Xerophyte
Axerophyte(fromGreekξηρόςxeros'dry' + φυτόνphuton'plant') is a species ofplantthat hasadaptationsto survive in an environment with little liquid water. Examples of xerophytes includecacti,pineappleand somegymnosperm plants.Themorphologyandphysiologyof xerophytes are adapted to conserve water during dry periods. Some species called resurrection plants can survive long periods of extreme dryness ordesiccationof theirtissues,during which theirmetabolic activitymay effectively shut down. Plants with such morphological and physiological adaptations are said to bexeromorphic.[1]Xerophytes such as cacti are capable of withstanding extended periods of dry conditions as they have deep-spreading roots and capacity to store water. Their waxy, thorny leaves prevent loss of moisture.
Introduction[edit]
Plants absorb water from the soil, which then evaporates from their shoots and leaves; this process is known astranspiration.If placed in a dry environment, a typicalmesophyticplant would evaporate water faster than the rate of water uptake from the soil, leading towiltingand even death.
Xerophytic plants exhibit a diversity of specialized adaptations to survive in such water-limiting conditions. They may use water from their own storage, allocate water specifically to sites of newtissuegrowth, or lose less water to the atmosphere and so channel a greater proportion of water from the soil tophotosynthesisand growth. Different plant species possess different qualities and mechanisms to manage water supply, enabling them to survive.
Cactiand othersucculentsare commonly found in deserts, where there is little rainfall. Other xerophytes, such as certainbromeliads,can survive through both extremely wet and extremely dry periods and can be found in seasonally-moist habitats such as tropical forests, exploiting niches where water supplies are too intermittent for mesophytic plants to survive. Likewise,chaparralplants are adapted toMediterranean climates,which have wet winters and dry summers.
Plants that live underarctic conditionsalso have a need for xerophytic adaptations, since water is unavailable for uptake when the ground is frozen, such as the Europeanresurrection plantsHaberlea rhodopensisandRamonda serbica.[2]
In environments with very high salinity, such asmangrove swampsand semi-deserts, water uptake by plants is a challenge due to the high salt ion levels. Such environments may cause an excess of ions to accumulate in the cells, which is very damaging.[3]Halophytesand xerophytes evolved to survive in such environments. Some xerophytes may also be considered halophytes; however, halophytes are not necessarily xerophytes. The succulent xerophyteZygophyllum xanthoxylum,for example, has specialised protein transporters in its cells which allows storage of excess ions in theirvacuolesto maintain normalcytosolicpH and ionic composition.[4][5]
There are many factors which affect water availability, which is the major limiting factor of seedgermination,seedling survival, and plant growth. These factors include infrequent raining, intense sunlight and very warm weather leading to faster water evaporation. An extreme environmental pH and high salt content of water also disrupt plants' water uptake.
Types[edit]
Succulent plantsstore water in their stems or leaves. These include plants from the familyCactaceae,which have round stems and can store a lot of water. The leaves are oftenvestigial,as in the case of cacti, wherein the leaves are reduced to spines, or they do not have leaves at all. These include the C4 perennial woody plant,Haloxylon ammodendronwhich is a native of northwest China.
Non-succulent perennials successfully endure long and continuous shortage of water in the soil. These are hence called 'true xerophytes' or euxerophytes. Water deficiency usually reaches 60–70% of their fresh weight, as a result of which the growth process of the whole plant is hindered during cell elongation. The plants which survive drought are, understandably, small and weak.
Ephemeralsare the 'drought escaping' kind, and not true xerophytes. They do not really endure drought, only escape it. With the onset of rainfall, the plant seeds germinate, quickly grow to maturity, flower, and set seed, i.e., the entire life cycle is completed before the soil dries out again. Most of these plants are small, roundish, dense shrubs represented by species ofPapilionaceae,some inconspicuousCompositae,a fewZygophyllaceaeand some grasses. Water is stored in thebulbsof some plants, or at below ground level. They may be dormant during drought conditions and are, therefore, known as drought evaders.
