasonal water stress. We aimed in this work to observe substantial physiological responses for water saving and damage representative to the photochemical reaction after exposed plants to water stress and to subsequent recovery. We found in plants mechanisms to control water loss through the lower stomatal conductance, even after rehydration. It goes against the rapid recovery of leaves, indicated by the relative water content values restored to previously unstressed plants. Stomatal conductance was the only variable presenting high plasticity index. In photochemical activity, the species presented higher photochemical quenching, electron transport rate and effective quantum yield of photosystem II when they were subjected to rehydration after water stress period. Our results suggest that C. langsdorffii presented rapid rehydration and higher photochemical efficiency even after water restriction. These data demonstrate that this species can be used as a model for physiological studies due to the adjustment developed in response to different environmental schemes.

scholarly journals Growth, photosynthesis and leaf water potential in young plants of Copaifera langsdorffii Desf. (Caesalpiniaceae) under contrasting irradiances

2009 ◽  
Vol 21 (3) ◽  
pp. 197-208 ◽  
Author(s):  
Carlos Cesar Ronquim ◽  
Carlos Henrique B. A. Prado ◽  
João Paulo de Souza
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Photochemical Efficiency ◽  
Net Photosynthesis ◽  
Leaf Water ◽  
Total Biomass ◽  
Natural Conditions ◽  
Significant Difference ◽  
Copaifera Langsdorffii

Growth and leaf nutrient content were compared in young potted plants of Copaifera langsdorffii in sunny and shaded areas without water stress. Besides, carbon assimilation and leaf water relations were evaluated by net photosynthesis, potential photochemical efficiency and leaf water potential during daily courses in dry and rainy periods under natural conditions in both contrasting irradiances. Higher values of total biomass, height and leaf area occurred in sunny than in shaded area. On the other hand, all young plants survived in shade under natural water stress probably by reason of fast and intense biomass accumulation in favor of roots in early development. There was no significant difference about nutrient concentration in leaves between plants growing in sunny and shaded areas. Net photosynthesis in shade increased occasionally when bunches of direct light reached the leaves. Theses sunflecks took place more frequently and at high intensity in dry period but they were more effective for net photosynthesis in rainy period. The ability of young plants to persist under natural conditions in contrasting irradiance up to 1,230 days after sowing could explain the wide distribution of C. langsdorffii in Cerrado physiognomies and in different types of forest.

scholarly journals Effects of Smoke-water on Photosynthetic Characteristics of Isatis indigotica Seedlings

2012 ◽  
Vol 2 (2) ◽  
pp. 24 ◽  
Author(s):  
Jie Zhou ◽  
Lei Fang ◽  
Xiao Wang ◽  
Lanping Guo ◽  
Luqi Huang
Keyword(s):  
Water Treatment ◽  
Stomatal Conductance ◽  
Plant Growth ◽  
Photochemical Efficiency ◽  
Photosynthetic Characteristics ◽  
Photochemical Quenching ◽  
Isatis Indigotica ◽  
Photochemical Efficiency Of Psii ◽  
Non Photochemical Quenching ◽  
Smoke Water

<p>Smoke-water (SW) had been reported to improve the growth of <em>Isatis indigotica</em>, a Chinese medicinal plant. However, there were very few reports on the mechanism of smoke-water improving plant growth. In this study the effects of smoke-water on the photosynthetic characteristics of <em>I.</em><em> indigotica</em> seedlings were investigated for the purpose of understanding the mechanism behind this improved plant growth. The results showed that net photosynthetic rate (<em>P<sub>n</sub></em>) was increased by smoke-water, reaching a maximum on 15, 5 and 15 d after treatment with smoke-water at dilutions of 1:500, 1:1000 and 1:2000 respectively. Transpiration rate (<em>T<sub>r</sub></em>) and stomatal conductance (<em>G<sub>s</sub></em>) both showed similar trends to<sub> </sub><em>P<sub>n</sub></em>, however, intercellular CO<sub>2</sub> concentration<em> </em>(<em>C<sub>i</sub></em>) was decreased with smoke-water treatment. The F<sub>v</sub>/F<sub>m</sub> was not significantly influenced by smoke-water treatment. The ?PSII was markedly promoted with the application of smoke-water (1:1000) compared with the control and the coefficient of photochemical quenching (qP) showed a similar trend to ?PSII. However the coefficient of non-photochemical quenching of chlorophyll (NPQ) was decreased with treatment of smoke-water. These findings indicate that smoke-water treatment induce an increase in photosynthesis and suggest the main factors leading to this might be the improved stomatal conductance and the enhanced level of the photochemical efficiency of PSII in leaves.</p>

