scholarly journals The shift from plant-plant facilitation to competition under severe water deficit is spatially explicit

2017 ◽  
Vol 7 (7) ◽  
pp. 2441-2448 ◽  
Author(s):  
Michael J. O'Brien ◽  
Francisco I. Pugnaire ◽  
Cristina Armas ◽  
Susana Rodríguez-Echeverría ◽  
Christian Schöb
Keyword(s):  
Water Deficit ◽  
Spatially Explicit ◽  
Severe Water Deficit ◽  
Plant Facilitation ◽  
Plant Plant

Defence mechanisms against production of free radicals in cells of ‘resurrection’ plants

1994 ◽  
Vol 102 ◽  
pp. 291-294
Author(s):  
Cristina L. M. Sgherri ◽  
Mike F. Quartacci ◽  
Adriana Bochicchio ◽  
Flavia Navari-Izzo
Keyword(s):  
Free Radicals ◽  
Water Deficit ◽  
Water Loss ◽  
Physiological Activity ◽  
Physiological State ◽  
Resurrection Plant ◽  
Resurrection Plants ◽  
Defence Mechanisms ◽  
Adaptation Mechanism ◽  
Severe Water Deficit

The ability of protoplasm to revive following severe water deficit is at its greatest in desiccation-tolerant or ‘resurrection’ plants. Boea hygroscopica is a resurrection plant that is able to survive air-dryness following slow dehydration (80% RH) in a physiological state called anabiosis (Schwab & Gaff 1990). However, this plant loses the ability to recover complete physiological activity following rapid water loss (0% RH).The ability to recover complete physiological activity following repeated protoplasmic dehydration of fully differentiated tissues is an adaptation mechanism unique to resurrection plants.

Anatomical adaptations of the desert species Stipa lagascae against drought stress

Biologia ◽  
2015 ◽  
Vol 70 (8) ◽  
Author(s):  
Façal Boughalleb ◽  
Raoudha Abdellaoui ◽  
Zied Hadded ◽  
Mohammed Neffati
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Water Deficit ◽  
Cortical Cell ◽  
Severe Drought ◽  
Leaf Rolling ◽  
Drought Period ◽  
Severe Water Deficit ◽  
Anatomical Adaptations ◽  
Stipa Lagascae

AbstractStipa lagascae R. & Sch. (perennial bunchgrass) is one of the most promising steppic species for arid and desert lands of Tunisia. The present study was designed to study the effect of drought on root and leaf anatomy, water relationship, and the growth of three- month-old S. lagascae plants, submitted to water deficit (5, 10, 15, 20, 30 days of withheld irrigation) and grown in pots in greenhouse conditions. The results show that water deficit treatments reduced the biomass accumulation (MS) and leaf water potential (Ψw) of plants. However, leaf relative water content (RWC) decreased significantly only at severe drought. The root’s anatomical features showed reduced root cross-sectional diameter under water deficit. Conversely, epidermis was unaffected by water stress. Moderate and/or severe water deficit (20-30 days) reduced significantly the cortex thickness, cortical cell size, stele diameter, xylem vessel diameter and the stele/root crosssectional ratio, while the number of cortical cells increased for severe water deficit. The cuticles and mesophyll of S. lagascae was thickened by moderate to severe drought and the entire lamina thickness was increased significantly by 5.8% only after 30 days of water deficit while epidermis was unaffected by water deficit. However, severe water deficit (30 days) decreased the width and the length of the bundle sheath. At the same time, the mesophyll cells size and both the xylem and phloem vessels diameter diminished by 12, 16.8 and 17.5%, respectively. Leaf rolling occurs as a response to water deficit and its level increases as the drought period is progressing in plants while reduced bulliform cells size occurred only at severe water deficit. Our findings suggest a complex network of root and leaf anatomical adaptations such as a reduced vessel size with lesser cortical and mesophyll parenchyma formation and increased leaf rolling. These proprieties are required for the maintenance of water potential and energy storage under water stress which can improve the resistance of S. lagascae to survive in extremely arid areas

Genotypic differences in leaf area maintenance contribute to differences in recovery from water stress in soybean

2008 ◽  
Vol 59 (12) ◽  
pp. 1075 ◽  
Author(s):  
R. J. Lawn ◽  
A. A. Likoswe
Keyword(s):  
Leaf Area ◽  
Water Deficit ◽  
Leaf Tissue ◽  
Water Deficit Stress ◽  
Dead Leaf ◽  
Genotypic Differences ◽  
Leaf Stage ◽  
Severe Water Deficit ◽  
Soybean Plants ◽  
Root Effects