Shrubs which grow in arid and semi-arid regions are also xeromorphic. For example,Caragana korshinskii,Artemisia sphaerocephala,andHedysarum scopariumare shrubs potent in the semi-arid regions of the northwest China desert. Thesepsammophileshrubs are not only edible to grazing animals in the area, they also play a vital role in the stabilisation of desert sand dunes.[6]
Bushes, also called semi-shrubs often occur in sandy desert region, mostly in deep sandy soils at the edges of the dunes. One example is theReaumuria soongorica,a perennial resurrection semi-shrub. Compared to other dominant arid xerophytes, an adultR. soongorica,bush has a strong resistance towater scarcity,hence, it is considered a super-xerophytes.[6]
Importance of water conservation[edit]
If thewater potential(or strictly, water vapour potential) inside a leaf is higher than outside, the water vapour willdiffuseout of the leaf down this gradient. This loss of water vapour from the leaves is calledtranspiration,and the water vapour diffuses through the openstomata.Transpiration is natural and inevitable for plants; a significant amount of water is lost through this process. However, it is vital that plants living in dry conditions are adapted so as to decrease the size of the open stomata, lower the rate of transpiration, and consequently reduce water loss to the environment. Without sufficient water, plant cells loseturgor,This is known asplasmolysis.If the plant loses too much water, it will pass itspermanent wilting point,and die.[7]
In brief, the rate of transpiration is governed by the number ofstomata,stomatal aperture i.e. the size of the stoma opening, leaf area (allowing for more stomata), temperature differential, the relative humidity, the presence of wind or air movement, the light intensity, and the presence of a waxy cuticle. It is important to note, that whilst it is vital to keep stomata closed, they have to be opened for gaseous exchange in respiration and photosynthesis.
Morphological adaptations[edit]
Xerophytic plants may have similar shapes, forms, and structures and look very similar, even if the plants are not very closely related, through a process calledconvergent evolution.For example, some species ofcacti,which evolved only in the Americas, may appear similar toeuphorbias,which are distributed worldwide. An unrelated species ofcaudiciformsplants with swollen bases that are used to store water, may also display some similarities.
Under conditions of water scarcity, the seeds of different xerophytic plants behave differently, which means that they have different rates of germination since water availability is a major limiting factor. These dissimilarities are due tonatural selectionand eco-adaptation as the seeds and plants of each species evolve to suit their surrounding.[8]
Reduction of surface area[edit]
Xerophytic plants typically have lesssurface to volume ratiothan other plants, so as to minimize water loss by transpiration and evaporation. They can may have fewer and smaller leaves or fewer branches than other plants. An example of leaf surface reduction is thespinesof a cactus, while the effects of compaction and reduction of branching can be seen in thebarrel cacti.Other xerophytes may have their leaves compacted at the base, as in abasal rosette,which may be smaller than the plant's flower. This adaptation is exhibited by someAgaveandEriogonumspecies, which can be found growing nearDeath Valley.
Forming water vapour-rich environment[edit]
Some xerophytes have tiny hair on their surfaces to provide a wind break and reduce air flow, thereby reducing the rate of evaporation. When a plant surface is covered with tiny hair, it is called tomentose. Stomata is located in these hair or in pits to reduce their exposure to wind. This enables them to maintain a humid environment around them.
In a still, windless environment, the areas under the leaves or spines where transpiration takes place form a small localised environment that is more saturated with water vapour than normal. If this concentration of water vapour is maintained, the external water vapour potential gradient near the stomata is reduced, thus, reducing transpiration. In a windier situation, this localisation is blown away and so the external water vapour gradient remains low, which makes the loss of water vapour from plant stomata easier. Spines and hair trap a layer of moisture and slows air movement over tissues.
Reflective features[edit]
The color of a plant, or of the waxes or hair on its surface, may serve to reflect sunlight and reduce transpiration. An example is the white chalkyepicuticular waxcoating ofDudleya brittonii,which has the highestultraviolet light(UV)reflectivityof any known naturally-occurring biological substance.[9]
Cuticles[edit]
Many xerophytic species have thickcuticles.[citation needed]Just like human skin, a plant's cuticles are the first line of defense for its aerial parts. As mentioned above, the cuticle contains wax for protection againstbioticandabioticfactors. Theultrastructureof the cuticles varies in different species. Some examples areAntizoma miersiana,Hermannia disermifoliaandGalenia africanawhich are xerophytes from the same region inNamaqualand,but have different cuticle ultrastructures.