scholarly journals Impacts of Short-Term Water Restriction on Pelibuey Sheep: Physiological and Blood Parameters

2021 ◽  
Author(s):  
Jorge Orlay Serrano ◽  
Asiel Villares-Garachana ◽  
Nelson Correa-Herrera ◽  
Abel González-Morales ◽  
Lisbet Pérez-Bonachea ◽  
...  
Keyword(s):  
Water Stress ◽  
Short Communication ◽  
Water Shortage ◽  
Blood Parameters ◽  
Control Group ◽  
Water Restriction ◽  
Short Term ◽  
Pelibuey Sheep ◽  
Response To Water ◽  
Global Population

Abstract One of the projected effects of climate change is a reduction in rainfall in certain regions of the world. Hence, the agricultural and livestock sectors will have to cope with increasing incidences of water shortage whilst still maintaining productivity levels to feed an ever increasing global population. This short communication reports on the effect of a two week water stress on Pelibuey sheep in Cuba. Three treatments were compared viz. supply of water ad libitum; water supplied once every 3 or 6 d. Following exposure to the water stress, the results showed no changes in sheep body weight or rectal temperature. However, respiration frequency was affected with water stress causing a reduction from 23.3 to 13.3 respirations per min in control and water deprived animals, respectively. Furthermore, there was evidence for hemoconcentration in response to water stress (levels of hemoglobin increased from 9.2 to 13.1 g L-1 and hematocrits from 27.6 to 39.3% in the control group and animals restricted to water once every 6 d. The imposed water stress was also evident in the reduction of lymphocytes (from ±63 to 43%), and in increase of neutrophils (from approximately 38 to 54%) and leukocytes (from 3133 to 4933 per mm3). The results indicated a decline in the levels of antioxidants, i.e. SOD (SOD from approximately 13 to 10 U mg-1 protein and CAT activity from 23 to 9 U mg-1 protein. To the best of our knowledge, this is the first report on the response of Pelibuey sheep to short-term water shortage stress under Cuban environmental conditions.

scholarly journals Accumulation of End Products in Source Leaves Affects Photosynthetic Rate in Peach via Alteration of Stomatal Conductance and Photosynthetic Efficiency

2009 ◽  
Vol 134 (6) ◽  
pp. 667-676 ◽  
Author(s):  
Jieshan Cheng ◽  
Peige Fan ◽  
Zhenchang Liang ◽  
Yanqiu Wang ◽  
Ning Niu ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Photosystem Ii ◽  
Photosynthetic Rate ◽  
Prunus Persica ◽  
Photochemical Efficiency ◽  
Feedback Regulation ◽  
Light Period ◽  
Photochemical Quenching ◽  
Fruit Removal ◽  
End Products