Genotypic effects on leaf survival during water deficit stress and subsequent recovery were evaluated using soybean plants grown in tall cylinders in the glasshouse. An initial experiment sought to verify reported genotypic differences in leaf area maintenance under severe water deficit stress. A second experiment sought to test the hypothesis that these putative differences might affect recovery after stress was relieved. Two shoot genotypes, G2120 and cv. Valder, reported to have high and low leaf area retention, respectively, were used in both experiments. In order to preclude the possibility that the reported differences between G2120 and Valder were related to root rather than shoot traits, each shoot was grafted at the cotyledonary stage onto 2 non-self root genotypes, cv. Leichhardt and PI416937. Leichhardt has an apparently normal root, while PI416937 has been reported to be ‘extensively fibrous-rooted’. In the first experiment, water was withheld at the first trifoliolate leaf stage and the plants subjected to terminal water deficit stress. Consistent with the previous report, leaf area was maintained for longer into the stress by the G2120 shoots, with rapid loss of lower leaves not starting until c. 90% of plant-available water (PAW) had been depleted, compared with c. 80% for Valder. The Valder leaves also showed more ‘firing’ damage, with large patches of dead leaf tissue on the retained leaves. Also consistent with the previous report, leaf epidermal conductance to water vapour was lower in G2120 than in Valder. There were no apparent root effects. In the second experiment, water was again withheld at the first trifoliolate leaf stage, and treatments were re-watered when 80%, 85%, 90%, and 95% of the estimated PAW was extracted. Again, G2120 shoots showed better leaf area maintenance during the drying cycle, and less firing damage. When the plants were re-watered, the re-growth of G2120 generally exceeded that of Valder at all levels of PAW depletion. The differences in recovery between G2120 and Valder shoots were sufficient to have agronomic relevance, and confirmed the hypothesis that leaf area retention can affect recovery after severe water deficit stress. Root effects were relatively small. During the drying cycle, leaflet growth was marginally enhanced by Leichhardt relative to PI416937 roots. After re-watering, there was stronger recovery of plants with PI416937 roots, especially those with G2120 shoots. The basis of the differences between the root genotypes is not known but the stronger recovery of PI416937 may reflect its putative ‘extensively fibrous’ nature.

Effects of Irrigation and Potassium Fertilizer Applications on Jujube Production

2021 ◽  
Vol 37 (4) ◽  
pp. 701-711
Author(s):  
Pengrui Ai ◽  
Yingjie Ma ◽  
Ying Hai
Keyword(s):  
Water Deficit ◽  
Economic Performance ◽  
Deficit Irrigation ◽  
Economic Benefit ◽  
Growth Parameters ◽  
Economic Benefits ◽  
Growth And Yield ◽  
List Type ◽  
Potassium Fertilizer ◽  
Severe Water Deficit

Highlights Moderate water deficit will help reduce agricultural investment. Application of potassium fertilizer can alleviate the effect of water deficit on fruit trees. Reasonable ratio of water and fertilizer is helpful to improve economic benefits. Abstract . The jujube planting industry is a key agricultural industry in Xinjiang, China. With an arid climate and limited water resources, Xinjiang must implement more efficient water-saving irrigation systems to guarantee the sustainable development of jujube planting industry. A two-factor, three-level test was adopted to explore how regulated deficit irrigation and different potassium fertilizer levels affected the growth and yield of jujube under drip irrigation. The results of analysis of variance showed that water deficit significantly affected photosynthetic characteristics, growth parameters, evapotranspiration, and yield. The effect of K-application level was focused on fruit volume and yield. However, when the ratio of water to fertilizer is unbalanced (150% K-application + severe water deficit), the growth of jujube trees be inhibited, and the fruit volume and economic benefits reduced by 7% and 11%, respectively. Means comparison indicated that growth parameters, evaporation, and yield under minor water deficit was lower than that under the adequate irrigation by 7%, 13%, and 6%, respectively; and economic performance was higher by 12%. Severe water deficit reduced growth parameters and economic benefits by 33% and 55%, respectively. Thus, minor water deficit irrigation significantly inhibited luxury transpiration and growth redundancy, improved water-use efficiency and increased economic performance. Severer water deficit may damage trees and negatively affect the jujube industry. With economic benefit analysis, 150% K-application with adequate irrigation and minor water deficit, 100% K-application with adequate irrigation and minor water deficit, 50% K-application with minor water deficit all achieve high economic benefits (14074~17261 RmB ha-1). However, when taking water restrictions, the environmental and economic costs of fertilizer, and the long-term effects of tree development into account, application of 100% K-application with minor water deficit (irrigation, 75% ETc; fertilizer, 200 kg ha-1 compound fertilizer+360 kg ha-1 potassium fertilizer) is recommended. Keywords: Deficit irrigation, Economic benefit, Potassium fertilizer, Yield.

Postharvest floral organ fall in Geraldton waxflower (Chamelaucium uncinatum Schauer)

1993 ◽  
Vol 33 (4) ◽  
pp. 481 ◽  
Author(s):  
DC Joyce
Keyword(s):  
Water Deficit ◽  
Room Temperature ◽  
Floral Organ ◽  
Vase Life ◽  
Naphthaleneacetic Acid ◽  
Fungal Development ◽  
Compression Load ◽  
Severe Water Deficit ◽  
Flower Abscission ◽  
Chamelaucium Uncinatum

Possible reasons for, and prevention of, postharvest floral organ fall in Geraldton waxflower (Chamelaucium unciizatum Schauer) were studied. An 11-kg compression load, equivalent to the lidding of a carton, caused flower fall amounting to 1% of the fresh mass of 420-g bunches. Fungal development also resulted in flower abscission. Healthy flowers produced little ethylene (e.g. 0.05 �L/kg.h), while infected flowers produced much more (e.g. 7.71 �L/kg.h) and were shed. Treatment with fungicide (iprodione + mancozeb) and antiethylene compounds [e.g. silver thiosulfate (STS) pulse, Purafil sorbant] reduced flowerfall in packaged flowers. Cut sprigs which suffered severe water deficit also shed flowers. In cv. Elegance, drying to -3.61 MPa elevated ethylene production (e.g. 1.35 �L/kg . h). Flowerfall induced by water deficit could be reduced by pretreatment with a STS pulse (0.5 mmol Ag+/L for 15-22 h at 0�C or 4 mmol Ag+/L for 20-30 min at about 20�C). Pretreatment with a naphthaleneacetic acid dip (50 mg/L for 1 min at room temperature) shortened the vase life of Elegance.

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