A. miersianahas thick cuticle as expected to be found on xerophytes, butH. disermifoliaandG. africanahave thin cuticles.[citation needed]Since resources are scarce in arid regions, there is selection for plants having thin and efficient cuticles to limit the nutritional and energy costs for the cuticle construction.
In periods of severe water stress and stomata closure, the cuticle's low water permeability is considered one of the most vital factors in ensuring the survival of the plant. The rate of transpiration of the cuticles of xerophytes is 25 times lower than that of stomatal transpiration. To give an idea of how low this is, the rate of transpiration of the cuticles of mesophytes is only 2 to 5 times lower than stomatal transpiration. [10]
Physiological adaptations[edit]
There are many changes that happen on the molecular level when a plant experiences stress. When in heat shock, for example, theirprotein moleculestructures become unstable, unfold, or reconfigure to become less efficient. Membrane stability will decrease inplastids,which is why photosynthesis is the first process to be affected by heat stress.[11]Despite the many stresses, xerophytes have the ability to survive and thrive in drought conditions due to their physiological andbiochemicalspecialties.
Water storage[edit]
Some plants can store water in theirrootstructures,trunkstructures,stems,andleaves.Water storage in swollen parts of the plant is known as succulence. A swollen trunk or root at the ground level of a plant is called acaudexand plants with swollen bases are calledcaudiciforms.
Production of protective molecules[edit]
Plants may secreteresinsandwaxes(epicuticular wax) on their surfaces, which reducetranspiration.Examples are the heavily scented and flammable resins (volatile organic compounds) of somechaparralplants, such asMalosma laurina,or the chalky wax ofDudleya pulverulenta.
In regions continuously exposed to sunlight,UV rayscan cause biochemical damage to plants, and eventually lead toDNA mutationsand damages in the long run. When one of the main molecules involved in photosynthesis,photosystem II (PSII)is damaged by UV rays, it induces responses in the plant, leading to thesynthesisof protectant molecules such asflavonoidsand more wax. Flavonoids are UV-absorbing and act like sunscreen for the plant.
Heat shock proteins (HSPs)are a major class of proteins in plants and animals which are synthesised in cells as a response to heat stress. They help prevent protein unfolding and help re-fold denatured proteins. As temperature increases, the HSP protein expression also increases.[11]
Evaporative cooling[edit]
Evaporative cooling via transpiration can delay the effects of heat stress on the plant. However, transpiration is very expensive if there is water scarcity, so generally this is not a good strategy for the plants to employ.[11]
Stomata closure[edit]
Most plants have the ability to close their stomata at the start of water stress, at least partially, to restrict rates of transpiration.[12]They use signals orhormonessent up from the roots and through the transpiration stream. Since roots are the parts responsible for water searching and uptake, they can detect the condition of dry soil. The signals sent are anearly warning system- before the water stress gets too severe, the plant will go into water-economy mode.[11]
As compared to other plants, xerophytes have an inverted stomatal rhythm. During the day and especially during mid-day when the sun is at its peak, most stomata of xerophytes are close. Not only do more stomata open at night in the presence of mist or dew, the size of stomatal opening or aperture is larger at night compared to during the day. This phenomenon was observed in xeromorphic species ofCactaceae,Crassulaceae,andLiliaceae.
As theepidermisof the plant is covered with water barriers such asligninand waxy cuticles, the night opening of the stomata is the main channel for water movement for xerophytes in arid conditions.[12]Even when water is not scarce, the xerophytesA. Americanaandpineappleplant are found to utilise water more efficiently than mesophytes.[12]
Phospholipid saturation[edit]
Theplasma membrane of cellsare made up of lipid molecules calledphospholipids.These lipids become more fluid when temperature increases. Saturated lipids are more rigid than unsaturated ones i.e. unsaturated lipids becomes fluid more easily than saturated lipids. Plant cells undergo biochemical changes to change their plasma membrane composition to have more saturated lipids to sustain membrane integrity for longer in hot weather.[11]
If the membrane integrity is compromised, there will be no effective barrier between the internal cell environment and the outside. Not only does this mean the plant cells are susceptible to disease-causing bacteria and mechanical attacks by herbivores, the cell could not perform its normal processes to continue living - the cells and thus the whole plant will die.[13]
Xanthophyll cycle[edit]
Light stress can be tolerated by dissipating excess energy as heat through thexanthophyll cycle.Violaxanthin and zeaxanthin arecarotenoidmolecules within thechloroplastscalled xanthophylls. Under normal conditions, violaxanthin channels light to photosynthesis. However, high light levels promote the reversible conversion of violaxanthin to zeaxanthin. These two molecules are photo-protective molecules.