In ‘Beijing 24’ peach [Prunus persica (L.) Batch] trees, a series of source leaves with differing levels of end products were created by retaining fruit (“+fruit”), removing fruit (“−fruit”), or reducing the light period. To alter the light period, leaves were covered with a bag made of brown inner paper and outer silver paper, which was then removed at different times the next day. The highest level of end products were obtained by fruit removal, while reducing the light period resulted in a lower level than “+fruit.” Net photosynthetic rate (Pn) and stomatal conductance (gs) decreased, but leaf temperatures (Tleaf) increased, following an increase in end product levels in leaves. After the “−fruit” treatment, reduced Pn was correlated with lower gs, and Tleaf increase was concomitant with decreases in maximal quantum yield of photosystem II (Fv/Fm), actual photochemical efficiency of photosystem II (ΦPSII), and photochemical quenching, and with an increase in nonphotochemical quenching. However, there were no significant differences in chlorophyll fluorescence between “+fruit” and the two treatments reducing the light period. The ΦPSII decreased following an increase in foliar sorbitol level, and it linearly decreased as sucrose and starch increased. Although fruit removal resulted in a significant accumulation of sucrose, sorbitol, and starch in leaves throughout the day, the extractable activities of several important enzymes involved in carbohydrate leaf storage and translocation did not decrease. Therefore, instead of feedback regulation by the accumulation of end products in source leaves, a high Tleaf induced by decreased stomatal aperture may play a key role in regulation of photosynthesis by limiting the photochemical efficiency of the PSII reaction centers under high levels of the end products in peach leaves.

Photosynthetic responses to chromosome doubling in relation to leaf anatomy in Lonicera japonica subjected to water stress

2009 ◽  
Vol 36 (9) ◽  
pp. 783 ◽  
Author(s):  
Wei-Dong Li ◽  
Dilip K. Biswas ◽  
Hong Xu ◽  
Chang-Qing Xu ◽  
Xian-Zhong Wang ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Water Stress ◽  
Gas Exchange ◽  
Chromosome Doubling ◽  
Starch Content ◽  
Soluble Sugars ◽  
Net Photosynthesis ◽  
Lonicera Japonica ◽  
Photochemical Quenching ◽  
Effective Quantum Yield

Gas exchange, chlorophyll fluorescence, and contents of some metabolites in two Japanese honeysuckle (Lonicera japonica Thunb.) cultivars, Damaohua (2n = 2x) and Jiufengyihao (2n = 4x), were compared with explore the function of chromosome doubling under water stress conditions. Water stress significantly decreased net photosynthesis rate, stomatal conductance, and transpiration rate of both cultivars. It also decreased electron transport rate, effective quantum yield of Photosystem II, photochemical quenching, and starch content, but increased non-photochemical quenching and contents of total soluble sugars, proline, and malondialdehyde. However, the tetraploid cultivar showed higher resistance to water stress than the diploid, as indicated by the fact that gas exchange, chlorophyll fluorescence, and metabolites were less affected for the tetraploid than the diploid. Moreover, the tetraploid recovered more quickly than the diploid after re-watering. Morphological and anatomical analysis further revealed that the tetraploid possessed less whole plant leaf area, higher leaf mass per unit area, thicker epidermis (both upper and lower) and palisade tissue, as well as denser pubescence. All of those specialised structures caused by chromosome doubling might lead to greater capacity in coping with drought stress. Our findings suggest that the effect of chromosome doubling on drought resistance in L. japonica could attribute to the improvement of structure and photosynthesis-related traits.

scholarly journals Traditional Varieties of Caupi Submitted to Water Deficit: Physiological and Biochemical Aspects

2019 ◽  
Vol 11 (6) ◽  
pp. 424
Author(s):  
Bruno do Nascimento Silva ◽  
Stelamaris de Oliveira Paula ◽  
Joniele Vieira de Oliveira ◽  
Johny de Souza Silva ◽  
Cândida Hermínia Campos de Magalhães ◽  
...  
Keyword(s):  
Water Deficit ◽  
Water Shortage ◽  
Photochemical Quenching ◽  
Family Farms ◽  
Water Restriction ◽  
High Accumulation ◽  
Brazilian Semiarid ◽  
Severe Water Deficit ◽  
Total Carbohydrates ◽  
Physiological And Biochemical