Under high light, it is unfavourable to channel extra light into photosynthesis because excessive light may cause damage to the plant proteins. Zeaxanthin dissociates light-channelling from the photosynthesis reaction - light energy in the form ofphotonswill not be transmitted into the photosynthetic pathway anymore.[11]
CAM mechanism[edit]
Stomata closurenot only restricts the movement of water out of the plant, another consequence of the phenomenon is thatcarbon dioxideinflux or intake into the plant is also reduced. As photosynthesis requires carbon dioxide as a substrate to produce sugar for growth, it is vital that the plant has a very efficientphotosynthesissystem which maximises the utilisation of the little carbon dioxide the plant gets.
Many succulent xerophytes employ theCrassulacean acid metabolismor better known as CAM photosynthesis. It is also dubbed the "dark" carboxylation mechanism because plants in arid regions collect carbon dioxide at night when the stomata open, and store the gases to be used for photosynthesis in the presence of light during the day. Although most xerophytes are quite small, this mechanism allows a positivecarbonbalance in the plants to sustain life and growth. Prime examples of plants employing the CAM mechanism are thepineapple,Agave Americana,andAeonium haworthii.[12]
Although some xerophytes perform photosynthesis using this mechanism, the majority of plants in arid regions still employ the C3and C4photosynthesis pathways. A small proportion of desert plants even use a collaborated C3-CAM pathway.[14]
Delayed germination and growth[edit]
The surrounding humidity and moisture right before and during seed germination play an important role in the germination regulation in arid conditions. An evolutionary strategy employed by desert xerophytes is to reduce the rate of seed germination. By slowing the shoot growth, less water is consumed for growth and transpiration. Thus, the seed and plant can utilise the water available from short-lived rainfall for a much longer time compared to mesophytic plants.[6]
Resurrection plants and seeds[edit]
During dry times, resurrection plants look dead, but are actually alive. Some xerophytic plants may stop growing and go dormant, or change the allocation of the products of photosynthesis from growing new leaves to the roots.[11][15]These plants evolved to be able to coordinately switch off their photosynthetic mechanism without destroying the molecules involved in photosynthesis. When water is available again, these plants would "resurrect from the dead" and resume photosynthesis, even after they had lost more than 80% of their water content.[16]A study has found that the sugar levels in resurrection plants increase when subjected to desiccation. This may be associated with how they survive without sugar production via photosynthesis for a relatively long duration.[17]Some examples of resurrection plants include theAnastatica hierochunticaplant or more commonly known as theRose of Jericho,as well as one of the most robust plant species in East Africa,Craterostigma pumilum.[18][19] Seeds may be modified to require an excessive amount of water before germinating, so as to ensure a sufficient water supply for the seedling's survival. An example of this is theCalifornia poppy,whose seeds lie dormant during drought and then germinate, grow, flower, and form seeds within four weeks of rainfall.
Leaf wilting and abscission[edit]
If the water supply is not enough despite the employment of other water-saving strategies, the leaves will start to collapse and wilt due to waterevaporationstill exceeding water supply. Leaf loss (abscission) will be activated in more severe stress conditions.Drought deciduousplants may drop their leaves in times of dryness.
The wilting of leaves is a reversible process, however, abscission is irreversible. Shedding leaves is not favourable to plants because when water is available again, they would have to spend resources to produces new leaves which are needed for photosynthesis.[11]Exceptions exist, however, such as theocotillowhich will shed its leaves during prolonged dry seasons in the desert, then re-leaf when conditions have improved.
Modification of environment[edit]
Theleaf litteron the ground around a plant can provide an evaporative barrier to prevent water loss.[citation needed]A plant's root mass itself may also hold organic material that retains water, as in the case of the arrowweed (Pluchea sericea).
Mechanism table[edit]
| Mechanism | Adaptation | Examples |
|---|---|---|
| Water uptake | Extensive root system | Acacia,Prosopis |
| Water storage | Succulence | Kalanchoe,Euphorbia |
| Fleshy tuber | Raphionacme | |
| Reduce water loss | Surface area reduction | Barrel cactus,Basal rosette,Eriogonum compositum |
| Sunken stomata and hairs | Pine,Nassauvia falklandica,Bromeliads | |
| Waxy leaf surface | Prickly pear,Malosma laurina,Dudleya pulverulenta | |
| Nocturnal stomata | Tea plant,Alfalfa,Brachychiton discolor,Quercus trojana | |
| CAM photosynthesis | Cactus,Pineapple plant,Agave Americana,Aeonium haworthii,Sansevieria trifasciata | |
| Curled leaves | Esparto grass | |
| Dormancy and reduced photosynthesis | Resurrection plants | Ramonda nathaliae,Ramonda myconi,Haberlea rhodopensis,Anastatica,Craterostigma pumilum |
| Dormant seeds | Californian poppy | |
| Leaf abscission | Coastal sage scrub,Wiliwili,Geoffroea decorticans |
Uses[edit]
Land degradationis a major threat to many countries such as China and Uzbekistan. The major impacts include the loss of soil productivity and stability, as well as theloss of biodiversitydue to reducedvegetationconsumed by animals.[20]In arid regions where water is scarce and temperatures are high, mesophytes will not be able to survive, due to the many stresses. Xerophytic plants are used widely to preventdesertificationand for fixation of sand dunes. In fact, in northwest China, the seeds of three shrub species namelyCaraganakorshinskii, Artemisia sphaerocephala, andHedysarumscopariumare dispersed across the region. These shrubs have the additional property of being palatable to grazing animals such as sheep and camels.H. scopariumis under protection in China due to it being a major endangered species.[6]Haloxylon ammodendronandZygophyllumxanthoxylumare also plants that form fixed dunes.[21]
A more well-known xerophyte is the succulent plantAgave americana.It is cultivated as an ornamental plant popular across the globe. Agave nectar is garnered from the plant and is consumed as a substitute for sugar or honey. In Mexico, the plant's sap is usually fermented to produce an alcoholic beverage.
Many xerophytic plants produce colourful vibrant flowers and are used for decoration and ornamental purposes in gardens and in homes. Although they have adaptations to live in stressful weather and conditions, these plants thrive when well-watered and in tropical temperatures.Phloxsibiricais rarely seen in cultivation and does not flourish in areas without long exposure to sunlight.[citation needed]
A study has shown that xerophytic plants which employ theCAM mechanismcan solve micro-climate problems in buildings of humid countries. The CAM photosynthetic pathway absorbs the humidity in small spaces, effectively making the plant such asSansevieria trifasciataa natural indoor humidity absorber. Not only will this help with cross-ventilation, but lowering the surrounding humidity increases the thermal comfort of people in the room. This is especially important in East Asian countries where both humidity and temperature are high.[22]
Recent years has seen interests in resurrection plants other than their ability to withstand extreme dryness. The metabolites, sugar alcohols, and sugar acids present in these plants may be applied as natural products for medicinal purposes and in biotechnology. During desiccation, the levels of the sugars sucrose, raffinose, and galactinol increase; they may have a crucial role in protecting the cells against damage caused byreactive oxygen species(ROS) and oxidative stress. Besides having anti-oxidant properties, other compounds extracted from some resurrection plants showedanti-fungalandanti-bacterialproperties. Aglycosidefound inHaberlea rhodopensiscalled myconoside is extracted and used in cosmetic creams as a source of anti-oxidant as well as to increase elasticity of the human skin.[23]Although there are other molecules in these plants that may be of benefit, it is still much less studied than theprimary metabolitesmentioned above.[24]
See also[edit]
- Index: Desert flora
- Arid Forest Research Institute(AFRI)
- Arizona Cactus Botanical Garden
- Drought tolerance
- Halophyte
- Hydrophyte
- International Center for Agricultural Research in the Dry Areas
- International Crops Research Institute for the Semi-Arid Tropics
- Kinetic Theory
- Raunkiær plant life-form
- Xeriscaping
- Xerocole
References[edit]
- ^”Xeromorphic”, The Cambridge Illustrated Glossary of Botanical Terms, Michael Hickey, Clive King, Cambridge University Press, 2001
- ^Gechev, Tsanko S.; Hille, Jacques; Woerdenbag, Herman J.; Benina, Maria; Mehterov, Nikolay; Toneva, Valentina; Fernie, Alisdair R.; Mueller-Roeber, Bernd (2014-11-01)."Natural products from resurrection plants: Potential for medical applications".Biotechnology Advances.32(6): 1091–1101.doi:10.1016/j.biotechadv.2014.03.005.ISSN0734-9750.PMID24681091.