The cowpea (Vigna unguiculata (L.) Walp) it is a leguminous widely cultivated in Northeast of Brazil. In the state of Ceara, its cultivation is performed mainly by family farms who make use of traditional varieties of good adaptation to the growing region. Thus, characterizing traditional varieties with characteristics of adaptation to regions with water shortage is essential for the production of food in the world, especially in semi-arid regions. In this sense, the objective was to evaluate the physiological and biochemical responses in three genotypes of cowpea, being two traditional varieties grown in Ceara (Sempre-Verde and Cabe&ccedil;a-de-Gato) and a genotype characterized as a standard of drought tolerance (Pingo-de-Ouro-1,2) under three water regimes: irrigated, moderate deficit and severe water deficit. The parameters evaluated were: gas exchange, chlorophyll a fluorescence, photosynthetic pigments, organic solutes (proline, total carbohydrates, reducing and non-reducing carbohydrates), starch and enzyme activity (APX, G-POD, CAT and SOD). The genotype Pingo-de-Ouro-1,2 confirmed its tolerance pattern in a water deficit condition, presenting greater water potential, higher photosynthetic rate, high levels of total carbohydrates and high accumulation of proline. Among the traditional varieties, the Cabe&ccedil;a-de-Gato presented superior photosynthesis to Sempre-Verde higher Electron Transport Rate (ETR), reflecting in a greater photochemical quenching (qP) and a greater accumulation of proline, indicating that this variety presents more pronounced adaptive characteristics for water restriction conditions, which is a common condition to the Brazilian semiarid.

scholarly journals Physiological and Yield Responses of Green-Shelled Beans (Phaseolus vulgaris L.) Grown under Restricted Irrigation

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 562
Author(s):  
Karen Campos ◽  
Andrés R. Schwember ◽  
Daniel Machado ◽  
Mónica Ozores-Hampton ◽  
Pilar M. Gil
Keyword(s):  
Water Stress ◽  
Deficit Irrigation ◽  
Pot Experiment ◽  
Water Restriction ◽  
One Pot ◽  
Dry Land ◽  
Severe Water Stress ◽  
The Face ◽  
Use Efficiency ◽  
Yield Responses

Common bean is an important crop, consumed as green-shelled bean in several countries. In Chile, green-shelled beans are cultivated often as a dry land crop, vulnerable to drought. The objective of this study was to characterize the hydric and productive responses of four green-shelled bean genotypes subjected to deficit irrigation in order to outline production strategies in the face of increasing water scarcity. Two experiments were evaluated: one pot experiment with three irrigation treatments, supplying 100% of the crop evapotranspiration (ETc) (T100), 50% (T50), and 30% (T30); and an open field experiment with two treatments: 100% (I100) and 40% of ETc (I40). Treatments were applied during reproductive stage in determinate cultivars and vegetative stage in indeterminate plants. Severe water restriction (T30 and I40) in both experiments showed a significant decrease in stomatal conductances, as well as biomass and number of grains per pod; I40 treatment also showed a reduction in chlorophyll fluorescence. Water use efficiency (WUE) was higher under water stress in field (I40), but lower on the T30 treatment from the pot experiment. Determinate cultivars showed 22.7% higher of 100-seed weight compared to indeterminate type, and, thus, higher tolerance to drought. Our results indicate that severe water stress is highly harmful in terms of yield, and a moderate controlled deficit irrigation plus the use of determinate genotypes may be a strategy for producing green-shelled bean successfully under a drought scenario.

scholarly journals Exogenous melatonin improves the salt tolerance of cotton by removing active oxygen and protecting photosynthetic organs

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dan Jiang ◽  
Bin Lu ◽  
Liantao Liu ◽  
Wenjing Duan ◽  
Yanjun Meng ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Oxidative Damage ◽  
Photosynthetic Capacity ◽  
Photochemical Efficiency ◽  
Photochemical Quenching ◽  
Plant Tolerance ◽  
Signal Molecule ◽  
Ion Balance ◽  
Photosynthetic System