- ^Liu, Hua; Wang, Qiuqing; Yu, Mengmeng; Zhang, Yanyan; Wu, Yingbao; Zhang, Hongxia (2008)."Transgenic salt-tolerant sugar beet (Beta vulgaris L.) constitutively expressing an Arabidopsis thaliana vacuolar Na/H antiporter gene, AtNHX3, accumulates more soluble sugar but less salt in storage roots".Plant, Cell & Environment.31(9): 1325–1334.doi:10.1111/j.1365-3040.2008.01838.x.ISSN1365-3040.PMID18518917.
- ^Wu, Guo-Qiang; Wang, Qian; Bao, Ai-Ke; Wang, Suo-Min (1 March 2011). "Amiloride Reduces Sodium Transport and Accumulation in the Succulent Xerophyte Zygophyllum xanthoxylum Under Salt Conditions".Biological Trace Element Research.139(3): 356–367.doi:10.1007/s12011-010-8662-9.ISSN0163-4984.PMID20352373.S2CID7477284.
- ^McNair, J.B. (1943). "Hydrophytes, xerophytes and halophytes and the production of alkaloids, cyanogenetic and organic sulphur compounds".Lloydia.6:1–17.
- ^abcdZeng, Yan Jun; Wang, Yan Rong; Zhang, Ju Ming (April 2010). "Is reduced seed germination due to water limitation a special survival strategy used by xerophytes in arid dunes?".Journal of Arid Environments.74(4): 508–511.Bibcode:2010JArEn..74..508Z.doi:10.1016/j.jaridenv.2009.09.013.
- ^"3.1.4 - Turgor loss, cytorrhysis, and plasmolysis | Plants in Action".plantsinaction.science.uq.edu.au.Retrieved2018-03-21.
- ^Ibañez, A.N.; Passera, C.B. (February 1997). "Factors affecting the germination of albaida (Anthyllis cytisoidesL.), a forage legume of the Mediterranean coast".Journal of Arid Environments.35(2): 225–231.Bibcode:1997JArEn..35..225I.doi:10.1006/jare.1995.0142.
- ^Mulroy, Thomas W. (1979). "Spectral properties of heavily glaucous and non-glaucous leaves of a succulent rosette-plant".Oecologia.38(3): 349–357.Bibcode:1979Oecol..38..349M.doi:10.1007/BF00345193.PMID28309493.S2CID23753011.
- ^Jordaan, A.; Kruger, H. (February 1998)."Notes on the cuticular ultrastructure of six xerophytes from southern Africa".South African Journal of Botany.64(1): 82–85.doi:10.1016/S0254-6299(15)30829-2.
- ^abcdefghTurnbull, C. (2017)LS1-OB.34 - Plant stress.
- ^abcdGINDEL, I. (April 1970). "The Nocturnal Behaviour of Xerophytes Grown Under Arid Conditions".New Phytologist.69(2): 399–404.doi:10.1111/j.1469-8137.1970.tb02438.x.
- ^McNeil, Paul L.; Steinhardt, Richard A. (7 April 1997)."Loss, Restoration, and Maintenance of Plasma Membrane Integrity".The Journal of Cell Biology.137(1): 1–4.doi:10.1083/jcb.137.1.1.ISSN0021-9525.PMC2139853.PMID9105031.