Abstract Background As damage to the ecological environment continues to increase amid unreasonable amounts of irrigation, soil salinization has become a major challenge to agricultural development. Melatonin (MT) is a pleiotropic signal molecule and indole hormone, which alleviates the damage of abiotic stress to plants. MT has been confirmed to eliminate reactive oxygen species (ROS) by improving the antioxidant system and reducing oxidative damage under adversity. However, the mechanism by which exogenous MT mediates salt tolerance by regulating the photosynthetic capacity and ion balance of cotton seedlings still remains unknown. In this study, the regulatory effects of MT on the photosynthetic system, osmotic modulators, chloroplast, and anatomical structure of cotton seedlings were determined under 0–500 μM MT treatments with salt stress induced by treatment with 150 mM NaCl. Results Salt stress reduces the chlorophyll content, net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, transpiration rate, PSII photochemical efficiency, PSII actual photochemical quantum yield, the apparent electron transfer efficiency, stomata opening, and biomass. In addition, it increases non-photochemical quenching. All of these responses were effectively alleviated by exogenous treatment with MT. Exogenous MT reduces oxidative damage and lipid peroxidation by reducing salt-induced ROS and protects the plasma membrane from oxidative toxicity. MT also reduces the osmotic pressure by reducing the salt-induced accumulation of Na+ and increasing the contents of K+ and proline. Exogenous MT can facilitate stomatal opening and protect the integrity of cotton chloroplast grana lamella structure and mitochondria under salt stress, protect the photosynthetic system of plants, and improve their biomass. An anatomical analysis of leaves and stems showed that MT can improve xylem and phloem and other properties and aides in the transportation of water, inorganic salts, and organic substances. Therefore, the application of MT attenuates salt-induced stress damage to plants. Treatment with exogenous MT positively increased the salt tolerance of cotton seedlings by improving their photosynthetic capacity, stomatal characteristics, ion balance, osmotic substance biosynthetic pathways, and chloroplast and anatomical structures (xylem vessels and phloem vessels). Conclusions Our study attributes help to protect the structural stability of photosynthetic organs and increase the amount of material accumulation, thereby reducing salt-induced secondary stress. The mechanisms of MT-induced plant tolerance to salt stress provide a theoretical basis for the use of MT to alleviate salt stress caused by unreasonable irrigation, fertilization, and climate change.

scholarly journals Knockout of Auxin Response Factor SlARF4 Improves Tomato Resistance to Water Deficit

2021 ◽  
Vol 22 (7) ◽  
pp. 3347
Author(s):  
Mengyi Chen ◽  
Xiaoyang Zhu ◽  
Xiaojuan Liu ◽  
Caiyu Wu ◽  
Canye Yu ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Deficit ◽  
Vascular Bundle ◽  
Plant Resistance ◽  
Quantitative Polymerase Chain Reaction ◽  
Photochemical Efficiency ◽  
Differentially Expressed ◽  
Vascular Bundles ◽  
Aba Signaling ◽  
Auxin Response

Auxin response factors (ARFs) play important roles in various plant physiological processes; however, knowledge of the exact role of ARFs in plant responses to water deficit is limited. In this study, SlARF4, a member of the ARF family, was functionally characterized under water deficit. Real-time fluorescence quantitative polymerase chain reaction (PCR) and β-glucuronidase (GUS) staining showed that water deficit and abscisic acid (ABA) treatment reduced the expression of SlARF4. SlARF4 was expressed in the vascular bundles and guard cells of tomato stomata. Loss of function of SlARF4 (arf4) by using Clustered Regularly Interspaced Short Palindromic Repeats/Cas 9 (CRISPR/Cas 9) technology enhanced plant resistance to water stress and rehydration ability. The arf4 mutant plants exhibited curly leaves and a thick stem. Malondialdehyde content was significantly lower in arf4 mutants than in wildtype plants under water stress; furthermore, arf4 mutants showed higher content of antioxidant substances, superoxide dismutase, actual photochemical efficiency of photosystem II (PSII), and catalase activities. Stomatal and vascular bundle morphology was changed in arf4 mutants. We identified 628 differentially expressed genes specifically expressed under water deficit in arf4 mutants; six of these genes, including ABA signaling pathway-related genes, were differentially expressed between the wildtype and arf4 mutants under water deficit and unlimited water supply. Auxin responsive element (AuxRE) elements were found in these genes’ promoters indicating that SlARF4 participates in ABA signaling pathways by regulating the expression of SlABI5/ABF and SCL3, thereby influencing stomatal morphology and vascular bundle development and ultimately improving plant resistance to water deficit.

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