- ^Atia, Abdallah; Rabhi, Mokded; Debez, Ahmed; Abdelly, Chedly; Gouia, Houda; Haouari, ChirazChaffei; Smaoui, Abderrazak (1 December 2014)."Ecophysiological aspects in 105 plants species of saline and arid environments in Tunisia".Journal of Arid Land.6(6): 762–770.Bibcode:2014JArL....6..762A.doi:10.1007/s40333-014-0028-2.ISSN1674-6767.
- ^"Plant Adaptations".University of New Mexico. Archived fromthe originalon January 4, 2015.RetrievedDecember 2,2014.
- ^Schwab, K. B.; Schreiber, U.; Heber, U. (1989-02-01). "Response of photosynthesis and respiration of resurrection plants to desiccation and rehydration".Planta.177(2): 217–227.Bibcode:1989Plant.177..217S.doi:10.1007/bf00392810.ISSN0032-0935.PMID24212344.S2CID23789946.
- ^Muller, Joachim; Sprenger, Norbert; Bortlik, Karlheinz; Boller, Thomas; Wiemken, Andres (1997). "Desiccation increases sucrose levels in Ramonda and Haberlea, two genera of resurrection plants in the Gesneriaceae".Physiologia Plantarum.100:153–158.doi:10.1111/j.1399-3054.1997.tb03466.x.
- ^Zia, Ahmad; Walker, Berkley J.; Oung, Hui Min Olivia; Charuvi, Dana; Jahns, Peter; Cousins, Asaph B.; Farrant, Jill M.; Reich, Ziv; Kirchhoff, Helmut (September 2016)."Protection of the photosynthetic apparatus against dehydration stress in the resurrection plant".The Plant Journal.87(6): 664–680.doi:10.1111/tpj.13227.PMID27258321.
- ^"Craterostigma pumilum - Alpine Garden Society - Plant Encyclopaedia".encyclopaedia.alpinegardensociety.net.
- ^Toderich, K. N.; Shuyskaya, E. V.; Rajabov, T. F.; Ismail, Shoaib; Shaumarov, M.; Yoshiko, Kawabata; Li, E. V. (2013).Combating Desertification in Asia, Africa and the Middle East.Springer, Dordrecht. pp. 249–278.doi:10.1007/978-94-007-6652-5_13.ISBN9789400766518.
- ^Kang, Jianjun; Duan, Jiaojiao; Wang, Suomin; Zhao, Ming; Yang, Zihui (2013)."Na compound fertilizer promotes growth and enhances drought resistance of the succulent xerophyteHaloxylonammodendron ".Soil Science and Plant Nutrition.59(2): 289–299.Bibcode:2013SSPN...59..289K.doi:10.1080/00380768.2012.763183.S2CID93593296.
- ^Prijambada, Erlina; Sudikno, Antariksa; Murti Nugroho, Agung; Leksono, Amin (2016-03-01)."Sansevieria trifasciatas, xerophyte as indoor humidity absorber of small type residences 1".Ecology, Environment and Conservation.22.
- ^Dell’Acqua, G.; Schweikert, K. (April 2012). "Skin benefits of a myconoside-rich extract from resurrection plant Haberlea rhodopensis".International Journal of Cosmetic Science.34(2): 132–139.doi:10.1111/j.1468-2494.2011.00692.x.PMID22023081.S2CID9546089.
- ^Gechev, Tsanko S.; Hille, Jacques; Woerdenbag, Herman J.; Benina, Maria; Mehterov, Nikolay; Toneva, Valentina; Fernie, Alisdair R.; Mueller-Roeber, Bernd (1 November 2014)."Natural products from resurrection plants: Potential for medical applications".Biotechnology Advances.32(6): 1091–1101.doi:10.1016/j.biotechadv.2014.03.005.ISSN0734-9750.PMID24681091.
Further reading[edit]
- A. Fahn; David F. Cutler (1995).Xerophytes(First ed.). Borntraeger Science Publishers.ISBN978-3-443-14019-9.
- D. J. Taylor; N. P. O. Green; G. W. Stout (2001).Biological Science 1 & 2(Third ed.). Cambridge University Press.ISBN978-0-521-56178-5.
- L. Taiz; E. Zeiger; I. M. Møller; A. Murphy (2015).Plant Physiology and Development(Sixth ed.). Sinauer Associates Publishers.ISBN978-1-60535-255-8.
External links[edit]
